排斥体积对聚乙烯链形状的影响  

Influence of Excluded Volume on the Shape of Polyethylene Chain

作　　者：陈英才[1] 宋栩冰[2] 罗孟波[3] 许健民[3] 

机构地区：[1]台州师范专科学校物理系,浙江临海317000 [2]浙江大学化学系,浙江杭州310028 [3]浙江大学物理系,浙江杭州310028

出　　处：《科技通报》2000年第1期37-41,共5页Bulletin of Science and Technology

摘　　要：用Monte Carlo 方法对考虑骨架原子排斥体积的聚乙烯链的形状进行了研究. 聚乙烯链短程骨架原子之间的相互作用近似考虑为三级相互作用,长程骨架原子之间的相互作用近似为骨架原子之间存在排斥体积. 考虑骨架原子排斥体积的聚乙烯链,〈L22〉/〈L12〉和〈L32〉/〈L12〉都比不考虑排斥体积的聚乙烯链的〈L22〉/〈L12〉和〈L32〉/〈L12〉大,从链长N= 400 附近外推,长链极限下〈L12〉∶〈L22〉∶〈L32〉的比值约为1∶3.0∶14.5,而不考虑排斥体积的聚乙烯链,其值约为1∶2.7∶12.0.The average instantaneous shape of polyethylene chain with excluded volume was studied with Monte Carlo method. The short range interactions of the chain are considered approximately as third order interactions, while long range interactions are excluded volumes of skeleton atoms. 〈L 2 2〉/〈L 1 2〉 and 〈L 3 2〉/〈L 1 2〉 of polyethylene chain with excluded volumes are much bigger than that of polyethylene chain without excluded volumes. The limit value of the ratio 〈L 1 2〉∶〈L 2 2〉∶〈L 3 2〉 of polyethylene chain with excluded volumes, extrapolated from the datum of chain length around N =400, is about 1∶3.0∶14.5, while that of polyethylene chain without excluded volumes is about 1∶2.7∶12.0. The angle θ between the longest principal axis of inertia of the polyethylene chain with excluded volumes and the end to end vector was also investigated, which statistical average 〈 θ 〉 is about 25° for long chain.

关 键 词：聚乙烯链 排斥体积 MONTECARLO 分子形状 

分 类 号：O632.12[理学—高分子化学] O631.12[理学—化学]