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The effect of polymer chain structure on the optical and electrical properties are reported for poly(4-diphenylaminostyrene) (PDAS), which was prepared by the living anionic polymerization of 4-diphenylaminostyrene (DAS) with the benzyllithium (BzLi)/ N , N , N ′, N ′-tetramethylethylenediamine (TMEDA) system. The optical properties of PDAS are strongly affected by the stereoregularity of the PDAS polymer chain; intramolecular excimer-forming fluorescence was observed from PDAS with a syndiotactic-rich configuration. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of PDAS were approximately −5.4 and −2.0 eV, respectively, regardless of the polymer chain structure. The hole and electron drift mobilities for PDAS were in the order of 10 −4 to 10 −5 (cm 2 /V s) and 10 −5 (cm 2 /V s), respectively, with negative slopes. The distance of each triphenylamino (TPA) group in the polymer chain was a major factor influencing the drift mobility of PDAS. The current–voltage ( I – V ) characteristics of PDAS were controllable according to the polymer chain structure of PDAS.

Physical vapor deposition polymerization was achieved by evaporating vinyl monomers followed by heat treatment. This technique was utilized for preparing a hole-transport layer (HTL) and emissive layers (EMLs) of organic light emitting diodes (OLEDs). Adivinyl derivative of tetraphenyldiaminobiphenyl, DvTPD, was used both for the HTL and for the host material of red phosphorescent EML. A vinyl derivative of bis(N-carbazolyl)benzene, vmCP, was used for the host material of blue phosphorescent EML. The ELMs were doped with red or blue-emitting phosphorescent iridium complexes modified with styril units. After characterizing the devices that have single EML of red or blue emission, an OLED having multilayered ELM was prepared by stacking these layers to achieve quasi-white emission. It was found that the deposition polymerization was effective to improve the emission efficiency. The improvement appeared to be related to the proper carrier balance in the EML.

The grafting reaction of poly( N -vinylcarbazolyl)lithium (PNVCLi) with tert -butyllithium onto fullerene-C 60 (C 60 ) was examined to explore the possibility of preparing new materials for effective photovoltaic cells. When the molar ratio of C 60 /Li was over four, the grafting reaction products obtained were completely soluble in tetrahydrofuran. The number-average molecular weight of the grafting reaction products obtained was greater than that of the respective parent PNVCs, indicating the formation of PNVC with a C 60 end-group. Gel permeation chromatography and 13 C NMR analyses showed that the product of the grafting reaction was C 60 bonded to PNVC and t -butyl groups. UV/vis and PL spectra suggested that this PNVC may be useful for preparing effective photovoltaic cells.

N-butyl-N,N-diphenylamine (BDPA) and N-4-butylphenyl-N,N-diphenylamine (BTPA) were polymerized by oxidation polymerization using iron (III) chloride as oxidant. BDPA showed higher polymerizability. Poly(BDPA) and poly(BTPA) showed UV absorption maximum at 362 and 373 nm. Oxidation potential of poly(BDPA) was 1.02 V versus Ag/AgCl, while that of poly(BTPA) was 1.12 V. Hole mobility of poly(BDPA) was 4.93 × 10−5 cm2/Vs and that of poly(BTPA) was 2.89 × 10−5 cm2/Vs at the electric field of 35 V/μm. The differences of the properties were explained by the higher electron donating power of alkyl group than phenyl group and conjugation of phenyl ring. It was found that both poly(BDPA) and poly(BTPA) can be used as hole transporting material for electroluminescent device.

A new electroluminescent polymer was prepared by oxidative coupling copolymerization of N -(4- n -butylphenyl)phenoxazine (PPX) and 9,9-di- n -butylfluorene (DBF) using iron(III) chloride. The obtained polymers were soluble in common organic solvents and had number-average molecular weight as high as 10,000. The UV–vis absorption maximum and photoluminescence peak shifted to longer wavelengths with the increase of PPX content. The increase of PPX content also caused increase of hole mobility and decrease of electron mobility. A simple single-layer light-emitting-diode device having a structure of indium tin oxide/polymer/Ca/Al was fabricated. The polymer containing 30% of PPX unit showed highest electroluminescent properties with a maximum luminance of 1084 cd/m 2 at 15.5 V operating voltage.

Hole transport polymers consisting of 4-methoxytriphenylamine (P-MOTPA) and 4- n -butyltriphenylamine (P-BTPA) were synthesized by oxidative coupling reaction using FeCl 3 as an oxidant. These polymers had good solubility and their thin films showed sufficient morphological stability. 1 H NMR and 13 C NMR revealed that the monomers were exclusively connected at the p -positions of unsubstituted phenyl groups. Polymers had UV absorption maximum around 370 nm. Cyclic voltammograms of polymers showed well-defined pairs of reduction and oxidation peaks at 1.1 V versus Ag/AgCl, indicating that the polymers are electrochemically active. P-MOTPA and P-BTPA had hole drift mobility of being 4.04 × 10 −5 and 2.98 × 10 −5 cm 2 /V s at the electric field of 50 V/μm, respectively.

The optical and electrical characteristics of soluble polyphenylene (PPH) homopolymers obtained by the complete dehydrogenation of poly(1,3-cyclohexadiene) (PCHD) are reported for the first time. The optical properties were strongly affected by the molar ratios of 1,2-/1,4-phenylene (Ph) units. The HOMO and LUMO energy levels were approximately −5.2 and −2.0 eV, and the microstructure did not influence those energy levels or the band gap energies. The generation of carriers (both electron and hole) in the polymer films was observed, and the drift mobility of electrons and holes was affected by the molar ratios of 1,2-/1,4-Ph units in the polymer chain. The drift mobility of electrons in PPH homopolymers with a high content of 1,4-Ph units was in the order of 10 −4 to 10 −5 (cm 2 /Vs). The I – V characteristics of soluble PPH homopolymers were controllable by the microstructure of PPH. The 1,2-Ph unit imparted appropriate solubility and toughness to the PPH homopolymers.

We report a concept of organic molecular charge dopant in organic-inorganic composites and study its effect on the composite conductivity. Thin film composites are prepared from a 1:1 dispersion of TiO2 or other metal oxide particles in a polymer binder. Introduction of a small percentage of triphenylamine (TPA) derivative dopants increases the dark conductivity by up to five orders of magnitude. This phenomenon is explained in terms of electron donation by the dopant to a continuous network of aggregated metal oxide particles.

Novel light-emitting copolymers containing 4-n-butyltriphenylamine and either anthracene, diphenylanthracene or perylene units were synthesized by polycondensation of two types of dibromides in the presence of bis(1,5-cyclooctadiene)nickel(0). The structure and incorporation ratio of the copolymers were determined by 1 H NMR analysis. From the results of yield and molecular weight measured by gel permeation chromatography, the reactivity of arene units with the 4-n-butyltriphenylamine unit shows decreasing tendency in the order diphenylanthracene>anthracene>perylene. The results of ionization potential measurement reveal that the copolymers have not only hole transporting ability but also electron transporting ability. Single-layer electroluminescent devices were fabricated using these copolymers as a charge transporting and light emitting layer.

A new concept of inorganic nanoparticle dopant into organic hole transporting materials (HTM) is proposed for the design of semiconducting composites. Composites consisting of HTM and TiO2 nanoparticles were prepared using a polymer as a matrix. TiO2 nanoparticles were prepared by sol–gel method starting from titanium tetraisopropoxide. The particle size of TiO2 ranged from 2 to 5 nm. It was found that electrons were transferred from HTM to TiO2, leaving holes in HTM. The composites showed semiconducting characteristics with the conductivity on the order of 10−8 S/cm. A device consisting of ITO/composite/Al showed rectifying ability. The number of the holes was approximately one per 7×105 molecules of N,N,N′,N′-tetraphenylbenzidine (TPD) for the composite consisting of polycarbonate, TPD and TiO2 with the weight ratio of 100:100:3.

Semiconducting nanocomposite was prepared from tetraphenylbenzidine (TPD) and titanium oxide using polycarbonate as a binder. Titanium oxide was prepared by sol–gel process in the presence of binder and TPD. The conductance of the composite reached ca. 3×10 −8 S/cm with the titanium oxide content of 3% of TPD. The film containing only TPD or titanium oxide had conductivity lower than 10 −13 S/cm.

Two esters of succinic acid containing a thioxanthene unit as an electron-transporting moiety and a 4-dicyanovinylaniline (THEH-DCVA) or 4-nitrovinylaniline unit (THEH-NVA) as an electro-optically (EO) active chromophore were successfully synthesized. The obtained succinates form stable amorphous films at room temperature. These compounds have absorption coefficients of 6.7 and 21.5 cm −1 at 633 nm and glass transition temperatures of 11 and 14 °C for THEH-DCVA and THEH-NVA, respectively. Optical absorption is due to electric charge transfer interaction between an electron-accepting thioxanthene moiety and an electron-donating EO active chromophore. The synthesized compounds without photosensitizers, a plasticizer, and polymer binder showed photorefractivity. A large coupling gain (140 cm −1 at 93 V/μm) was observed for THEH-NVA.

The self-diffusion coefficients ( D ) of long cyclic paraffin C 24 H 48 with two transitions at 29 and 51 °C as observed in the DSC diagram are successfully measured within the temperature range from 30 to 70 °C by means of pulse field-gradient spin-echo 1 H NMR method, in order to elucidate the diffusional behavior of the paraffin in the mesophase in the range of 29–51 °C and in the isotropic liquid phase above 51 °C. From the experimental results, it was found that the D value increased with increase in temperature and there is an abrupt turn in the temperature dependence for the mesophase and isotropic liquid phase in the diffusion process.

High molecular weight poly(4-alkyltriphenylamine) was synthesized by chemical oxidation polymerization. 13 C NMR spectra of the obtained polymers revealed that coupling reaction occurred exclusively at the para -position of unsubstituted N -phenyl rings. Poly(4- n -butyltriphenylamine) (P- n BTPA) showed better solubility and processability than polymers prepared from 4-methyltriphenylamine (MTPA) and 4- t -butyltriphenylamine ( t BTPA) because of the high molecular weight and the flexible long n -butyl group in the side chain. Thus, P- n BTPA allows us to prepare the film from its solution in organic solvent with ease. The rigid structure of polymeric backbone affords high glass transition temperature of 182 °C, indicating high thermal stability. Extended conjugation over polymer chain results in red shift of UV absorption up to 375 nm and low ionization potential compared to monomer. The results of the ionization potential measurement and the redox behavior suggest that the polymer has great potential as a hole-transporting material (HTM). The drift mobility of P- n BTPA measured by a standard time-of-flight (TOF) method was found to be of the order of 10 −5 cm 2 /(V s). The results of the photoconductivity measurement revealed that the photoconductivity of P- n BTPA showed much higher than that of poly( N -vinylcarbazole).

N,N′-bis(4-alkylphenyl)-N,N′-diphenylbenzidine (alkyl-TPD) was reacted with 1,4-bischloromethylbenzene, 9,10-bischloromethylanthracene (BCA), 4,4′-bis(chloromethyl)-1,1′-biphenyl (BCP) or 2,7-bis(bromomethyl)-9,9-di-n-butylfluorene (BBF) by condensation polymerization using Friedel–Crafts reaction. The polymers were obtained in high yield and high molecular weight. TPD having two methyl substituents showed higher reactivity and larger gel content than one having two butyl substituents. The structure of polymers was determined by 1 H NMR spectroscopy. It was found that all polymers showing two methylene signals arises from benzyl proton, which indicates that the polymerization occurred not only at the para-position of phenyl group but also at the meta-position of alkylphenyl group in TPD derivatives. All polymers had almost the same oxidation potential as that of TPD itself. The polymer containing anthracene unit showed not only oxidation but also reduction peak.

A new acrylate bearing N,N′-diphenyl-N,N′-bis(4-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine (TPD) was synthesized to apply for hole transport layer of an electroluminescent (EL) device. The thin film of this monomer was fabricated with physical vapor deposition. The obtained thin film was preliminarily irradiated with UV light and then heated up to 400 K in vacuum. The resulting polymer film, 60 nm thick, which had a polymer conversion of 96% had a smooth surface. This even surface could be maintained up to the heating of 420 K. These processes of deposition and polymerization were monitored with in situ reflection infrared spectroscopy. The EL device made of polymer thin film had three times higher efficiency than that from the monomer thin film.

A novel bifunctional chromophore was synthesized by using tolyldiphenylamine (TDPA) and N -(4-nitrophenyl)-piperidine (NPP) units as a hole transporting and a second-order nonlinear optical (NLO) materials, respectively. The chromophore was reacted with paraformaldehyde (FA) using p -toluenesulfonic acid as a catalyst to prepare a main-chain polymer for single component photorefractive (PR) materials. This polymer was mixed with C 60 (charge generating agents) and tricrecyl phosphate (plasticizer) to provide PR devices. The device showed a high photoconductive (PC) sensitivity of 10 −9 cm Ω −1 W −1 and the response time of 4 ms by a four-wave mixing (FWM) measurements at an applied electric field of 80 V/μm using writing intensity of 150 mW/cm 2 , which is the fastest value reported for the organic PR device to date. PR composites consisting of hole transporting polymer showed shorter response times than one consisting of the low molecular weight chromophore.

Acrylate and methacrylate type monomers containing thioxanthene derivative were synthesized and radically polymerized to yield electron transporting polymers. The obtained polymers are soluble in common solvents such as tetrahydrofuran (THF), chloroform, dimethylformamide (DMF). Cyclic voltammograms of all polymers showed two well-defined pairs of reduction and oxidation peaks indicating that polymers are electrochemically active. The polymers with dicyanomethylated thioxanthene derivative were more easily reduced than those with unmodified one because of the strong electron-withdrawing effect of dicyanomethyl groups, while the latter showed higher electron drift mobility than the former. Drift mobility was discussed in relation to the structure of the lowest unoccupied molecular orbital (LUMO) and the electron distribution. A well-balanced distribution of electrons plays an important role for a high-mobility material.

A thin film of triphenylaminemethylacrylate was fabricated by physical vapor deposition onto an indium–tin oxide substrate over a temperature range from 230 to 290 K. This thin film was subsequently polymerized by UV irradiation in vacuum with the aim of fabricating electroluminescent devices. Polymerization of the thin film in vacuum was investigated by in-situ FT–IR reflection absorption spectroscopy. UV irradiation achieved a polymer conversion of around 100%. Though the polymerization time increased at the lower temperature of the substrate, the surface flatness of the thin film was improved. The polymerization mechanism was elucidated as a simple radical polymerization on the basis of the order of monomer consumption rate. The number-average molecular weight increased with decreasing UV intensity.

We report a study on the differences in red-shifted excimer band in photoluminescence (PL) and electroluminescence (EL) spectra of thin films of a copolymer of dibutylfluorene and butylphenylphenoxazine. The relative intensity of the excimer band in PL spectra increases with temperature above the polymer glass transition, and with the intensity of the excitation light. In EL spectra, on the other hand, the relative excimer intensity is seen to decrease with increasing driving voltage. These opposite trends originate from the different nature of excitations in PL and EL spectra: photoexcitation directly creates singlet excitons while electric excitation proceeds via interaction of injected electrons and holes. In case of electric excitation, the observed results might be due to trap-assisted excimer formation.

Triphenylamine derivatives, such as 4-tolyldiphenylamine (TDPA) and N , N ′-diphenyl- N , N ′-di-(4-methylphenyl)-1,4-phenylenediamine (PDA), were reacted with paraformaldehyde (FA) using p -toluenesulfonic acid catalyst to yield linear polymers. 1 H -NMR and 13 C -NMR spectra revealed that FA reacted exclusively at the p -position of triphenylamine derivatives, and TDPA and PDA units were linked not only by a methylene linkage but also by a methylene ether linkage. The PDA–FA polymer contained higher amount of methylene linkage as compared to TDPA—FA polymer. Additionally, the number of methylene ether linkage was increased with the concentration of paraformaldehyde. The glass transition temperatures of PDA–FA and TDPA–FA were at 204°C and 111°C, respectively. These polymers were soluble in conventional solvents such as chloroform, toluene, etc., and showed sufficient morphological stability after the film formation. The hole drift mobility of PDA–FA was found to be in the order of 10 −6 cm 2 /V s.

Three types of oligo(ethylene glycol) dimethacrylate were polymerized by seed polymerization. The gel beads so prepared had a narrow size distribution and were macroporous. The columns packed with gel beads were suitable for aqueous size-exclusion chromatography for polysaccharides, proteins and other hydrophilic polymers. The hydrophilicity of the gel beads was almost equal to that of 2-hydroxyethyl methacrylate-ethylene dimethacrylate copolymer beads which are usually used for aqueous size-exclusion chromatography.

Monodisperse styrene-divinylbenzene gel beads in the range of 4.1–7.5 μm were prepared via a single-step swelling and polymerization method. The seed particles prepared by dispersion polymerization exhibited good absorption of the monomer phase. The resulting gel beads were evaluated as packing materials for gel permeation chromatographic columns. The pressure resistance of gel beads prepared with a volume ratio of diluent to monomers of unity was higher than 120 kg/cm2, and it decreased with the relative amount of diluent. The pore size tended to decrease with decrease in the swelling ratio of the seed polymer. The median pore size in a swollen state was controllable in the range 30–550 A.

Organosilicon polymers which contain thiophene and benzene, benzene derivatives, anthraquinone or anthanthrone units in the main chain were synthesized. The conformation of the polymer was changed by the kind of unit introduced. The characteristic n-doping property and electrochromic phenomena were observed for the polymers with anthraquinone or anthanthrone units due to their carbonyl group, while the other polymers did not show any reversible electroactivity in the p- or n-doping process. The redox potential of the polymer with an anthanthrone unit was higher than that of the polymer with an anthraquinone unit.

Variable-temperature 13C CP/MAS spectra of cyclohexatriacontane (C36H72) in the solid state over a wide range of temperatures were measured, in order to study the phase transition and conformational change of the molecule with temperature. The signals associated with the constrained gauche conformations clearly appear in the spectra at temperatures below 0°C. A new peak at about 30.3 ppm is observed in the 13C CP/MAS spectrum at 0°C. The relative intensity of this peak increases gradually and the other signals become broad with an increase in temperature. This indicates the existence of the “pseudorotator phase” in which C36H72 is undergoing fast conformational interconversion before the melting transition.

Summary form only given. It is well known that fluorenone derivatives have good electron transport ability due to low LUMO. However, low molecular weight compounds have poor mechanical properties and they easily crystallize and decrease the electron transport ability. We have prepared a new polymer having fluorenone units on the side chain- poly(4-vinylbenzyl 9-dicyanomethylenefluorene-4-carboxylate) and measured electrical porperties. The momomer was prepared from 9-dicyanomethylenefluorene-4-carboxylic acid and p-chloromethyl styene, and was polymerized by conventional radical polymerization in solution. Polymer was obtained with 61% yield and as a yellow powder. The polymer was soluble in organic solvent such as THF, chloroform and methylchloride. The number average molecular weight was determined to be 8,200 by GPC using a calibration curve of standard polystylene. The structures of the resulting polymer were confirmed by /sup 1/H-, /sup 13/C-NMR and IR spectra. Polymer in THF solution showed a UV absorption maximum(/spl lambda/max) at 351.25nm. The polymer film showed two reversible redox potentials at -0.51V,-1.04V(oxidation) and -0.62V,-1.15V(reduction). Further detailed studies will be presented at the poster session.

Preparation de copolymeres de composition et de masse moleculaire differentes. Utilisation d'un melange CH 2 Cl 2 -CH 3 (n) pour eluant et d'un gel de polystyrene comme phase stationnaire. Etude de l'influence de la masse moleculaire des copolymeres sur la separation: elargissement des pics par diminution de la masse moleculaire. Temps de retention augmentant avec la teneur en styrene

High-resolution 13C nuclear magnetic resonance (n.m.r.) spectra of melt-quenched polyethylene and polyethylene single crystals are measured by the cross-polarization/magic angle spinning technique. Melt-quenched polyethylene and polyethylene single crystals have four small upfield peaks, a shoulder on the main peak and three small peaks, respectively. Based on the 13C n.m.r. resonance lines of cyclic paraffin C64H128 reported previously, it is concluded that the main peak and the three upfield peaks arise from the trans zigzag structure region and the folded structure region, respectively. From these peak intensities, it is estimated that the stem length of polyethylene single crystals is approximately 125 A. Taking into account an error in the estimation of the small peak intensities, the calculated stem length of 125 A is consistent with the crystal thickness (120–150 A) observed directly by electron microscopy. It can be concluded, therefore, that polyethylene single crystals mainly contain sharply folded structure. Melt-quenched polyethylene may contain sharply folded structure to some extent in addition to loose loops.

High-resolution 13C NMR spectra of cyclic paraffins, n-paraffins and polyethylene in the solid state have been measured by the cross polarization—magic angle spinning technique. It is shown that the 13C chemical shift of the main peak for the trans-zigzag inner methylene carbons of paraffins with the orthorhombic form appears at about 1 ppm further upfield than that with the triclinic form. This difference was theoretically verified to be caused by a local difference in intermolecular interactions in the orthorhombic nad triclinic forms, based on the tight-binding molecular orbital calculation within the CNDO/2 framework.

Stearyl methacrylate (SMA) was copolymerized with ethylene dimethacrylate (EDMA) in ratios of 1:4 to 4:1 by conventional suspension polymerization in w

Gas-phase 1 H NMR spectra of 1,2-dichloropropane (1,2-DCP) and 1,2-di(methoxy- d 3 )-propane (1,2-DMP) have been measured. The conformational energies of these molecules in the gas phase were determined from the observed coupling constants under a three rotational isomeric state model and are compared with the theoretical values from MM2 molecular mechanics and MNDO molecular orbital calculations. The results indicate that gas-phase NMR is useful method for the determination of conformational energies of relatively complex molecules, and that the MNDO results are more reasonable than the MM2 results for molecules containing electronegative atoms such as oxygen.

The 13 C-n.m.r. spectra of geraniol, nerol, four isomers of farnesol and eight isomers of geranylgeraniol were investigated as low molecular weight homologues of polyprenol. The aliphatic carbon signals were assigned by considering the correlation of chemical shifts between these compounds. The C-1 methylene carbona tom in trans units exhibited four signals around 39 ppm reflecting the cis - tran s, cis - tran s (α), tran s- tran s and tran s- tran s (α) linkages. The C-1 methylene carbon atom is cis units showed two signals around 32 ppm reflecting cis - cis and cis - cis linkages. Here, the θ terminal unit showed the same shielding effect as the trans unit on the subsequent unit. The geometric isomerism of the unit linked to the θ terminal unit was distinguished by the chemical shift of the C-1 methyl and C-4 methylene carbon signals. The geometric isomerism of the α terminal unit was determined from the chemical shift of the C-4 CH 2 OH carbon signal. These correlations were independent of the molecular weight of polyprenol homologues.

The geometric isomers of geranylgeraniol were prepared by isomerization of trans,trans,trans -geranylgeraniol by UV irradiation in the presence of thiobenzoic acid. The resulting isomers were separated by high-performance liquid chromatography on styrene-divinylbenzene gel as the stationary phase. The mixture of eight isomers was separated into two fractions according to the geometric isomerism of the hydroxylated terminal unit using 2,2,4-trimethylpentane as the eluent. Each fraction was further separated into four fractions in methanol as the eluent. The isomers were identified by 13 C NMR spectroscopy. Pure cis,cis,cis -, cis,trans,trans -, trans,cis,cis -, trans,cis,trans - and trans,trans,trans -geranylgeraniols were obtained together with three other isomers in 75–87% purity.

The dynamic process of intramolecular excimer formation in meso and racemic 6,8-diphenyltridecanes (PS2), diastereoisomeric dimer model systems for polystyrene, was investigated by using picosecond pulse radiolysis. Monomeric flourescence of meso PS2 was found to decay with time constants of 3.5 and 0.5 ns.

High-resolution 13 C n.m.r. spectra of melt-quenched polyethylene sample were measured within the temperature range of - 120 to 90°C by means of variable temperature/magic angle spinning technique. Based on these results, the temperature change of polyethylene structure in the solid state was discussed.

Recently 13C NMR spectroscopy has been successfully applied to investigate the sequence distribution of 1,2- and 1,4-units or cis-1,4- and trans-1,4-units in polybutadienes. As for polyisoprenes, however, few investigations have been made on the sequence distribution of isomeric structures using this technique, although Duch and Grant have assigned the 13C NMR signals of cis-1,4- and trans-l,4-homopolyisoprenes. In previous work we have found new signals attributed to cis-trans linkages in the 13C NMR spectra of cis-trans isomerized polyisoprenes and assigned the signals using diad sequences of cis-1,4- and trans-l,4-units. We have also studied the 13C NMR spectra of hydrogenated polyisoprenes containing various amounts of 1,4- and 3,4-units and the sequence distribution of 1,4- and 3,4-units were discussed for n-BuLi-catalyzed polyisoprenes. In this work we have investigated the sequence distribution of chicle polyisoprene and cis-trans isomerized 1,4-polyisoprenes containing various ratios of cis-1,4- and trans-1,4-units.

The time-averaged 1 H n.m.r. spectra of ethylene-propylene-dicyclopentadiene, ethylene-propylene-ethylidene norbornene and isobutylene-isoprene copolymers were measured. Assignments of the olefinic resonances were carried out by comparing the spectra with those of each homopolymer and strarting monomers. The concentration of the olefinic unit in copolymer was determined by measuring the intensity ratio between the olefinic proton signal and the signal of trichloroethylene which was added as an internal standard of intensity measurements. The concentrations of unsaturation in copolymers determined by using the iodine-mercuric acetate method were proportional to those determined by the n.m.r. method. The accuracy and precision of the n.m.r. measurements were shown to be better than 10% for a mixture of polyisobutylene and polyisoprene containing 1.24 mol % of unsaturation as a model compound of isobutylene-isoprene copolymer.

The 13C-n.m.r. spectra of polyisoprenes were investigated. Polyisoprenes were prepared with n-Buli Et 2 O , radical (emulsion polymerization), and Alfin catalysts. Poly(isoprene-4,4-d2)s were also prepared with n-BuLi Et 2 O catalysts for the signal assignments. 13C-n.m.r. signals were assigned for dyad or triad sequences of cis-1,4-, trans-1,4-, and 3,4- units. Signals due to head-to-head (4,1-1,4) and tail-to-tail (1,4-4,1) linkages were also assigned. On the basis of signal assignments it was revealed that cis-1,4-, trans-1,4-, and 3,4-units were distributed almost randomly in n-BuLi Et 2 O catalysed polyisoprenes. It was confirmed that radical and Alfin polyisoprenes contained about 15% of each of head-to-head and tail-to-tail linkages. It was found that radical polyisoprene had cis-1,4- and trans-1,4-units distributed randomly along the polymer chain regardless of the head and tail arrangements.

Sequence distribution of styrene-butadiene copolymer (SBR) was investigated by ozonolysis-g.p.c. All the double bonds of butadiene units in SBR were cleaved by ozonolysis in methylene chloride at −30°C, followed by reduction degradation to alcohol with lithium aluminium hydride. The g.p.c. of the ozonolysis products observed with a u.v.-detector showed the peaks corresponding to styrene sequences and styrene-1,2 sequences. Hot- and cold-emulsion SBR samples contained short sequences consisting of 1 to 4 styrene units and 1,2 styrene units respectively. The average sequence length of cold-emulsion SBR was slightly longer than that of hot-emulsion SBR. A partial block SBR prepared by solution polymerization contained short styrene sequences of 1 to 5 units and long sequences having a broad distribution of M w M n = 1.6 with the maximum around 35 units. The styrene sequences containing the 1,2 unit was scarcely observed in this sample.

High resolution 13 C.N.M.R. spectra of cyclic paraffins of long chain lengths up to the carbon number 200 in the crystalline state have been measured by the cross polarization-magic angle spinning technique. It is found that 13 C chemical shift of the main peak for the trans zigzag methylene carbons of cyclic paraffins having the carbon number from 36 to 80 (triclinic form) appears at about 1 p.p.m. further downfield than those having the carbon number from 128 to 200 (orthorhombic form). Such a difference of about 1 p.p.m. is caused by a local change in intermolecular interactions which result in going from the orthorhombic to the triclinic form.