超临界聚合法等规聚丙烯的结晶行为  

STUDY ON CRYSTALLIZATION BEHAVIOR OF ISOTACTIC POLYPROPYLENE PRODUCED BY SUPERCRITICAL POLYMERIZATION

作　　者：曹堃[1] 霍志宏[1] 姚臻[1] 王齐[1] 范荣[1] 王兴仁[2] 杨爱武[2] 笪文忠[2] 柏基业[2] 姚小利[2] 尤侯平[2] 

机构地区：[1]浙江大学材料与化工学院高分子工程研究所聚合反应工程国家重点实验室,浙江杭州310027 [2]中国石化扬子石油化工股份有限公司,江苏南京210048

出　　处：《高分子材料科学与工程》2005年第6期110-112,117,共4页Polymer Materials Science & Engineering

基　　金：中石化和教育部科学技术研究重点项目资助(104095)

摘　　要：采用差示扫描量热法及带热台在线偏光显微镜直接观察法,研究了超临界聚合与常规淤浆聚合这两种不同聚合工艺所制备等规聚丙烯的等温结晶行为。结果表明,超临界法聚丙烯(sc-iPP)由于其较低的分子量及较窄的分布,使得等温结晶速率比常规淤浆法聚丙烯(c-iPP)快,结晶度高,且sc-iPP的晶体呈负光性,倾向于异相成核。而c-iPP的晶体则呈混光性,倾向于均相成核,但两者均为典型的球晶,均体现热成核机理。The isotactic polypropylene prepared under the supercritical ：conditions was compared with that obtained by a conventional slurry polymerization with respect to the isothermal crystallization kinetics by Perkin Elmer differential scanning calorimetry （DSC） and Nikon E600 optical polarimeter （OP） with on-line hot stage, respectively. The results indicate that isothermal crystal radius growth rate of supercritical isotactic polypropylene （sc-iPP） with lower molecular weight and narrower its distribution is faster than that of common isotactic polypropylene （c-iPP）. Moreover, crystallinity of sc-iPP is higher than that of c-iPP. The resulting crystals of sc- iPP have negative character and tend heterogeneous nucleation. On the contrary, the obtained crystals of c-iPP present heterozygosis birefringence and prefer homogeneous nucleation. Furthermore, Both sc-iPP and c-iPP are spherulites and show thermal nucleation. Base on these, crystallization activity energy and Avrami exponent of both sc-iPP and c-iPP were calculated, respectively.

关 键 词：超临界聚合 淤浆聚合 等规聚丙烯 结晶 成核 

分 类 号：O631.13[理学—高分子化学]