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A new diacid containing optically active functional groups, N,N′-(4,4′-diphthaloyl)-bis-L-leucine diacid (3), was synthesized and used in a preparation of a series of poly(amide-imide)s (PAIs) by direct polycondensation with various aromatic diamines in N-methyl-2-pyrrolidinone (NMP). All polymers derived from diacid (3) were highly organosoluble in the solvents like N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, γ-butyrolactone, cyclohexanone, and chloroform at room temperature or upon heating. Inherent viscosities of the PAIs were found to range between 0.34 and 0.61·dL g−1. All the PAIs afforded flexible and tough films. The glass-transition temperatures of these PAIs were recorded between 212 and 237°C by differential scanning calorimetry, and the 10% weight loss temperatures were ranging from 372 to 393°C and 336–372°C under nitrogen and air, respectively. The polyimide films had a tensile strength in the range of 63–88 MPa and a tensile modulus in the range of 1.2–1.7 GPa. Optically active PAIs exhibited specific rotations in the range of −10.58° to −38.70°. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Cyclization of deproteinized natural rubber (DPNR) or purified natural rubber latex was effectively performed in latex phase by using trimethylsilyl-trifluoromethane sulfonate or trimethylsilyl triflate (TMSOTF) as a novel catalyst, which is still not reported in the case of natural rubber latex. Various cyclization conditions affecting the degree of cyclization were studied, such as dry rubber contents, temperature, TMSOTF concentrations, and time. The cyclized products were characterized by FTIR, Raman, 1H-, and 13C-NMR spectroscopies, as well as DSC and TGA. The degree of cyclization was estimated by 1H-NMR spectrum. It was found that the degree of cyclization in NR was a function of cyclization conditions. The thermal stability of cyclized DPNR increased with the degree of cyclization. Solubility of the obtained rubber was good in chloroform, toluene, cyclohexanone, and cyclohexane, and bad in tetrahydrofuran. The average number molecular weight of cyclized DPNR with 76% degree of cyclization was about 4.2 × 104 g/mol. On the basis of FTIR, Raman, 1H-, and 13C-NMR, the CC of cyclized DPNR dramatically decreased after prolonged reaction time. In addition, the topology of cyclization DPNR particles was rough on its rubber particle as analyzed by TEM. The mechanism for this reaction will also be discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007.

A series of polymer–clay nanocomposite (PCN) materials that consist of organosoluble polyimide and layered montmorillonite clay were prepared by the solution dispersion technique. The organosoluble polyimide containing non-coplanar moiety in diamine monomer and flexible bridging linkages in dianhydride monomer was synthesized by chemical imidization. The as-synthesized PCN materials were characterized by infrared spectroscopy, wide-angle powder X-ray diffraction, and transmission electron microscopy. The organosoluble polyimide showed better corrosion resistance compared to polyaniline, poly(o-ethoxyaniline) and poly(methyl methacrylate) by using a series of standard electrochemical corrosion measurements of corrosion potential, polarization resistance, and corrosion current in 5 wt % aqueous NaCl electrolyte. Polyimide–clay nanocomposite materials incorporated with low loading of clay were found to further improve corrosion inhibition over pure polyimide. Effects of the material composition on the O2/H2O molecular permeability, optical clarity, and thermal properties of polyimide–clay nanocomposite materials were studied by molecular permeability analysis, UV–visible transmission spectra, thermogravimetric analysis, and differential scanning calorimetry, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3573–3582, 2004

A new diimide–diacid chloride (3) containing a noncoplanar 2,2′-dimethyl-4,4′-biphenylene unit was synthesized by treating 2,2′-dimethyl-4,4′-diamino-biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester-imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(ester-imide)s were found to range between 0.31 and 0.35 dL g−1. All of the poly(ester-imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N,N-dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, m-cresol, o-chlorophenol, and chloroform. The polymers showed glass-transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester-imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2486–2493, 2004

A series of polymer–clay nanocomposite (PCN) materials consisting of 1,4-bis(4-aminophenoxy)-2-tert-butylbenzene–4,4′-oxydiphthalic anhydride (BATB–ODPA) polyimide (PI) and layered montmorillonite (MMT) clay were successfully prepared by an in situ polymerization reaction through thermal imidization up to 300°C. The synthesized PCN materials were subsequently characterized by Fourier-Transform infrared (FTIR) spectroscopy, wide-angle powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effects of material composition on thermal stability, mechanical strength, molecular permeability and optical clarity of bulk PI and PCN materials in the form of membranes were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), molecular permeability analysis (GPA) and ultraviolet-visible (UV/VIS) transmission spectra, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1072–1079, 2004

The separation of aqueous alcohol mixtures was carried out by use of a series of novel aromatic polyamide membranes. The aromatic polyamides were prepared by the direct polycondensation of 2,2′-dimethyl-4,4′-bis(aminophenoxyl)biphenyl (DBAPB) with various aromatic diacids, such as terephthalic acid (TPAc), 5-tert-butylisophthalic acid (TBPAc), and 4,4′-hexafluoroisopropylidenedibenzoic acid (FDAc). The pervaporation and evapomeation performance of these novel aromatic polyamide membranes for dehydrating aqueous alcohol solution were investigated. The solubility of ethanol in the aromatic polyamide membranes is higher than that of water, but the diffusivity of water through the membrane is higher than that of ethanol. The effect of diffusion selectivity on the membrane separation performances plays an important role in the evapomeation process. Compared with pervaporation, evapomeation effectively increases the permselectivity of water. Moreover, the effect of aromatic diacids on the polymer chain packing density, pervaporation, and evapomeation performance were investigated. It was found that the permeation rate could be increased by introduction of a bulky group into the polymer backbone. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2688–2697, 2003

Surface modification of argon plasma–pretreated low-density polyethylene (LDPE) film via UV-induced graft copolymerization with a fluorescent monomer, (pyrenyl)methyl methacrylate (Py)MMA, was carried out. The chemical composition and morphology of the (Py)MMA-graft-copolymerized LDPE [(Py)MMA-g-LDPE] surfaces were characterized, respectively, by X-ray photoelectron spectroscopy (XPS) and by atomic force microscopy (AFM). The concentration of the surface-grafted (Py)MMA polymer increased with Ar plasma pretreatment time and UV graft copolymerization time. The photophysical properties of the (Py)MMA-g-LDPE surfaces were measured by fluorescence spectroscopy. After graft copolymerization with the fluorescent monomer, the surface of the LDPE film was found to have incorporated new and unique functionalities. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1526–1534, 2001

A simple technique of thermal graft copolymerization of 1-vinyl imidazole (VIDZ) on pristine and argon plasma pretreated fluorinated polyimide (FPI) films with simultaneous lamination of copper foils was demonstrated. The simultaneous thermal grafting and lamination process was carried out in the temperature range of 80–140°C under atmospheric conditions and in the complete absence of a polymerization initiator. Three different FPI samples of different chemical structures were employed in the present study. An optimum T-peel strength about 15 N/cm was achieved for the copper/FPI laminate. The adhesion strength, however, decreased with increasing fluorine content in the FPI film. The onset of cohesive failure occurred in the FPI film for assemblies with T-peel strength greater than 6 N/cm. The T-peel strengths are reported as a function of the argon plasma pretreatment time of the FPI films and thermal lamination temperature. The adhesion strengths were compared to that of the similarly prepared copper/polyimide (Kapton HN) laminate. Time-dependent water contact angle (Θ) measurements indicated that the surfaces of FPI films are significantly more hydrophobic and more resistant to water diffusion or hydration than the Kapton HN films. The surface compositions of the pristine FPI films, as well as the delaminated FPI films and copper foils were studied by X-ray photoelectron spectroscopy. The thickness of the graft VIDZ polymer layer was in the order of 200 nm, as derived from the cross-sectional view of the scanning electron micrograph. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1478–1489, 1999

Surface thermal graft copolymerization with concurrent lamination was carried out between two argon plasma-pretreated polytetrafluoroethylene (PTFE) films in the presence of aqueous zwitterionic solutions of N,N-dimethyl-N-methacrylamidopropyl-N-(3-sulfopropyl)ammonium betain (DMASAB), N,N-dimethyl(methacryloylethyl)ammonium propansulfonate (DMAPS), and 1-(3-sulfopropyl)-2-vinylpyridinium betaine (SVPB), as well as an aqueous ionic solution of potassium-2-sulfopropylacrylate (SPA) and potassium-2-sulfopropyl methacrylate (SPM), under atmospheric conditions and in the complete absence of an added initiator and system degassing. The lap shear adhesion strength between the PTFE films from simultaneous grafting and lamination depended on the argon plasma pretreatment time of PTFE films, the thermal lamination temperature, the concentration of the monomer solution, and the ionic nature of the grafted chains. Lap shear adhesion strength greater than 120 N/cm2 and exceeding the yield strength of the PTFE substrate used could be readily obtained in most PTFE/zwitterion/PTFE assemblies after simultaneous thermal graft copolymerization and lamination. The chemical compositions of the graft-copolymerized surfaces were studied by X-ray photoelectron spectroscopy (XPS). © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 816–824, 1999

A poly(o-trimethylsilylphenylacetylene) [poly(o-TMSPA)] initiated by a tungsten carbene complex was investigated under various conditions. The molar mass of poly(o-TMSPA) increases with increasing the polymerization temperature and decreasing the initiator concentration. The X-ray diffraction measurements show that poly(o-TMSPA) has an amorphous structure. The water molecules preferentially permeate through the poly(o-TMSPA) membranes. The effects of feed compositions, degree of swelling, and the molecular size of alcohols on the pervaporation performances were investigated. The separation factor and the permeation rate increase with increasing ethanol concentration in the feed. The diffusivity contributes to a major part to selective transport. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 647–654, 1999

A novel bismaleimide, 2,2′-dimethyl-4,4′-bis(4-maleimidophenoxy)biphenyl, containing noncoplanar 2,2′-dimethylbiphenylene and flexible ether units in the polymer backbone was synthesized from 2,2′-dimethyl-4,4′-bis(4-aminophenoxy)biphenyl with maleic anhydride. The bismaleimide was reacted with 11 diamines using m-cresol as a solvent and glacial acetic acid as a catalyst to produce novel polyaspartimides. Polymers were identified by elemental analysis and infrared spectroscopy, and characterized by solubility test, X-ray diffraction, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis). The inherent viscosities of the polymers varied from 0.22 to 0.48 dL g−1 in concentration of 1.0 g dL−1 of N,N-dimethylformamide. All polymers are soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, pyridine, m-cresol, and tetrahydrofuran. The polymers, except PASI-4, had moderate glass transition temperature in the range of 188°–226°C and good thermo-oxidative stability, losing 10% mass in the range of 375°–426°C in air and 357°–415°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 279–286, 1999

Polyurethane elastomers based on polyols such as polycaprolactone diol of molar mass 2000 and polytetramethylene glycol of molar mass 2000; diisocyanantes such as diphenyl methane 4,4′ diisocyanate and dicyclohexyl methane 4,4′ diisocyanate; and chain extenders such as bisphenol-A, bisphenol-S,bisphenol-AF, and their brominated derivatives were synthesized. The effects of polyol, diisocyanate, and chain extender on the physical and thermal properties were also studied. The polyurethane elastomers were investigated by X-ray diffraction (XRD), differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. Their limiting oxygen indexes (LOIs), solubilities, tensile strengths, hardnesses, and elongations were also determined. XRD analyses revealed that all of the polyurethanes were semicrystalline. However, the addition of bromine atoms in the polyurethanes markedly decreased their degrees of crystallinity. The brominated polyurethane elastomers have good flame retardancy, as indicated by large LOIs. All of the unbrominated polyurethanes showed good mechanical properties and high thermal stabilities. Polyurethanes based on bisphenol-S had lower solvent resistance caused by the dipolar nature of sulfonyl groups in the polymer chains. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1251–1265, 1997

This article describes the syntheses of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with 3,3',5,5'-tetrabromobisphenol AF (TBPAF) in a chlorinated hydrocarbon solvent under low-temperature conditions. The new polyphosphates obtained were characterized by infrared, 13 C and 31 P NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, limiting oxygen index, contact angle, and molar mass measurement. All of the polyphosphates obtained had high yields, and the inherent viscosities were in the range 0.12-0.15 dL g -1 . All of the polymers start degrading between 210 and 267°C and had 14-26% residual mass at 700°C in nitrogen. Polymer E, having a methoxy group in the side chain phenyl ring, showed better thermal stability than the other polymers. The X-ray diffraction patterns revealed that all of the polyphosphates were amorphous. These polyphosphates had glass transition temperatures between 140 and 154°C. Polymers obtained from TBPAF had excellent flame retardency, as indicated by high limiting oxygen index values in the range of 63-68. The water contact angles (θ w ) of all of the polyphosphates were in the range of 74-87°. The contact angles of polymers A and B were larger than those of other polyphosphates that contain more oxygen (polymers C and E) or bromine atoms (polymer D).

A novel siloxane-containing diamine, bis(p-aminophenoxy)methylphenylsilane (BAMPS), was synthesized from the condensation of dichloromethylphenylsilane with p-aminophenol in the presence of triethylamine. A series of BAMPS-based aromatic polyimides were prepared from BAMPS and various aromatic tetracarboxylic dianhydrides by the usual two-step procedure including ring-opening polyaddition to poly(amic acid)s and subsequent cyclodehydration to polyimides. The inherent viscosities of poly(amic acid)s III a -III f ranged from 0.09 to 0.36 dL g -1 in N,N-dimethylacetamide at a concentration of 0.5 g dL -1 at 30°C. The inherent viscosities of polyimides were between 0.06 and 0.32 dL g -1 in various solvents at 30°C. Polyimides, especially IV e and IV f , were soluble in a wide range of organic solvents such as N-methyl-2-pyrrolidinone, concentrated H 2 SO 4 , N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide. The polyimides were characterized by elementary analysis, IR spectra, TGA, and DSC. They also had glass transition temperatures ranging from 128 to 181°C. The 10% mass loss temperature was recorded in the range of 404-443°C in nitrogen and of 315-339°C in oxygen.

Aromatic and brominated aromatic homopolycarbonates were synthesized by the two-phase phase-transfer-catalyzed polycondensation of bisphenols with trichloromethyl chloroformate at 25°C. The infrared spectra, inherent viscosity, x-ray diffraction, solubility, contact angle, differential scanning calorimetry, thermogravimetric analysis, and limiting oxygen index (LOI) of all polycarbonates were measured. Polycarbonates of moderate or large molar mass with inherent viscosities up to 0.77 dL/g were obtained in high yields with tetrabutylammonium bromide (TBAB) as a catalyst, sodium hydroxide as a base, and 1,2-dichloroethane as solvent. The brominated polycarbonates have good flame retardency, as indicated by LOI values. The x-ray diffraction diagram showed that all polycarbonates were semicrystalline. The polycarbonate (PC-2) based on bisphenol S has greater crystallinity than the others because of the sulfonyl group, which has a small van der Waals radius. The incorporation of the bromine atoms (PC-4-PC-6) on the ring decreased the crystallinity. Almost all polymers were soluble in DMF, pyridine, and phenol, but insoluble in acetone and m-cresol. Solubility increased remarkably with bromine substitution. The contact angles of polycarbonates (PC-1-PC-3) lie in the of range 82 to 97 degrees greater than that of brominated polycarbonates (PC-4-PC-6). The wettability of the homopolycarbonate based on bisphenol S is greater than that of polycarbonates derived from bisphenol A and bisphenol AF. Tg of polycarbonates lies in the range 141–206°C, although Tg of polycarbonate based on bisphenol S was not detected. Tg of brominated polycarbonates was remarkably greater than that of unbrominated polycarbonates. These polymers obtained from aromatic bisphenols lost no mass below 341°C, but 10% loss of mass was recorded above 396°C in nitrogen. © 1997 John Wiley & Sons, Inc.

A new silane-containing diamine, bis(p-aminophenoxy)diphenylsilane (BAPPS) (I), was prepared by the condensation of p-aminophenol with dichlorodiphenylsilane. A series of silane-containing aromatic polyamides was prepared by the direct polycondensation of BAPPS with various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone using triphenyl phosphite and pyridine as condensing agents. The polymers were examined by 13 C-NMR (nuclear magnetic resonance), infrared (IR) spectra, inherent viscosity, X-ray diffraction, solubility, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The diffraction diagram revealed that polyamides were crystalline or semicrystalline. Almost all of the polyamides were soluble in dimethyl sulfoxide (DMSO), but insoluble in tetrahydrofuran (THF) solvent. The polyamides had glass transition temperatures in the range of 143-194°C.

Phosphorus-containing polyurethanes (PU-P) based on bisphenol-AF were synthesized by N-alkylation in a two-step process. First, the polymer was metalated with sodium hydride ; then the prepared urethane polyanion was treated with diethyl 2-bromoethyl phosphate. IR spectra exhibited characteristic absorptions at 1303 cm -1 (P=O stretch), 1015 cm -1 (PO - C stretch), 960 cm -1 (POC - C stretch), 812 cm -1 (P -O -O deform), 2912-3020 cm -1 (CH stretch), 1646 cm -1 (C=O stretch), 1231 cm -1 (CNH), and 1053 cm -1 (CO-O-C stretch). In the 1 H-NMR spectrum of the maximum substituted PU-P, the signal of the urethane proton (NH-CO-O) at 9.87 ppm virtually disappeared as expected ; new signals appeared at 1.20-1.24 ppm (POCH 2 CH 3 ) and 3.79 ppm (POCH 2 CH 3 ). Physical and thermal properties of the N-alkylated polymer were also investigated with differential scanning calorimetry (DSC), solubility, X-ray diffraction, thermogravimetric analysis (TGA), limiting oxygen index (LOI), and reduced viscosity. DSC analysis showed that T g values were decreased from 81 to 43°C. The reduced viscosities of the PU-Ps were observed in the range of 0.23-0.18 dL g -1 . The results of TGA revealed that the thermal stability was decreased, because the phosphorus moiety in the PUs is readily dissociated thermally. The PU-Ps exhibited enhanced fire resistance because phosphorus simultaneously promoted carbonization of the polymer and inhibited combustion. The X-ray diffraction patterns of the PU-Ps showed that with increasing phosphorus content, the degree of crystallinity of the PUs decreased. N-alkylated PUs are soluble, not only in polar solvents such as N,N-di-methylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, and H 2 SO 4 , but also in less polar solvents such as phenol, toluene, THF, and trichloroethylene.

The dilute solution properties of a cationic polyelectrolyte, poly(dimethyl sulfate quaternized dimethylaminoethyl methacrylate) [poly(DMAEM · C2H6SO4)], are studied by measurements of intrinsic viscosity, degree of binding, and flocculation application. The intrinsic viscosity of this polyelectrolyte is related to the type and concentration of added salt. The intrinsic viscosity behavior for cationic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. The polyelectrolyte in the presence of KCl has a lower degree of binding, indicating that the proton ion (H+) is relatively difficult to bind to the CH3SO4− at the polymer end. The polymerization of DMAEM · C2H6SO4 in 0.5M KCl aqueous solution proceeded more easily than that of DMAEM · C2H6SO4 in pure water. The polymerization rate of DMAEM · C2H6SO4 is found to pass through an extreme value as a function of pH. Optimum flocculation, corresponding to the complete removal of turbidity in the supernatant, is achieved. Beyond the optimum flocculation, high polymer dosages redisperse the bentonite suspensions.

The free radical grafting of cyclohexyl methacrylate (CMA) onto 1,2-polybutadiene (1,2-PBD) in benzene solution at 60°C was studied. The graft copolymer was characterized by IR, NMR, DSC, and intrinsic viscosity measurements. The polymerization of CMA shows normal kinetic behavior when the PBD concentration is kept below 1.0 monomer mol/L. The rate of grafting was determined at different reaction times, monomer concentrations, initiator concentrations, backbone concentrations, temperatures, and concentrations of the zinc chloride additive. The performance of the graft copolymer used as adhesive was also investigated for bonding of PVC/PVC film.

The aqueous solution properties of an ampholytic poly[3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate] [poly(DMAPS)] are studied by measurements of cloud point determination, intrinsic viscosity, degree of binding, and ionic strength. The minimum salt concentration and intrinsic viscosity of this polyampholyte are related to the type and concentration of added salt. Both the polymeric and monomeric betaines in the presence of NaCl have the lower degree of binding, indicating that the proton ion (H+) is relatively difficult to bind the SO−3 at the end of sulfobetaine. An increase in ionic strength causes the pKa to decrease at the half-neutralization point.

The thermal degradation of poly[3-dimethyl (methylmethacryloyl)ammonium propanesulfonate], [poly(DMAPS)], was studied under nitrogen and air atmosphere at various heating rates. The kinetic parameters such as activation energy, preexponential factor, and reaction order were determined by Ozawa's method. Thermal degradation of such polymer occurs in two and three stages in nitrogen and air atmosphere, respectively. Larger sample weights produce a larger temperature interval (ΔT), but the weight loss (ΔW) between the temperature of the start and the end of degradation is approximately independent of the sample weights.