Photosensitive polymers of cyclobutane formation type have been found to show a decrease in their refractive indices with progress of photocrosslinking, when studied by the waveguide method. The decrease in refractive index is considered to be due to a decrease of exaltation in molar refraction. This phenomenon is of potential importance in holographic recording.
In order to examine effect of the carbonyl group in carbon monoxide–vinyl chloride copolymer, poly(CO–VC), photoirradiation with a high‐pressure mercury lamp on the copolymer was carried out. Poly(CO–VC) had a rate of dehydrochlorination three times that of PVC, and the reaction involved a decrease in chlorine content. Also there was a marked change in the ultraviolet spectra of the photoirradiated films. However, no pronounced change of molecular weight was observed, but a change in Rf in TLC was observed clearly. These facts confirmed that photoirradiation of poly(CO–VC) produced a structural change by dehydrochlorination without serious decrease of molecular weight. In addition, photodehydrochlorination of the copolymer or PVC film was followed kinetically, and after ozonolysis of the dehydrochlorinated polymers, the number‐average molecular weights were measured. From the results of degree of dehydrochlorination and molecular weight, the number average of conjugated double bonds or carbonyl groups was estimated. A mechanism for dehydrochlorination process by photo‐irradiation is suggested.
Polymethylhydrosiloxane was added to the Ziegler catalyst in propylene polymerization, and a kinetic study carried out for this system was in good agreement with the results obtained in the polymerization carried out in an autoclave under pressure. The experimental equations for polymerization rate are
for constant siloxane and AlEt3 concentrations and
for constant siloxane and TiCl4 concentrations, where α, A, and β are constants. From experimental results of studies of the chemical properties of polymethylhydrosiloxane, a reasonable reaction mechanism was proposed which can explain the experimental results in the polymerization process. The polymers were separated by use of several solvents, and both the residue and extracted parts showed the presence of silicon. On the basis of chemical analysis and infrared absorption spectra, it was concluded that the polymers obtained were copolymers of polypropylene and polymethylsiloxane.
New routes for copolymerization of carbon monoxide with styrene or vinyl chloride were found by emulsion polymerization (nonionic or ionic emulsifier). These procedures yielded copolymers containing carbonyl groups even at high conversion. These carbonyl‐containing polyketones were photoirradiated in solvent. In carbon monoxide—styrene copolymer of high molecular weight, the viscosity change produced by photoirradiation was especially remarkable, while in carbon monoxide—vinyl chloride copolymer no pronounced change in viscosity was observed, even at high contents of carbonyl group.
synopsisThe system comprising the ethoxydized product of triethylaluminum, cuprous chloride, and carbon tetrachloride was used as an initiator for polymerization of vinyl chloride, and the polymerization kinetics was studied. From plots of the molar number of number-average polymer chain Y/p versus yield Y, the two parameters a ( =JR,dt -1/*JR&) and b (=JR,&/JR,&) were estimated to be 6 X mole/l. and 6.6 X lo-' respectively. Studies of the tacticity of the poly(viny1 chloride) showed isotactic =49.3% and syndiotactic = 50.7%. The present initiator also permitted mpolymerization of vinyl chloride with carbon monoxide; the monomer reactivity ratios were n = 0.40 (vinyl chloride) and rs = 0.01 (carbon monoxide).
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