- 作者: 王文濱
- 作者服務機構: Union Industrial Research Laboraton'es, Industrial Technology Research Institute, Hsinchu, Taiwan, Republic of China
- 中文摘要: Gamma radiation induced polymerization of vinyl chloride (VC) and copoly-merization of vinyl chloride (VC)-vinyl acetate (VAc) in Taiwan cedars have been investigated at low temperatures. The polymerization-rate of VC and the copolymerization-rate of VC-VAc system in wood were found to be proportional to the n powers of the dose-rate , where n became close to the value of 1 as the polymerization temperature being lowered below 0℃. The oxygen in air was recognized to induce the delay of the induction period due to its retardation on the polymerization. The apparent activation energies of VC and VC-VAc for the polymerization and the copolymerization in wood were determined by use of the Arrhenius plotting as 4.0Kcal/mole and 3.4 kcal/mole respectively at the temperature-range of -15℃~20℃. The degree of polymerization (P) of VC was greatly affected by the polymerization temperature, although it was observed to be independent on the total gamma dose within 1 Mrad and the kinds of wood. No graft reaction of PVC polymer and PVC-PVAc copolymer onto the wood cellulose was found, while low graft percentage of about 3% being obtained at 20℃ in the case of using swelling agents. However, this value was found to be decreased to 0.1% at the temperature of -15℃. Based on the above-mentioned experimental results, the radiation induced low temperature polymerization of VC or copolymerization of VC-VAc system in Taiwan produced cedars are considered to proceed with radical polymerization mechanism.
- 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --