In the reported experiments, PVC has been cyclopentadienylated by two conventional basic, LiCp and NaCp, and a new acidic, Me//2CpAl, cyclopentadienylating agent. PVCs treated with basic cyclopentadienylating agents undergo severe random dehydrochlorination and exhibit a significant decrease in thermal and thermooxidative stability. In contrast, according to ozonization and degradation experiments, Me//2CpAl does not cause dehydrochlorination during cyclopentadienylation. The thermal stability of PVC treated with relatively high concentrations of Me//2CpAl and Me//3Al at 25 degree C markedly increases due to substitution of labile chlorines in PVC with methyl groups. Acceleration of thermal dehydrochlorination disappears and the length of polyene sequences is reduced on Me//2CpAl and Me//3Al treatment. These observations are attributed to differences in rates of protonation-deprotonation; that is, rates of reinitiation of zipping of treated and untreated PVCs during thermal degradation.
|Number of pages||17|
|Journal||Journal of polymer science. Part A-1, Polymer chemistry|
|Publication status||Published - Jan 1 1981|
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