摘要
为阐明口罩过滤层聚丙烯(PP)熔喷纤维与熔喷PP塑料的塑化和结晶行为间的差异性,采用差示扫描量热仪(DSC)和热台偏光显微镜系统研究了3种熔喷PP塑料与4种口罩过滤层PP熔喷纤维的塑化和结晶行为。结果表明,PP熔喷塑料试样3显示单峰,PP熔喷纤维试样5呈现3峰,而其余PP熔喷塑料和PP熔喷纤维均呈现双峰;与PP熔喷塑料相比,口罩过滤层PP熔喷纤维的晶体塑化起始温度较低,晶体完全塑化温度区间宽,且偏向低温区方向;PP熔喷塑料试样开始发生结晶的温度较高,口罩过滤层PP熔喷纤维试样开始发生结晶的温度较低,与其晶体塑化起始温度和完全塑化温度偏低一致,这是由于口罩过滤层PP熔喷纤维较大的数均相对分子质量(Mn),使其结晶温度和塑化温度均较高;PP熔喷塑料试样的结晶化温度区间较窄,口罩过滤层PP熔喷纤维试样的结晶化温度区间较宽,表现出不同的结晶形态演变过程,且异相成核过程中晶核的形成和晶体生长均比均相成核过程快。
The plasticization and crystallization behaviors of three types of melt blown PP plastics and four types of PP melt blown fibers for mask filter layer were investigated by DSC and hot stage polarizing microscopy.In the DSC thermograms,the sample 3^# showed a single melting peak,whereas the sample 1^#,sample 2^#,sample 4^#,sample 6^# and sample 7^# revealed a bimodal melting behavior.Moreover,the sample 5# showed three peaks in its DSC thermogram.Compared to the PP melt blown plastic samples,the crystal plasticization of the PP melt blown fabric samples for mask filter layer started at a lower initial temperature with a wider temperature range for completing the plasticizing process.The presence of such a temperature range also shifted to a lower temperature zone.The initial crystallization temperature of the PP melt blown plastic samples was higher than that of the PP melt blown fabric ones.These results are consistent with their crystal plasticization temperatures and plasticization completion temperatures.This may due to the fact that the PP melt blown fabric samples for the mask filter layer have higher number average molecular weights,resulting in higher crystallization and plasticization temperatures.The crystallization temperature range of the PP melt blown plastic samples is narrower than that of the PP melt blown cloth ones for the mask filter layer,indicating different evolution mechanisms in their crystalline morphology.
作者
詹瑾
马晶晶
高达利
李好义
杨卫民
ZHAN Jin;MA Jingjing;GAO Dali;LI Haoyi;YANG Weimin(Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China;Aerospace Research Institute of Materials&Processing Technology,Beijing 100076,China;Sinopec Beijing Research Institute of Chemical Industry,Beijing 100013,China)
出处
《中国塑料》
CAS
CSCD
北大核心
2021年第1期8-12,共5页
China Plastics
基金
国家重点研发计划(2020YFC0844800)。
关键词
聚丙烯
熔喷布
塑化行为
结晶行为
演变机理
polypropylene
melt blown fabric
plasticizing behavior
crystallization behavior
evolution mechanism
