超高分子量聚乙烯的稀溶液结晶与形态  

Crystallization and Morphology of Ultra High Molar Mass Polyethylene from Dilute Solutions

作　　者：乐征宇[1] 于瀛[1] 范仲勇[1] 

机构地区：[1]复旦大学材料科学系,上海200433

出　　处：《复旦学报（自然科学版）》2004年第4期663-667,共5页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金重大基础研究资助项目(90103037);教育部博士点基金资助项目

摘　　要：由ρ为10-3～10-5g/mL的稀溶液等温结晶,生长了超高分子量聚乙烯(UHPE)片晶.长达数十万 的UHPE分子链在稀溶液中彼此分离,在RegimeⅢ结晶温区等温结晶过程中,1根分子链能多次成核,生长出多个小片晶,即形成单链多晶.由熔点估算得到片晶的厚度约22nm.形态研究证实了单链多晶的形成.并证实:随着结晶过冷度的增大,UHPE片晶的b轴与a轴方向的尺寸比由3～5降低为1,即由大尺寸的长六边形片晶转变为准六边形的小晶片.Small lamellae of ultra-high molar mass polyethylene were grown through isothermal crystallization from dilute solution with concentration ranged from 10^(-3) to 10^(-5) g/mL. Chains of the UHPE with several 10~5 ? in length could be separated in dilute solution, and one single chain can form several lamellae, i.e. single chain multiple crystals, by multi-nucleation and growth on crystallizations in the regime Ⅲ. By means of DSC, the thermal analysis of the samples indicated that their melting temperature decreased as the solution concentration decreased. Average thickness of lamellae was estimated to be about 22 nm according to the melting points of samples. The study of crystal morphology indicated the formation of single chain multiple crystals. Moreover, it was shown that the ratio of size in the direction of b axis to that in the direction of a axis decreased from 3—5 to 1 with increase of undercooling for crystallization of UHPE dilution solution.

关 键 词：超高分子量聚乙烯 稀溶液 结晶 形态 热分析 

分 类 号：O632.12[理学—高分子化学]