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The carbon-carbon double bonds (C C) in polychloroprene (PCP) was broken down by Schwartz's reagent ([Cp2ZrClH]n) under mild conditions. The reaction mechanism for cleaving C C bonds in PCP was studied in detail. It was found that the cleavage pathway was chlorine self-assisted β-alkyl elimination reaction, namely, β-alkyl elimination was promoted while chlorine in PCP was eliminated by releasing Cp2ZrCl2. The molecular weights of chain-scission products were controlled ranging from starting molecular weights of PCP to 0.2 kg mol−1; at the same time, microstructures of chain-scission products were similar to chain structures of original PCP. In addition, chain-scission products could be chain-end functionalized by electrophiles quenching chain scission reaction. More importantly, efficient catalytic chain cleavage was achieved under the synergistic effect of [Cp2ZrClH]n with both LiH and H2.

Poly(thienylene vinylene)s (PTVs) are close analogs to the extensively studied polythiophenes and the insertion of one double bond between every two thiophene units along the main-chain of PTV backbone eliminates steric repulsion and potentially allows installment of conjugated side-chains without significantly distorting the main-chain planarity, offering a facile way of fine-tuning the polymer electronic properties through main-chain/side-chain cross-conjugation. We describe here a new methodology that combines acyclic diene metathesis and post-polymerization modification methods for the access of a series of cross-conjugated PTVs bearing aromatic side-chains connected to the main-chains through alkyne spacers. Compared with unfunctionalized PTVs, these cross-conjugated PTVs showed broader absorption ranges, reduced bandgaps, and rarely observed fluorescence. Organic solar cells employing the cross-conjugated PTVs displayed up to double the efficiency improvement over those employing pristine PTVs. For the first time, these PTVs were applied as sensitizers in composites with g-C3N4 for photocatalytic hydrogen production. It was found that the relative energy level positions between the polymers and g-C3N4 and polymer crystallinity likely played decisive roles in determining the hydrogen production efficiencies, which gave us useful guidelines on future optimization of polymer structures and selection of photocatalytic systems.

Novel block copolymers were synthesized for the first time via nitroxide-mediated polymerization (NMP) using ethylene glycol dicylopentenyl methacrylate (EGDEMA), which has a pendent double bond in the norbornene group, and farnesene (Far), a terpene-based diene. Homopoly(EGDEMA)) was synthesized successfully using Dispolreg 007 initiator without any co-monomer as typically required of NMP, and the macroinitiator was chain-extended with Far making poly(EGDEMA-b-Far) diblock copolymers. Due to the relatively low glass transition temperature (Tg) of poly(EGDEMA), the methacrylate block was also copolymerized statistically with isobornyl methacrylate (iBOMA) to add stiffness, then chain-extended with Far. Additionally, the pendent double bond of EGDEMA allowed for thiol-ene clicking of POSS units for further functionalization of these block copolymers. However, the conjugation efficiency of the thermally initiated thiol-ene clicking was low and resulted in low POSS incorporation (1.6–10 mol%), especially for block copolymers that included iBOMA due to its increased stiffness and steric hindrance. Nonetheless, the added POSS improved the thermal stability by minimizing the degradation of the 1,4-addition Far units, as well as the degradation of isobornyl units of iBOMA. The mechanical strength was also increased as POSS units reinforced the physical crosslinks of these block copolymers as shown by an increase in linear viscoelastic regions. Distinct Tgs were observed for the respective elastomeric poly(Far) block (~-70 °C) and thermoplastic block (30 °C for poly(EGDEMA) and 110 °C for poly(EGDEMA-co-iBOMA)), therefore suggesting microphase separation. An increase in Tg was also observed in all polymers with added POSS, further confirming the added stiffness provided by POSS. These poly(EGDEMA-b-Far) and poly(EGDEMA-co-iBOMA-b-Far) show great versatility as alternative TPE materials, with improved mechanical and thermal properties added by functionalization of POSS.

Bentonite is a natural clay mineral with high cationic exchange properties and plays an important role in organic-inorganic composite hydrogels. We report an organic-inorganic cross-linked self-healing hydrogel with excellent mechanical properties by introducing acrylic acid-modified bentonite (AABT) into its cross-link network. AABT with unsaturated double bonds was co-polymerized with AA to construct the hybrid cross-link network of the hydrogel. Then, the carboxyl groups in the PAA chain reacted with CS to form a physically cross-linked network with a hydrogen bond structure. As confirmed by FTIR, XRD, XPS and SEM, the AABT participated in the formation of the hydrogel network, and the hydrogen bonds between PAA and CS chains were formed. Our AABT-PAA/CS hydrogels possessed tensile strength, compressive modulus and elongation at break as high as 0.96 MPa, 4.5 MPa and 1331%, respectively. Besides, our hydrogels also exhibited excellent self-healing properties, with recovered rate stress and strain of ~76.6% and ~77.7% after 4 h, respectively.

Macromolecular Cross-Metathesis (MCM) reactions on commercial Polybutadiene (PBD) and Polyisoprene (PIP) homopolymers, in the presence of first generation Grubbs and Hoveyda-Grubbs catalysts, are reported. 13C-NMR resonances of butadiene(B)/isoprene(I) heterosequences show block-copolymer formation, with blocks longer than a hundred monomer units, even for long reaction times. DSC scans of MCM products show that, with MCM time, PBD crystallinity progressively disappears while the well separated Tg of the two homopolymers merge to an intermediate single Tg. This indicates that PBD and PIP blocks are completely miscible when their lengths are reduced to a few hundred units. 13C NMR spectra also show that, for the considered MCM process, double bond isomerizations are definitely more frequent than heterosequence formations.

Cationic polymerization of two styrene derivatives containing carbazole moiety with different linking topology, 9-(4-vinylphenyl)carbazole (M1) and 3-(4-vinylphenyl)-9-ethylcarbazole (M2), using 1-chloro-1-phenylethane (PhEtCl)/SnCl4 initiating system has been investigated. It was shown that polymerization of M1, which is characterized by higher electron density on the carbon at the 3 position of carbazolyl group than on vinyl group, proceeds predominantly via step-growth (SG) pathway through addition of protonated monomer/oligomers to 3-position of carbazolyl group (electrophilic aromatic substitution). On the contrary, M2, in which 3-position of carbazolyl group is protected via introduction of 4-vinylphenyl group, polymerized predominantly via chain-growth (CG) pathway through addition of carbocation to double bond of monomer. The polymers synthesized via SG mechanism showed different photophysical characteristics in comparison with corresponding monomer, while in case of polymers prepared via CG mechanism the polymer and monomer have the same absorption and fluorescence profiles.

A polyelectrolyte membrane with anti-ultraviolet, anti-fouling, and antibacterial abilities was prepared using trimethyl quaternary ammonium salt grafting lignin (QAL) and polystyrene (PS) at different ratios. Contact angle measurements indicated that the addition of QAL into the PS blending membrane altered the hydrophilicity by trimethyl quaternary ammonium groups and phenolic hydroxyl groups of QAL. Furthermore, the phenylpropane structural unit in the lignin formed double bonds by conjugating with carbonyl groups and formed p-π by conjugating with phenolic hydroxyl of side chains. For this reason, the produced composite membranes displayed high potential and commercial importance for absorbing ultraviolet light. The ultraviolet transmission values of all the PS/QAL blending membranes were close to zero ranging from 200 to 400 nm. The QAL 5 -PS membrane had less variation in the gas transmission rate (−6.388 cm 3 /m 2 /day/atm) than that of PS membrane (−32.9 cm 3 /m 2 /day/atm) after 5 circles of bovine serum albumin (BSA) fouling. The inhibition zone of the QAL 5 -PS membrane was 10.4 ± 0.06 mm, and almost zero for the neat PS membrane, indicating a much better antibacterial performance of the QAL-PS composite membranes than that of pure PS membranes.

A diepoxide ((E)-1,2-di(7- oxabicyclo [4.1.0]heptan-3-yl)ethane, named DCE), possessing two cyclohexane rings bridged by a double bond was obtained via self-metathesis approach. This unique epoxy structure shows great potential in substantially overcoming the poor performances of plant oil materials in thermal and mechanical aspects. The molecular structure of DCE is more compact and regular than the commercial 3,4-epoxycyclohexylmethyl-3,4- epoxycyclohexanecarboxylate (ECHM) and was evidenced by the small-/wide-angle X-ray scattering. After conetwork was built between epoxidized soybean oil (ESO) and DCE, stiff crosslinks were created through the double bonds of DCE, which restricts the backbone rotation of ESO (P-ESO) networks. DCE-rich domains with dimensions ranging from 0.5 to 2 μm were observed with the increase of DCE, revealed by atomic force microscopy (AFM) phase image and voltage-distance curve. These DCE-rich domains act as micro-scale reinforcements homogenously dispersed in the ESO matrix, effectively sustaining the applied stress and preventing the chain break from high force loading. Compared to P-ESO, the co-polymerized ESO-DCE at 30 wt % DCE loading showed tensile strength of 62 MPa and glass transition temperature of 163 °C that are much higher than 4 MPa and 10 °C for P-ESO, respectively. ECHM also showed significant reinforcement effects on the thermal and mechanical properties of ESO, but DCE's reinforcement effects is doubled compared to ECHM.

A series of hydroxyl functionalized polybutadienes has been prepared by combining the oxidolysis and reduction of cis-polybutadiene rubber (BR). For the first time, multi-hydroxyl polybutadiene (MHPB) with α,ω- and intrachain hydroxyl groups was synthesized through the simultaneous reduction of –CHO and epoxy groups in epoxidized aldehyde group terminated polybutadiene (EATPB) by sodium dihydro-bis-(2-methoxyethoxy) aluminate (Red-Al). The corresponding hydroxyl functionalized polyethylenes, including hydroxyl-terminated polyethylene (HTPE), multi-hydroxyl polyethylene (MHPE) and hydroxyl-terminated polyethylene with ethyl branches (FHTPE), were readily obtained via the hydrogenation of C=C double bonds in the functionalized polybutadienes with TSH/TPA regents. The microstructures of all the products were confirmed by 1H NMR, 13C NMR and FT-IR, and their thermal properties were determined by TGA and DSC. It has been indicated that the linear HTPE and MHPE possessed high initial thermal degradation temperature, high degree of crystallinity, and high melting temperature due to their stereoregular microstructure. However, the FHTPE obtained through the hydrogenation of HTPB from free radical polymerization had much lower degree of crystallinity and melting temperature due to the presence of more ethyl branches.

The ring-opening copolymerization (ROCOP) of epoxides and CO2 provides an alternative approach towards polycarbonates and due to their aliphatic nature, they represent an interesting alternative to bisphenol-A based polycarbonates. A Lewis acidic β-diiminate (BDI)CF3-Zn-(SiMe3)2 complex 1 is used in the ROCOP of CO2 with cyclohexene oxide (CHO) and limonene oxide (LO), respectively. The knowledge gained from polymerizations monitored via in situ IR spectroscopy was used to upscale the reactions to a 1 L reactor. The two products poly(cyclohexene carbonate) (PCHC) and poly(limonene carbonate) (PLC) were then characterized via thermal analysis, a multiaxial pressure test, and dynamic mechanical analysis and compared with commercial polymers. While PCHC and PLC were both thermally stable at 150 °C for 20 min and only minor decomposition occurred at 180 °C, PLC is prone to cross-linking at elevated temperatures. This could be prevented by hydrogenation of the double bond or by the addition of an antioxidant. In the mechanical performance, the aliphatic polymers ranged between the highly impact resistant Durabio® and the brittle PMMA but broke without a splintering of the material. Overall, this study enabled a classification of CO2-based polycarbonates, especially of the novel PLC. Additionally, complex 1 was active in the terpolymerization of CHO, LO, and CO2. The formation of an actual terpolymer was confirmed via aliquot gel-permeation chromatography and diffusion-ordered NMR spectroscopy. High-pressure NMR techniques reveal an interesting kinetic feature. CHO gets copolymerized with CO2 exclusively, and LO incorporation only starts when CHO is fully consumed.

Poly (ether-ester) based hydrogels have been broadly used as degradable biomaterials in drug delivery systems and tissue engineering. However, they were synthesized with uncontrollable mechanical properties and inert to most of the biological activities, such as cell adhesion and stem cell differentiation. Herein, we synthesized a water-soluble copolymer with poly (trimethylene carbonate-co-2-methyl,2-methylacrylate-bimethylene carbonate) (PTMAc) and poly(ethylene glycol)(PEG) blocks (PCE), in which the PTMAc segments provided free active double bonds and can be further conjugated with thiol-ended peptides to improve its cytocompatibility. Meanwhile, the extra double bonds were crosslinked by Michael addition, forming hydrogels with precisely controlled mechanical strength. The chemical structure and molecular weight of the synthesized PCE were characterized by 1H NMR and gel permeation chromatography (GPC). The composition of the PCEs was controlled by changing the feed ratios of 2-methyl,2-methylacrylate-bimethylene carbonate (Ac) comonomer (fAc). It was noted that when the ratio of comonomers to the macroinitiator PEG ([M]0/[I]0 = 18) and the ratio of DL-Dithiothreitol (DTT) to Ac ([thiol]/[Ac] = 1/1) were fixed, the storage moduli of PCE hydrogels increased from 2 kPa to 10 kPa and the gelation time decreased with increasing fAc. The pendant double bonds were easily conjugated with CRGD to promote the neurite sprouting and axonal extension from the dorsal root ganglion (DRG) neurons. Moreover, the weaker the hydrogel matrix (G′ = 0.2 kPa) was, the lower the axon extension length was, but the axon diameter became thicker. An increase in modulus is beneficial to axon extension (5 kPa), while a high modulus (10 kPa) is unfavorable. These results demonstrated that this novel poly(ether-carbonate) based hydrogel can be introduced as a suitable scaffold for fast and effective nerve regeneration.

A cyclic polymethacrylate was prepared via the anionic polymerization of methyl methacrylate (MMA) initiated by a 1:1 adduct of methyl sorbate (MS) and a N-heterocyclic carbene (NHC) without the need for highly dilute conditions, because an α-terminal imidazolimium group is neighboring to the propagating anion during the polymerization. The polymerization proceeded quantitatively using methylaluminum bis(2,6-di-tert-butyl-4-methylphenoxide) (MAD) as the Lewis acid to give the poly (MMA) with the MS unit in the α-terminus, and an Mn of 7.2 × 103–29.1 × 103 with a molecular weight distribution (Mw/Mn = 1.16-1.56). From proton (1H) NMR and matrix assisted laser desorption/ionization (MALDI-TOF) mass spectra, coupled with size exclusion chromatography (SEC) of the poly (MMA) produced before and after ozonolysis of the internal carbon-carbon double bond in the MS unit, we found that ring-closing reaction was induced by nucleophilic substitution of the propagating anion to the neighboring carbon of the α-terminal carbenyl (imidazolimium) group to synthesize cyclic poly (MMA) following complete the monomer consumption.

The reactive blending system of free radical initiator (L101), polylactide (PLLA) and bio-based polyurethane (Bio-TPU) elastomer containing double bonds was investigated. There existed a competition for free radicals between the PLLA and Bio-TPU, because free radicals could attack both the tertiary hydrogen in PLLA chains and the double bonds in Bio-TPU. The behavior of competition for free radicals between PLLA and toughening phase was pointed out and analyzed in this work for the first time. Observations from all kinds of characterization lead us to believe that the double bonds in Bio-TPU were more prone to react with free radicals. The competition for free radicals played an important role on the interfacial properties of the blending systems, and consequently, on the thermal and mechanical properties of the blends. In PLLA/Bio-TPU/L101 (90/10/0.1, 90/10/0.3) blends, excellent ductility and high tensile strength were found at the same time owing to largely improved compatibility and much higher crystallinity. The elongation at break of these two samples were improved 36 and 34 times compared to pure PLLA separately, accompanied with only 16% and 18% decrease of the tensile strength. This work may be helpful for better understanding of similar reactive blending systems and designing PLLA blends with comprehensive properties.

We report in this paper an easy method for the synthesis of cylindrical polymer brushes with dendritic side chains through anionic reaction. The synthesis is accomplished by iteratively grafting a living block copolymer, polyisoprene-b-polystyrenyllithium (PI-b-PSLi), to the main chain and subsequently to the branches in a divergent way. PI segment is short and serves as a precursor for multifunctional branching unit. The grafting reaction involves two successive steps: i) epoxidation of internal double bonds of PI segments, either in main chain or side chains; ii) ring-opening addition to the resulting epoxy group by the living PI-b-PSLi. Repeating the two steps affords a series of cylindrical polymer brushes with up to 3rd generation and extremely high molecular weight. The branching multiplicity depends on the average number of oxirane groups per PI segment, usually ca. 8 in the present work. The high branching multiplicity leads to tremendous increase in molecular weights of the cylindrical products with generation growth. Several series of cylindrical polymer brushes with tunable aspect ratios are prepared using backbones and branches with controlled lengths. Shape anisotropy is investigated in dilute solution using light scattering technique. Worm-like single molecular morphology with large persistence length is observed on different substrates by atomic force microscopy.

Alkylacrylamide phosphonate monomers were synthesized by aza-Michael addition of an alkylamine onto the double bond of diethyl vinylphosphonate, then reaction with acryloyl chloride. Free radical copolymerization of n-butylacrylamide phosphonate with an acrylate-functional PEO macromonomer, then removal of the ethyl groups from the phosphonates led to poly(n-butylacrylamide phosphonic acid)-g-PEO copolymers. The copolymer comprising 56 wt% of the backbone and 44 wt% of PEO grafts was soluble in DMF, DMSO, methanol and water at pH 7.4. This copolymer formed aggregates in DMF and DMSO with only a few aggregates in methanol or water. Interaction of the phosphonic acid derivative (0.11 mmol) of n-butylacrylamide phosphonate with hydroxyapatite (0.15 or 0.30 mmol calcium ions) showed 80 and 95% extent of binding of the phosphonic acid whereas those values for acrylic acid were 47 and 64%. The hydrolytically stable polyacrylamide phosphonates with their excellent binding properties to hydroxyapatite make them potential candidates for adhesives.

A homopolymer strategy was developed to synthesize temperature and pH/CO 2 stimulus-responsive homopolymers. A new class of acrylamide monomers bearing oligo(ethylene glycol) unit and N,N -diethylaminoethyl group were designed and prepared through Aza-Michael addition reaction followed by amidation with acryloyl chloride using amino group as a linkage to connect oligo(ethylene glycol), N,N -diethylaminoethyl, and polymerizable double bond groups together. Subsequently, the corresponding homopolymers containing oligo(ethylene glycol) unit and N,N -diethylaminoethyl group in each repeated unit were prepared via RAFT polymerization with controlled molecular weights and relatively narrow molecular weight distributions. The lower critical solution temperature (LCST) of homopolymer was examined to be influenced by molecular weight, salt concentration, and pH value of aqueous solution. The LCSTs of homopolymers could be tuned in a wide temperature window by changing pH value of aqueous solution and it increased with the decrease of pH value. Particularly, CO 2 gas as a unique pH stimulus can also reversibly adjust the solubility of homopolymer without the addition of acids or bases.

The little amount of internal double bonds were introduced in poly (butyl acrylate) (PBA) and poly (ethyl acrylate) (PEA) through copolymerizing with isoprene (IP). The tanδ of PBA-co-IP (BA-IP copolymer) and PEA-co-IP (EA-IP copolymer) exhibited an asymmetric double-peak structure with a shoulder at higher temperature side and a maximum at lower temperature side, while the tanδ of PBA and PEA generally displayed single-peak structure. The relaxation spectra showed motion units whose relaxation time were larger than 100 s appeared; so the shoulders were preliminarily determined as the slower processes. The chain-ring assumption was used to analyze this phenomenon. The single bonds that are adjunct to internal double bonds were thought as the “rings” and segments that locate between two neighboring single bonds were thought as the “chains”. Because “rings” single bonds had larger rotation ability than general single bonds, the motions of “chains” between two neighboring “rings” would be improved. Thus, PBA-co-IP and PEA-co-IP displayed asymmetric tanδ curves in mechanical spectra.

A facile pathway for functionalizing carbon dioxide (CO2) derived alicyclic polycarbonates has been developed by the combination of CO2–unsaturated alicyclic epoxide alternating copolymerization and subsequent post-polymerization modification. Thus, poly(cyclohexadiene carbonate) (PCHDC) was synthesized by the alternating copolymerization of CO2 and 1,4-cyclohexadiene-1,2-oxide with tetraphenylporphyrinatocobalt(III) chloride/dimethylaminopyridine. The subsequent post-polymerization modification of PCHDC by bromine addition to double bonds efficiently proceeded to afford the brominated polycarbonate, i.e., poly(dibromocyclohexene carbonate). The effect of post-polymerization modification on their thermal properties was further examined through thermal gravimetric and differential scanning calorimetry analyses.

Crosslinking polymerization has been studied by means of a four-dimensional population balance model accounting for chain length, free pending double bonds, crosslinks, and multiradicals as dimensions. The model, for the first time and to a full extent resolves the crosslinking problem as formulated by Zhu et al. [1] and covers both pre-gel and gel regimes, in a straightforward manner. Approximations on radial basis functions have been employed to reduce the size of the system with minimal information loss. The model has been validated with data from an experimental crosslinking polymerization, Methyl Methacrylate with Ethylene Glycol Dimethacrylate. Non-trivial patterns in the time evolution of average quantities like crosslink densities, partly observed in prior studies [2–4], are naturally emerging from the model by computing marginals of the four-dimensional distribution possessing an interesting multimodal structure.

Long-chain branching (LCB) in polybutadiene (PB) was directly and accurately determined for the first time by combining the hydrogenation of PB with 13C NMR and DEPT spectroscopies. LCB in PB was converted into LCB in polyethylene (PE) by the hydrogenation of PB. No LCB in PE was observed in the 13C NMR spectrum. In contrast, LCB in PE was clearly observed in the 13C DEPT 90° spectrum. The methine carbons in LCB and short-chain branching, which is vinyl branching in PB converted into ethyl branching (EB) in PE, were quantified by 13C NMR and DEPT 90° spectroscopies. The numbers of LCB structures of commercially available PB-A and PB-B were 0.27 and 0.17/1000C, respectively. It was proved that these values were accurate with errors of ca. 10% as determined by analyses of control polymers with various ratios of hexyl branching to EB.

Unsaturated polyester (UP) scaffold, poly (butylene maleate) (P1), possessing an electron-deficient double bond in the main chain was prepared and utilized as a precursor for thiol- and aza-Michael addition reactions. From a detailed catalyst search (amidine and guanidine bases), 1,5,7-triazabicyclo [4.4.0]dec-5-ene (TBD) proved to be the most efficient catalyst for thiol-Michael addition reactions since pendant thioether functional polyesters were achieved quantitatively within 1 min. Furthermore, P1 was allowed to react with primary and secondary amines through aza-Michael addition reactions, followed by thiol-Michael addition reaction thus affording the synthesis of pendant amine and thioether functional polyesters.

Thermally conductive epoxy composite is prepared by directly incorporated graphene into the matrix. The 3-methacryloyloxypropyltriethoxysilane (MPTES) functionalized reduced graphene oxide (MRGO) is synthesized by a sol-gel reaction followed by chemical reduction, leading to the introduction of methacrylate groups with carbon-carbon double bonds. Then, radical copolymerization is employed to afford poly(glycidyl methacrylate) grafted MRGO, which can react with amine groups in the curing agent, 4.4′-diaminodiphenylmethane. The exothermic peaks were observed for the epoxy composites revealed that p-MRGO is co-cured with the curing agent and incorporated into the matrix. The thermal conductivity of the p-MRGO/epoxy composites reaches 0.75 W m−1 K−1 at p-MRGO content of 7 wt%, corresponding to a thermal conductivity enhancement of 249% Furthermore, the crosslinking density is calculated to confirm the co-curing effect of p-MRGO. Our results demonstrated that the covalent bond between the filler and matrix is an advantageous approach for improving the thermal conductivity of epoxy composites.

In this work, we investigated the peculiar peaks found in the MALDI-TOF mass spectra of polystyrenes (PS) with a bromine end prepared by atom transfer radical polymerization when silver trifluoroacetate (AgTFA) and THF were used as cationization agent and solvent, respectively, in the MALDI sample preparation. In the MALDI mass spectrum, PS with a terminal bromine was not detected but the species with a terminal double bond (U series), and −22 m / z (T series) and +18 m / z (W series) peaks relative to U series appeared as major peaks. While the U species was reported as a result of the elimination reaction of HBr, but the origin and the structure of the other species have not been elucidated. We found that the −22 m / z peak of U n is in fact T n -2 , which is the adduct of THF and the anion of the Ag salt, TFA − (+186 m / z ) to U n -2 . The +18 m / z peak was confirmed to be the species with a terminal OH. All these reactions were catalyzed by Ag salt and the T and W series were not found at all when NaTFA was used as a cationization agent.

In the present study, poly[1-methoxy-4-(2′-ethylhexyloxy)- p -phenylenevinylene] (MEH–PPV) was synthesized, modified and characterized by FTIR, NMR, GPC, UV/vis absorption, fluorescence, and mass spectroscopy. The effective conjugation length was controlled by introducing physical and chemical defects into the chain backbone. It was observed that absorption and emission spectra of polymer chains were blue-shifted by importing structural deficiencies. Chemical defects were introduced by controlled oxidation of vinylene double bonds using m -chloroperbenzoic acid and physical defects were induced by tuning polymer–solvent interactions (varying solvent quality). It was shown for the first time that the recorded fluorescence spectrum of MEH–PPV can be reconstructed using the emission data of oligomeric constituents and the contribution of chromophores with different numbers of repeat units to overall emission can be quantified. The effect of excitation energy on the emission pattern was also investigated. It was shown that the emission contribution of shorter chromophores to overall emission is detectable using high excitation energies. Finally, atomistic molecular dynamic (MD) simulation was used to investigate the polymer chain conformation in methanol and chloroform. The results obtained from torsional angles studies confirmed the presence of a great number of induced physical defects in the backbone and, hence, a collapsed conformation of polymer chains in methanol. Evaluations of physical defects along the chain proposed the average number of coplanar phenyl rings of ∼5 and 14 for polymer chains in methanol and chloroform respectively.

In this work, two different polyhedral oligomeric silsesquioxanes (POSS)—octaisobutyl-POSS (OIBS) and allylisobutyl-POSS (AIBS)—were incorporated into poly(methylvinylsiloxane) (VMQ) by melt mixing and then the corresponding blends were chemically crosslinked by peroxide. NMR analysis revealed that AIBS molecules containing double bonds were successfully grafted onto VMQ macromolecular chains during the crosslinking of VMQ. Morphology and thermal stability studies by various methods discovered that the in-situ formation of chemical linking between POSS molecules and VMQ chains could significantly improve the dispersion of POSS particles and the thermal stability of VMQ. For the VMQ with 5 wt% POSS, AIBS exhibited nano-dispersion in VMQ matrix and improved the thermal stability of VMQ, but inert OIBS molecules aggregated extensively to form crystals and adversely affected the thermal stability, although AIBS and OIBS have similar solubility parameters and thermal stabilities. Further studies on the thermal stability of VMQ with different contents of AIBS showed that the thermal stability first increased with increasing content of AIBS but then began to decrease as the content of AIBS exceeded 7.5 wt%. X-ray diffraction and extraction experiments showed that extensive ungrafted AIBS molecules and their aggregates started to appear in the VMQ matrix as the content of AIBS exceeded 7.5 wt%. The study revealed that the grafted POSS hindered the thermal degradation of silicone rubber to cyclic oligomers but the ungrafted POSS favored the thermal degradation.

Poly(butylene fumarate) (PBF) bearing reactive double bonds on the polymer main chains has been designed and synthesized by coupling with hexamethylene diisocyanate (HDI) under very mild condition. The chemical structure, conformational structure, crystal structure and molecular weight of PBF were systematically characterized by ATR-FTIR, 1H NMR, 13C NMR, GPC and WARD. The thermal properties, mechanical properties and biodegradability of PBF were carefully studied by DSC, mechanical testing and enzymatic degradation. The results of 1H NMR and 13C NMR spectra indicate that no isomerization or Ordelt saturation reaction of trans C C took place during the bulk polymerization and the reaction just proceeded in the way we designed. Linear PBF with high-molecular-weight has been successfully synthesized. This new type of uncrosslinked polyester is shown to have many merits such as relatively high melting point (Tm), satisfactory processability and good mechanical properties. The impact strength of PBF is higher than 200 J/m; tensile and flexural strength can reach to 41.0 and 26.7 MPa, respectively.

Pd(dibenzylideneacetone) 2 , when activated in situ with 1 equiv of [CPh 3 ][B(C 6 F 5 ) 4 ] in the presence of 1 equiv of P(C 6 H 11 ) 3 , efficiently catalyzed the addition polymerization and copolymerization of norbornene and its derivatives. Homopolymerization of 5-vinyl-2-norbornene took place regio-selectively with the endo-cyclic double bond to give high-molecular weight polymers, while the exocyclic double bond remained intact so that the resulting polymer had pendent vinyl groups along the polymer chain. In the polymerization of a mixture of the endo -/ exo - isomers of 2-methoxycarbonyl-5-norbornene, the endo -isomer was consumed prior to consumption of the exo -isomer, contrary to the well-known tendency in Pd(II)-based catalyst systems. Another notable feature of the present catalytic system was the strong dependency of the molecular weight on the reaction temperature, which was studied in detail for the copolymerization of 2-methoxycarbonyl-5-norbornene with norbornene: we could control the molecular weight without the use of a chain transfer agent. The extracted oligomeric fraction of poly(norbornene) showed the presence of a terminal CC double bond as well as a C 6 F 5 unit that was bound to the first norbornane unit in the polymer chain.

A novel graft copolymer consisting of poly(n-octylallene-co-styrene) (PALST) as backbone and poly(ɛ-caprolactone) (PCL) as side chains was synthesized with the combination of coordination copolymerization of n-octylallene and styrene and the ring-opening polymerization (ROP) of ɛ-caprolactone. Poly(n-octylallene-co-styrene) (PALST) backbone was prepared from the copolymerization of n-octylallene and styrene with high yield by using the coordination catalyst system composed of bis[N,N-(3,5-di-tert-butylsalicylidene)anilinato]titanium(IV) dichloride (Ti(Salen)2Cl2) and tri-isobutyl aluminum(Al(i-Bu)3). The molar ratio of each segment in the copolymer, and the molecular weight of the copolymer as well as the microstructure of the copolymer could be adjusted by varying the feeding ratio of both styrene and n-octylallene. The hydroxyl functionalized copolymer PALST–OH was prepared by the reaction of mercaptoethanol with the pendant double bond of PALST in the presence of radical initiator azobisisbutyronitrile (AIBN). The target graft copolymer [poly(n-octylallene-co-styrene)-g-polycaprolactone] (PALST-g-PCL) was synthesized through a grafting-from strategy via the ring-opening polymerization using PALST–OH as macroinitiator and Sn(Oct)2 as catalyst. Structures of resulting copolymer were characterized by means of gel permeation chromatography (GPC) with multi-angle laser light scattering (MALLS), 13C NMR, 1H NMR, DSC, polarized optical microscope (POM) and contact angle measurements.

The synthesis of ethylene-co-5,7-dimethylocta-1,6-diene copolymers (CEDMO) with different molar DMO contents has been performed to incorporate double bonds in the lateral and make easier the development of crosslinkings in the resulting polymer material after application of electron-beam irradiation. The gel content as well as a comprehensive evaluation of the changes in the crystalline characteristics have been carried out. Both features are strongly dependent on DMO composition and irradiation doses. Variation in the mechanical response of the different specimens has been checked by microhardness measurements.

Isotactic polypropylene (iPP)–polystyrene (PS) and iPP–poly(methyl methacrylate) (PMMA) multiblock copolymers were synthesized by atom transfer radical coupling (ATRC) of PS–iPP–PS and PMMA–iPP–PMMA triblock copolymers obtained by atom transfer radical polymerization (ATRP) of styrene (St) and methyl methacrylate (MMA), respectively, using α,ω-dibromoisobutyrateoligopropylene (iPP–Br) as a bifunctional macroinitiator. The iPP–Br was prepared by hydroxylation and subsequent esterification of telechelic oligopropylene having terminal vinylidene double bonds at both ends obtained by controlled thermal degradation of iPP. ATRP of St and (meth) acrylic monomers using iPP–Br formed the corresponding triblock copolymers. It was confirmed that the PMMA–iPP–PMMA triblock copolymer was effective as the compatibilizer for the iPP/PMMA blend. An iPP–PS multiblock copolymer ( M n : 25 000 g/mol and M w / M n : 4.1) was prepared by ATRC of PS–iPP–PS triblock copolymer ( M n : 8900 g/mol and M w / M n : 1.3). ATRC with St of PMMA–iPP–PMMA triblock copolymer ( M n : 13 000 g/mol and M w / M n : 1.4) provided an iPP–PMMA multiblock copolymer containing St chains ( M n : 39 000 g/mol and M w / M n : 2.8).

5-Ethylidene-2-norbornene (ENB) polymerization and copolymerization with ethylene (E) catalyzed by constrained geometry catalyst 2-tetramethylcyclopentadienyl-4,6-di-tert-butylphenoxytitanium dichloride (1) were studied in the presence of AliBu3 and Ph3CB(C6F5)4 (TIBA/B). The catalyst system shows moderate activity on the homopolymerization of ENB, and higher activity on the copolymerization of E/ENB under atmospheric pressure of ethylene. 1H NMR analysis indicates that ENB was regioselectively incorporated into the copolymer backbone through the endocyclic double bond, leaving the ethylidene double bond unreacted. The ethylidene group contained in the poly(E-co-ENB) was quantitatively converted to the epoxy group with m-chloroperbenzoic acid, producing functionalized poly(E-co-ENB)s. The parent and functionalized copolymers have been characterized using IR, NMR, DSC, and GPC techniques.

The geometries and electronic properties of five novel co-polymers which are obtained by replacing phenylene ring in poly(p-phenylenevinylene) (PPV) with five different fused heterocycles, as well as their corresponding monomers and co-oligomers, have been studied using DFT method. The dihedral angle, bond length, bond-length alternation, electron density at bond critical points (BCPs), nucleus-independent chemical shift (NICS) and Wiberg bond index (WBI) are analyzed and correlated with conduction properties. The bond length between the C C linkage and the aromatic ring unit in the studied compounds is decreased and the double bond character is increased along with main chain extension. The changes of BCPs, WBIs and NICSs also show that the conjugational degree is increased with main chain extension and the electronic properties of the studied compounds vary systematically with the electron-withdrawing capacity of the fused heterocycles. The changes of NICS also show that the conjugation in central section is stronger than that in outer section. The band structure analysis shows that the energy gaps of the five novel polymers (in the range of 0.17–0.77 eV) are all much lower than that of PPV (1.3 eV). The proposed new coplanar conjugated polymers may be potential conductors.

Two series of high-performance polymer alloys were prepared by mixing typical benzoxine monomers, 3-phenyl-3,4-dihydro-2H-1,3-benzoxazine (P-a) or 6,6-(1-methylethyliden)-bis-(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine) (B-a), with a typical bismaleimide, 4,4-bismaleimidodiphenyl methane by various ratios followed by thermal treatment up to 240 °C. DSC and IR of the alloys were examined to follow the curing reaction. These analyses showed that the obtained polymer alloys are AB co-cross-linked polymer networks through the formation of ether linkage between the hydroxyl group of polybenoxazine and the double bond of bismaleimide. Viscoelastic analysis and softening temperature measurement revealed that the polymer alloys have much higher glass transition temperatures than those of each homopolymer. The thermal stability also increased with the increase of bismaleimide content as evidenced by TGA.

Ordered polybutadiene-diols (LCPBDs) with the comb-like architecture were prepared by radical reaction of a 5-(4-{[4-(octyloxy)phenyl]azo}phenoxy)pentane-1-thiol with double bonds of telechelic HO-terminated polybutadiene (PBD); several polymers with various initial molar ratios of thiol to double bonds of PBD, R0, in the range from 0 to 1 were prepared. DSC, polarizing microscopy, WAXS and dielectric relaxation spectroscopy (DRS) were employed to investigate their thermal and dielectric behavior in relation to morphology. DRS of the LCPBDs have revealed both collective and individual dynamic motions of molecules. Secondary β- and segmental α-relaxation were observed in unmodified PBD. In the LCPBDs, two secondary γ- and β- and two high-temperature α- and δ-relaxations were observed and assigned to specific molecular motions; all relaxations were analyzed and discussed in terms of time scale (Arrhenius diagram), magnitude (relaxation strength) and shape of the response.

Cyclic acetals were used to replace the conventional amines in bimolecular photoinitiating systems. The mixtures of benzophenone derivatives and cyclic acetals were used to initiate the UV photopolymerization of 1,6-hexanedioldiacrylate (HDDA). Camphorquinone (CQ)/1,3-benzodioxole (BDO) combinations were used to initiate the visible light photopolymerization of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (BisGMA)/triethylene glycol dimethacrylate (TEGDMA) (70/30 wt%) for dental application. The kinetics was recorded by real-time infrared spectroscopy (RTIR). Ethyl 4-N,N-dimethylaminobenzoate (EDMAB) was used as control in the same photocuring condition. The results showed that the addition of cyclic acetals greatly increased the rate of polymerization (Rp) and final double bond (DC) of HDDA. Combination of p-chlorobenzophenone (CBP)/BDO had the highest initiating reactivity. BDO also showed an effective coinitiator for camphorquinone-based initiator system. Comparing with EDMAB, CBP/BDO and CQ/BDO indicated comparable initiating reactivity. Moreover, the natural component characteristics of BDO made it a promising alternative to commercial amine in biomolecular photoinitiating system.

The photo-induced copolymerization of dodecyl methacrylate (DDM) with five oxyethylene glycol dimethacrylates (OEGDM) was investigated. Effects of the monomer ratio and of the length of dimethacrylate spacer group on the polymerization kinetics, the extent of the after-effect and pendant double bond content in the polymerization product were studied and the reactivity ratios estimated. For systems containing OEGDM with short spacers between the methacrylate groups, Rpmax reached the highest value at certain monovinyl/divinyl monomer ratio. This phenomenon was discussed in terms of the behavior of the reaction diffusion parameter (as a function of monomer ratio and conversion). Determination of the reactivity ratios by five calculation methods showed that r1 (DDM) values were lower than 1 and the r2 (OEGDM) values were higher than 1 indicating that the polymer formed at the beginning of the reaction is more densely cross-linked than that formed in the final reaction stages.

We performed a detailed comparison of properties of two different styrenic polymers containing divinylbenzene as the crosslinker before and after the introduction of the additional crosslinks by Friedel–Craft's reaction of the residual double bonds. For the polymer characterization was used a wide selection of methods, including nitrogen adsorption/desorption, inverse steric exclusion chromatography, MAS NMR and AFM. The residual double bonds are quite probably located in the dense cores of the microgel domains where steric hindrances prevented them to react during the polymerization. Reinforcement of the cores of polymer microgel domains by transformation of the residual double bonds into additional crosslinks by the Friedel–Craft's reaction results then in greater stability of the already existing pores rather than in creation of new pores by incomplete collapse of swollen polymer gel.

Polymerization of o-diethynylbenzene (1) by Rh and Ta catalysts resulted in the formation of structurally different polymers depending on the kind of catalyst. When a Rh catalyst was used, insoluble cross-linked poly(1) was formed, mainly consisting of alternating double bonds and the unreacted ethynyl group along with indene-type structure formed by intramolecular cyclization as a minor component. A Ta catalyst completely consumed both ethynyl groups in the polymerization of 1 to afford mainly highly cross-linked poly(1) containing trisubstituted benzene unit via intermolecular cyclization. 1-Ethynyl-2-phenylethynylbenzene (2) was polymerized by W and Mo catalysts to give soluble polymers with Mn of 6300–71,900 in good yields. Poly(2) obtained by Mo catalysts had alternating double bonds in the main chain and o-(phenylethynyl)phenyl group as side chains. Poly(2) formed by W catalysts predominantly contained a similar main-chain structure and also possessed the naphthalene-type cyclic unit formed by cyclization of the adjacent diethynyl groups as a minor part.

Holographic polymer dispersed liquid crystals (HPDLCs) are targeted for application in a wide range of devices as dynamically switchable transmission or reflection diffraction gratings tunable through the visible spectra. The inclusion of N-vinyl pyrrolidinone (NVP) has been shown to reduce liquid crystal (LC) droplet size in HPDLC gratings and subsequently improve HPDLC performance. In this work, the influence of NVP on HPDLC polymer/LC morphology is examined and correlated to the influence of NVP on HPDLC photopolymerization kinetics and LC phase separation. As in other photopolymer systems, NVP significantly increases the rate of polymerization in HPDLC photopolymerization. In all the HPDLC formulations studied, NVP is completely incorporated into the polymer network while less than half of acrylate double bonds react. Furthermore, as the highly cross-linked polymer network forms, the small mono-vinyl NVP appears to react preferentially with acrylate double bonds, facilitating additional conversion of pendant double bonds otherwise trapped in the polymer network. NVP also induces a delay in the onset of reaction diffusion termination and extends the range of conversions for which reaction diffusion is observed. Interestingly, NVP also impacts polymer/LC morphology by delaying LC phase separation to higher double bond conversions. Together, the influence of NVP on the polymerization kinetics and LC phase separation alters HPDLC morphology by limiting LC droplet size, consequently resulting in improved HPDLC performance.

Cinnamate polymers are well known photoreactive polymers due to [2+2] cycloaddition reaction of cinnamate side group. In this work, we have found that the cinnamate side groups could be also reacted by thermal energy, and this reaction is presumed to attribute to the radical reaction of carbon double bond in the cinnamate groups. Contrary to the photocycloaddition reaction of the cinnamate side groups, the thermal reaction of cinnamate side group was closely related to the flexibility of polymer backbone. The difference of the mechanism between the photocycloaddition reaction and thermal crosslinking reaction was confirmed by 1 H NMR and 13 C NMR analysis of the model compound.

Recently, we demonstrated that conjugated sequences of unsaturated double bonds can be introduced into co-polymers such as styrene butadiene rubber (SBR), which contains isolated double bonds along the polymer backbone through conjugation reactions induced by iodine [Sreeja R. Submitted for publication [1] ]. Here, we report for the first time the doping reaction in another notable co-polymer nitrile rubber, a co-polymer of acrylonitrile and butadiene. The conductivity reaches a value of about 0.01 S/cm with the characteristic color change from colorless to dark red upon doping. FT-IR and UV/VIS studies of the polymer film establish the formation of conjugated sequences of the unsaturated double bonds followed by the formation of charge transfer complexes with the dopant ion. The reaction is analogous to the iodine doping of SBR for longer doping period and retained flexibility of the film after doping. However, the band gap evaluated is greater for NBR and this increase can be explained as due to the presence of electron withdrawing –CN groups in place of electron releasing phenyl group in the SBR backbone, which can cause a partial influence on the chemical reaction along the polymer backbone. The excellent oil resistance, abrasion resistance and mechanical properties of NBR combined with the newly developed semi conducting behaviour can be utilized for fabricating various electronic and optical devices based on this elastomer.

This work demonstrates the applicability of the free-radical addition of ω-functional mercaptans onto 1,2-polybutadienes as a modular synthetic pathway toward a toolbox of diverse functional block copolymers. Functional groups included, for instance electrolytes (carboxylic acid and amine), l -amino acid, and fluorocarbon. The number of functional groups attached to the polymer was lower than that of double bonds reacted (degree of functionalization=50–85%, typically 70–80%) due to cyclization of two neighboring units, but the narrow molecular-weight distribution of the parent (co)polymer was always maintained.

The polymerization of 7-, 8- and 11-membered lactones, 6-methylene-1,4-oxathiepan-7-one, 3-methylene-1,5-oxathiocan-2-one and 3-methylene-1-oxa-5-thiacycloundecan-2-one in benzene at 70, 40–70 and 40–65 °C, respectively, is presented. All polymerizations proceeded with complete ring-opening up to approximately 25% conversion, where insoluble polymer was formed. Evidence is given attributing polymer double bond loss to crosslinking, although redistribution of the molecular weights via addition to polymer double bonds followed by β-fragmentation also appears to occur for polymerizations of the 8- and 11-membered lactones. Michael adducts of lactones with 2-methyl-2-propanethiol were prepared as models for chain-transfer products of hydrogen abstraction by carbon-centred radicals. Polymerization rates were found to increase marginally with ring size. Arrhenius parameters obtained for the polymerizations of the 8- and 11-membered lactones indicated that the addition step was more important than fragmentation in determining the rate of propagation.

This work describes the synthesis and characterisation of two types of thiophene-containing poly(arylene–ethynylene)-alt-poly(arylene– vinylene)s (PAE–PAV) copolymers, whose repeating units (–Ph–C^C–Th–CHaCH–Ph–CHaCH–)n, 5, and (–Th–C^C–Ph–C^C–Th– CHaCH–Ph–CHaCH–)n, 8a–c, consist, respectively, of a 1:2 and a 2:2 ratio of triple bond/double bond moieties. Comparison of their photophysical, electrochemical and photovoltaic properties has been carried out. Although similar electrochemical data (HOMO: K5.43 eV, LUMO: wK3.15 eV, E ec Z 2:28 eV) as well as identical thin film absorption behaviour (laZ500 nm, E opt g Z 2:10 eV) were obtained for both types of materials, significant differences in their thin film photoluminescence behaviour and photovoltaic properties were observed. While polymer 5 shows a fluorescence maximum at leZ568 nm (with a fluorescence quantum yield of FfZ7%), a total fluorescence quenching was observed in 8. Far better photovoltaic performance was obtained from solar cells (set up: ITO/PEDOT:PSS/active layer/LiF/Al; active layer consisting of 5 or 8b as donor and PCBM as acceptor in a 1:3 ratio by weight) designed from 5 than from 8b. Open circuit voltage, VOC ,a s high as 900 mV and power conversion efficiency, hAM1.5, around 1.2% were obtained. This can be attributed to the 1:2 triple bond/double bond ratio as well as the grafting of shorter octyloxy and 2-ethylhexyloxy side chains in 5 and to its comparatively higher molecular-weight. q 2005 Elsevier Ltd. All rights reserved.

Ene-grafting of maleic anhydride on polypropylene previously enriched in double bonds by beta-scission was promoted in order to obtain model grafted polypropylene. Ene-grafting was carried out in the presence of a radical-scavenger in order to limit at a minimum side-grafting and in presence of catalyst (SnCl2) in order to maximise the ene-grafting. Nevertheless, it does not lead to high grafting content. Ene-grafted PP confirms the single end-grafted succinic anhydride FTIR assignment at 1792 cm(-1) (C=O symmetric stretching) while a disubstitution is also observed leading to a shift to a 1784 cm-1 absorption band. This latter band was more generally assigned to interacting anhydride (C=O) instead of an assignment to the particular polyanhydride species (as previously assigned by our team [De Roover B, Sclavons M, Carlier V, Devaux J, Legras R, Momtaz A. J Polym Sci, Part A: Polym Chem 1995;33:829. [14]]). (c) 2005 Elsevier Ltd. All rights reserved.

A theoretical analysis is presented on the use of semibatch reactors for producing non-linear copolymers through the homogeneous free-radical polymerization of mono- and divinyl-monomers. The kinetic scheme distinguishes two kinds of pendant double bonds and five kinds of polymer radicals, as it also takes into account the primary cyclization of terminal divinyl units. In spite of the fairly large number of groups and reactions, the generating function of vector chain length distribution of polymer species can still be accurately computed by a numerical implementation of the method of characteristics and thus average molecular weights before and after gelation can be reliably obtained. The influence of feed policies of the monomers, initiator and transfer agent on gelation, average chain lengths and weight fraction of sol is discussed, as well as their sensitivity to some kinetic parameters.

A polyhedral oligomeric silsesquioxane containing seven isobutyl groups and one mercaptopropyl group (POSS-SH) was linked via a free radical addition reaction to the side-chain double bonds of bacterial poly[3-hydroxyalkanoate-co-3-hydroxyalkenoate], (PHAE). PHAE with 11.5, 55, 78, and 97 mol% of double bonds were used to produce a series of inorganic–organic hybrid materials, PHAE–POSS, with increasing amounts of POSS. The reactions proceeded with high yields and limited side reactions, confirmed with NMR and GPC experiments. X-ray diffraction and 13C solid-state NMR analysis of these nanocomposite materials suggested the favoured crystallization of POSS, with PHAE functioning as a non-crystalline combining matrix. This is in contrast to blends of POSS-SH and PHAE, where incompatibility occurred and the two components crystallized independently. The covalent links between PHAE and POSS imposed spatial constraint which resulted in disordered crystalline POSS domains and limited crystal sizes. With increasing POSS content, the appearance of these POSS-based biopolyesters changed from non-sticky and elastic to brittle and glass-like. The covalent linking of POSS-SH to PHAE increased the heat stability such as glass transitions, and melting points could be tailored between 48 and 120 °C.

A (star polystyrene)- block -(linear polyisoprene)- block -(star polystyrene) copolymer, (S) n I(S) n , was prepared. The star polystyrene was produced via anionic polymerization of polystyrene macromonomers each containing an unsaturated double bond (vinyl) at the chain end. This vinyl-terminated polystyrene macromonomer (SSTM) was obtained beforehand via the synthesis of a living polystyrene using alkyllithium and the termination with p -chloromethylstyrene (PCMS). The living site in the core of the star polystyrene enabled the construction of the succeeding polyisoprene block resulting in the living (star polystyrene)- block -(linear polyisoprene) copolymer, (S) n I. This living diblock copolymer was then coupled with 1,2-dibromoethane (DBE) to form the well-defined (S) n I(S) n . Compared to a linear polystyrene- block -polyisoprene- block -polystyrene, SIS, with the same molecular weight, (S) n I(S) n had a higher T g and exhibited a lamellae-forming phase separation in conjunction with many dislocation defects. The thermal stability appeared independent of the molecular structure, and the radius of gyration and viscosity of (S) n I(S) n were much smaller than SIS.

This article deals with the estimation of the reactivity of a novel methacrylic macromonomer with amphiphilic character derived from Triton X-100 (MT) in radical copolymerisation reaction with acrylic acid (AA). Two approaches to estimate the reactivity ratio of the macromonomer are described. The first involves the use of the Jaacks equation valid for systems with a large excess of one of the comonomers and leads to rAA=0.31. The second method uses a low molecular weight model monomer (MTm) that reproduces the chemical structure of the macromonomer. A non-linear fitting of the experimental data of the system MTm–AA to an integrated form of the copolymerisation equation which describes the terminal model postulated by Mayo and Lewis, gave reactivity ratio values of rMTm=2.5 and rAA=0.30. The results obtained from the two estimations suggest that methacrylic double bond reactivity is not affected by poly(oxyethylene oxide) chain length. In situ quantitative 1H NMR analysis was used to monitor monomer consumption and therefore to follow the course of the copolymerisation reaction in both approaches.