论文总字数：16304字

摘 要

本课题采用片状无机填料-金云母对聚合物材料进行改性，主要是对聚丙烯进行增强增韧改性，改善聚合物的热性能和机械性能。具体方法是采用庚二酸处理的金云母与用庚二酸/氢氧化钙复合处理的金云母，并对处理前后的金云母分别进行了红外光谱分析；将处理金云母加入到聚丙烯基体中，通过双螺杆挤出机进行复合材料的制备，将粒料进行注塑样条，对样条做机械性能、热性能和结晶性能测试。

结果表明，与纯聚丙烯材料相比，金云母/聚丙烯复合材料的缺口冲击强度、弯曲模量、热变形温度和结晶峰温度都得到提高，而拉伸强度和收缩率下降。处理金云母改性聚丙烯比未处理金云母复合材料的综合性能好。当金云母含量达到15%时，弯曲模量和热变形温度有显著提升而收缩率明显下降；金云母是刚性粒子且具有高温稳定性，是其弯曲模量和热变形温度提升而收缩率下降的原因。当庚二酸/氢氧化钙处理过云母的含量达到2.5%时，冲击强度是纯聚丙烯的2.7倍。金云母在复合材料中起到异相成核的效果，且用庚二酸/氢氧化钙处理过的云母更容易使PP中产生β晶，是其冲击强度和结晶峰温度提高的原因。

关键词：聚丙烯 庚二酸 云母 力学性能 热性能

Investigation of Polypropylene/Mica Composites

ABSTRACT

In this paper, the polymer material is modified by flaky inorganic filler-phlogopite, which is mainly used to strengthen and toughen polypropylene (PP) and to improve the thermal and mechanical properties. The method comprises the following steps: the phlogopite was treated with pimelic acid or pimelic acid/ Ca(OH)₂ mixture; the untreated and treated phlogopites were characterized by FTIR. Then they were added into the PP matrix by a twin-screw extruder. Pellets were injected into the specimens to investigate the mechanical, thermal and crystallization properties.

The results show that the notched impact strength, flexural modulus, heat distortion temperature and crystallization peak temperature of phlogopite/PP composites are improved, while the tensile strength and shrinkage are decreased in comparison with the pure PP. The overall performance of treated phlogopite composite is better than the untreated one. When the content of mica is 15 wt%, the flexural modulus and heat distortion temperature are significantly improved and the shrinkage rate is decreased obviously. The phlogopite is a rigid particle and has high stability at high temperature, which is the reason why the flexural modulus and the heat distortion temperature increase and the shrinkage decreases. The impact strength of the composite is 2.7 times greater than that of pure PP when 2.5% phlogopite treated with pimelic acid/Ca(OH)₂ is used. Phlogopite has the effect of heterogeneous nucleation in the composite, and pimelic acid/ Ca(OH)₂ treatment of mica is more likely to produce β crystals in PP, that is the reason of the improved impact strength and crystallization peak temperature.

Key words: Polypropylene; pimelic acid; mica; mechanical properties; thermal properties

目录

摘要 I

ABSTRACT II

第一章 绪论 1

1.1 聚丙烯的晶体结构 1

1.2 聚丙烯的物理改性方法 1

1.2.1 填充改性 1

1.2.2 共混改性 3

1.3 云母的概述 3

1.3.1 云母的种类及应用 3

1.3.2云母表面改性的方法 3

1.4 云母/聚丙烯复合材料的发展现状 4

第二章 实验部分 5

2.1 实验主要原料 5

2.2 实验设备 5

2.3制备试样 6

2.3.1 云母改性处理 6

2.3.2制备云母/聚丙烯复合材料样条 6

2.3.3制备等温结晶样片 6

2.4 性能测试与结构表征 6

2.4.1 傅立叶变换红外光谱（FTIR）分析 6

2.4.2 力学性能测试 7

2.4.3差示扫描量热法（DSC）测试 7

2.4.4耐热性能测试 7

2.4.5 收缩率测量 7

第三章 结果与讨论 8

3.1 FTIR分析 8

3.2 DSC分析 9

3.3力学性能 13

3.4耐热性能 15

3.5收缩率 16

第四章 结论 17

参考文献 18

致谢 18

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