摘要
采用差示扫描量热法与广角X射线衍射研究了聚丙烯(PP)的结晶形态,考察了结晶温度、外加成核剂、PP熔体流动速率和无规共聚PP中乙烯单体含量等对PP结晶形态的影响。运用PP结晶过程γ晶型与α晶型的共结晶相图,从本质上解释了结晶温度、乙烯单体含量及成核剂对PP结晶形态的影响。结果发现,PP结晶过程可以产生γ晶型,随着结晶温度的升高、成核剂含量和PP中乙烯单体含量的增加、PP熔体流动速率的增大,γ晶型含量增加。质量分数为0.1%的成核剂使PP中γ晶型的质量分数增加了15.6%;成核剂含量进一步增加,γ晶型含量增加变缓;当成核剂质量分散为0.4%时,γ晶型质量分数仅增加了近16.3%。
This paper studied the crystalline morphology of polypropylene (PP) with differential scanning calorimetry (DSC) and wide angle X-ray diffractometry (WAXD) and furthermore, examined the influences of crystallization temperature, addition of nucleating agent, melt flow rate of PP and ethylene monomer content in random copolymer of propylene on the crystalline morphology of PP. A substantial explanation for the dependence of crystalline morphology on those effective factors was derived from application of the co-crystallization phase diagram of α- and γ-modification in the crystallization process of PP. The experimental results indicate that γ-modification can be generated in the crystallization process of PP and its content rises with increasing the crystallization temperature, content of nucleating agent and ethylene monomer and melt follow rate of PP. When mass fraction of the nucleating agent reaches 0.1%, the mass fraction of γ-modification in the PP is raised by 15.6%. However, γ-modification content goes up moderately in case of further adding the nucleating agent, for instance, after adding 0.4% mass fraction of the nucleating agent, the mass fraction of γ-modification is increased by only about 16.3%.
出处
《合成树脂及塑料》
EI
CAS
北大核心
2005年第2期14-18,共5页
China Synthetic Resin and Plastics
