PP相对分子质量及其分布对其单丝结晶及力学性能的影响  

Effect of relative molecular mass and its distribution of PP on crystallization and mechanical properties of monofilament thereof

作　　者：秦维秀 马海燕[1] 成晓燕 QIN Weixiu;MA Haiyan;CHENG Xiaoyan(School of Textile and Clothing,Nantong University,Nantong 226000)

机构地区：[1]南通大学纺织服装学院,江苏南通226000

出　　处：《合成纤维工业》2020年第2期31-36,共6页China Synthetic Fiber Industry

基　　金：国家重点研发计划项目(2016YFB0303100)。

摘　　要：将3种不同熔体流动指数(MFI)的聚丙烯(PP)按一定的质量比通过机械混合均匀,在单螺杆挤出机上纺成直径分别为0.20,0.25,0.30 mm的单丝,研究了PP的MFI与其相对分子质量及其分布之间的关系,以及相对分子质量及其分布对PP结晶行为和力学性能的影响。结果表明:混合后的PP熔体MFI介于两种原料的MFI值之间,且PP的相对分子质量及其分布随着MFI值的变化而变化,MFI越高,PP的相对分子质量越低;随着相对分子质量分布变窄,PP的结晶温度和熔融温度降低,结晶度增大,结晶速度加快;3组混合试样分别在MFI每10 min为3.74,4.80,11.21 g时相对分子质量较小,相对分子质量分布最窄,PP单丝的力学性能达到最佳,且直径为0.20 mm时的PP单丝力学性能最好。Polypropylene(PP) with three different melt flow index(MFI) was mechanically mixed at different mass ratios and was spun into the monofilaments with the diameters of 0. 20,0.25 and 0.30 mm on a single-screw extruder. The relationship between MFI and the relative molecular mass and its distribution of PP was investigated. The influence of the relative molecular mass and its distribution on the crystallization behavior and mechanical properties of PP was also investigated. The results showed that the MFI value of the mixed PP melt was between the MFI values of the two raw materials, and the relative molecular mass and its distribution of PP changed with the MFI value, that is to say, the higher the MFI value, the lower the relative molecular mass of PP;the crystallization temperature and melting temperature of PP decreased, the crystallinity increased and the crystallization rate increased while narrowing the relative molecular mass distribution;and each of the three mixed samples exhibited the relatively low relative molecular mass, the narrowest relative molecular mass distribution and the best mechanical properties of PP monofilament when MFI was 3.74, 4.80 and 11.21 g per 10 min respectively, and the PP monofilament with a diameter of 0.20 mm had the best mechanical properties.

关 键 词：聚丙烯 单纤维 熔体流动指数 相对分子质量 相对分子质量分布 热性能 力学性能 

分 类 号：TQ342.62[化学工程—化纤工业]