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作 者:董小芳[1] 任合刚[1,2] 刘智博[1] 段中余[1] 杨敏[1] 石艳红[1] 侯凯湖[1] 刘宾元[1]
机构地区:[1]河北工业大学化工学院高分子材料科学与工程系,天津300130 [2]中国石油天然气股份有限公司大庆化工研究中心,大庆163714
出 处:《高分子学报》2014年第10期1356-1363,共8页Acta Polymerica Sinica
基 金:国家自然科学基金(基金号51373046;21004017);教育部新世纪优秀人才支持计划(项目号NCET-10-0125)资助
摘 要:采用Ziegler-Natta催化剂催化1-丁烯本体聚合,稀土β-成核剂经原位聚合的方法加入到体系,并考察成核剂加入量对产物聚(1-丁烯)的分子量和结晶性能的影响.通过凝胶渗透色谱(GPC)、示差扫描量热仪(DSC)、偏光显微镜(POM)和广角X射线衍射仪(WAXD)对聚合物进行表征分析.实验结果表明,随着稀土β-成核剂加入量的增大,催化剂活性有所下降,聚合物等规度略有提高,而聚合的分子量显著提高,分子量分布变窄;聚合时成核剂的加入提高了聚(1-丁烯)的结晶性能,随着成核剂加入量的增多聚合物晶粒变小且尺寸趋向均一化,聚合物结晶度也得到了提高,当成核剂加入量为30 mg时,聚合物结晶度和熔融焓出现突变现象.此外,稀土β-成核剂的加入会改变熔融前聚(1-丁烯)中晶型Ⅰ'和Ⅲ所占比例从而影响聚合物的熔点,成核剂的存在也改变了晶型II向晶型I的转变速率,缩短了晶型转变周期.Poly(1-butene) was modified with rare earth β-nucleating agents which were introduced in situ during bulk polymerization of 1-butene. The influence of nucleating agent amount on the molecular weight,melting temperature( Tm),degree of crystallinity(χc),and crystallization behavior of resulting poly(1-butene) was investigated in detail by gel permeation chromatography(GPC),differential scanning calorimeter(DSC),polarizing microscopy(POM),and wide angle X-ray diffraction(WAXD). The results show that with the increase of nucleating agent content the isotacticity of poly(1-butene) was slightly increased,the numberaverage molecular weight( Mn) was obviously improved and the molecular weight distribution was narrowed while the activity of Ziegler-Natta catalyst was somewhat decreased. The addition of rare earth β-nucleating agents changed the crystallization behavior of polymers,the spherulite size of nucleated poly( 1-butene)dramatically decreased compared with that of pure poly( 1-butene) and tends to homogenization with the increasing of nucleating agents content,the χcof poly(1-butene) is improved,especially when the addition ofβ-nucleating agents is 300 mg,but dropped dramatically after this point. In addition,the rare earth β-nucleating agents not only play an positive role in improving Tmby changing the proportion of forms Ⅰ’ and Ⅲ,but also speed up the transformation of crystalline form from Ⅱ to Ⅰ,shorten the crystal transformation period.
关 键 词:ZIEGLER-NATTA催化剂 聚(1-丁烯) 稀土β-成核剂 结晶
分 类 号:TQ316.3[化学工程—高聚物工业]
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