摘要：随着纳米技术的发展，近年来应用纳米级粒子改性聚合物成为研究热点。由于纳米粒子表面积大,表面能高，因而其对聚合物结晶行为将产生很大影响，并进而影响材料的性能。44108

聚合物的结晶行为与温度及成核剂等因素有关。测定其结晶过程可以推断不同加工条件下高聚物及其复合材料制品在力学、光学等性能上的差异，以及制品在加工和使用中可能产生的变化[1]。

本文概述了单独的HDPE(高密度聚乙烯)和单独的PP（聚丙烯）的聚合物结晶情况，添加了不同质量分数的纳米二氧化硅的PP聚合物的结晶形态。并得到了以下的结果：在相同的结晶温度下，纳米二氧化硅粒子起到了异相成核的作用，其的加入可以使得所形成球晶的平均直径较单独的PP聚合物基体的直径减小；并且可以表现出随着纳米二氧化硅的质量分数的增加，球晶平均直径呈现逐渐减小的状态。

With the development of nanotechnology in recent years, application of nano-sized particles modified polymers become a hot topic. Due to the large surface area of nanoparticles, the surface power can be high, so it will have a significant impact on the crystallization behavior of the polymer, and thus affect the properties of the material.

Polymer crystallization behavior is related with temperature and type of nucleating agent and other factors. After determination of the crystallization process and crystallization ability can be inferred that the differences under different processing conditions and polymer composite products in the mechanical, optical and other properties, as well as products that might arise in the processing and use.

This article outlines the HDPE (high density polyethylene) and the PP (polypropylene)polymer crystallization.Under isothermal conditions，the effects of crystallization morphology of PP polymer when add nano-silica with different mass fraction 。 And got the following results: at the same crystallization temperature, nano silica particles played a role of heterogeneous nucleation;Its entry into PP polymer matrix can make the average diameter of spherulites reduce; and may exhibit with increasing mass fraction of nano-silica, the average diameter of tspherulites showed a gradual decrease of state。

毕业论文关键词：纳米二氧化硅；HDPE基体；PP基体；球晶；

Keyword：nanoparticles; HDPE (high density polyethylene); PP (polypropylene); spherocrystal;

目录

1.前言 4

1.1结晶高分子的结构和形态以及结晶过程的特点 4

1.1.1链的结构对结晶能力的影响 4

1.1.2晶态高分子的形态 4

1.1.3高分子结晶过程的特点 5

1.2 HDPE（高密度聚乙烯）和PP（聚丙烯）； 5

1.2.1  目前高性能聚合物的需求状况[2] 5

1.2.2实现聚合物高性能的途径； 5

1.2.3高密度聚乙烯的性能特点[5] 6

1.2.4聚丙烯(PP)的性能特点： 6

1.3纳米复合材料 7

1.3.1纳米材料： 7

1.3.2纳米二氧化硅 7

1.3.3纳米复合材料的特点： 7

2  纳米SiO₂对PP/HDPE结晶过程的影响 8

2.1实验原料及设备 8

2.1.1实验原料 纳米二氧化硅对PP和HDPE结晶过程的影响:http://www.751com.cn/huaxue/lunwen_45287.html