论文总字数：43395字

摘 要

团状模塑料(BMC)在固化成型过程中会发生体积收缩，导致尺寸失控、力学性能降低和表面质量缺陷等问题。在本课题中我们把丁二酸作为新型小分子低收缩添加剂，它不同于常用的的大分子低收缩剂，具备更好的抗收缩效果。实验分两个阶段，第一阶段实验是在BMC样品中加入丁二酸(20%)，调整不同的前酯化反应时间进行前酯化反应，然后通过样品收缩率测试得到最佳前酯化反应时间为3.0 h；然后在最佳前酯化反应时间的前提下将丁二酸的抗收缩效果与大分子低收缩剂的抗收缩效果相比，结果表明丁二酸的抗收缩效果明显好于大分子低收缩剂。第二阶段实验是以CaCO₃含量、玻纤含量以及丁二酸含量为变量的三因素四水平正交实验，分析三个因素对BMC制品的体积收缩率和弯曲强度的影响。实验结果显示对体积收缩率影响最大的因素为CaCO₃含量，而对弯曲强度影响最大的因素为玻纤的含量。综合考虑各因素对BMC试样的体积收缩率和弯曲强度的影响以及在经济效益方面影响，最终得到BMC试样的最佳原料配比为：UPR∶丁二酸∶CaCO₃∶E-玻纤∶TBPB=100∶20∶200∶20∶1。通过差示扫描量热分析(DSC)显示，丁二酸加入后，将UPR的两步聚合过程转变为单一交联聚合，消除了聚酯自聚；魔角旋转核磁共振(HR/MAS NMR)对丁二酸的前酯化反应进行定量分析；扫描电子显微镜(SEM)表明，经过3.0h前酯化反应的固化样品形成了均一的平板式形貌。因此丁二酸对BMC的抗收缩包含两个过程：第一个过程是丁二酸与UPR树脂中过量二元醇的酯化反应，生成了水和热塑性聚酯；第二个过程是抑制UPR树脂的交联聚合，并消除聚酯自聚，从而降低了BMC的固化收缩率。

关键词：团状模塑料(BMC) 丁二酸 前酯化反应 收缩率 弯曲强度

The Application of Succinic Acid in Low-shrinkage

Bulk Molding Compounds

Abstract

Bulk Molding Compound (BMC) in the curing process will occur volume contraction, leading to uncontrolled dimensions, the reduce of mechanical properties, surface quality defects and other problems. In this issue, we use succinic acid as a novel small molecule low shrinkage agents, which is different from the common macromolecular low shrinkage agents, and succinic acid has better anti-shrinkage effect. The experiment was divided into two stages, the first stage was to join the succinic acid(20%)in BMC samples, and adjust different pre-esterification time to conduct the pre-esterification, then we got that the best pre-esterification time was 3 h through the sample shrinkage test; compared to the anti-shrinkage effect of the succinic acid and macromolecular low shrinkage agents under the premise of the best pre-esterification time, the results showed that the anti-shrinkage effect of the succinic acid was obviously better than the anti-shrinkage effect of macromolecular low shrinkage agents. The second stage was the variable orthogonal of three factors and four levels with the contents of CaCO₃, glass fiber and succinic acid, then analyzed the influence of three factors on the volume shrinkage and bending strength of BMC products. The results of experiment showed that the biggest factor for volume shrinkage was the CaCO₃ content, while the biggest factor for the bending strength was the content of glass fiber. Considering the influence of various factors on the volume shrinkage and bending strength of the BMC products and the influence in terms of economic efficiency, we can finally get the best ratio of raw materials of the BMC products: UPR꞉ succinic acid꞉CaCO₃꞉E-Glass fiber꞉ TBPB =100꞉20꞉200꞉20꞉1. Differential scanning calorimetry (DSC) showed adding succinic acid transformed UPR two-step polymerization process into a single cross-linked polymerization process and eliminated the self-polymerization of polyester; pre-esterification of succinic acid was quantitatively analyzed by Magic angle spinning nuclear magnetic resonance (HR/MAS NMR); scanning electron microscopy (SEM) showed cured samples formed a uniform flat topography after 3.0h pre-esterification. Therefore, anti-shrink of succinic acid on the BMC contains two procedures: the first is the esterification of succinic acid with excessive diol in UPR resin, forming the thermoplastic polyester and water; the second is to inhibit UPR resin cross-linked polymerization and to eliminate the self-polymerization of polyester, thus to reduce the curing shrinkage rate of BMC.

Key Words: bulk molding compounds (BMC); succinic acid; pre-esterification reaction; shrinkage; bending strength

目 录

第一章 文献综述

1.1 BMC的简介

BMC（Bulk Molding Compound）是团状模塑料的简称，是在不饱和聚酯树脂（简称UPR，Unsaturated Polyester Resins）的热压成型工艺基础上发展起来的一类重要复合材料品种。BMC主要由不饱和聚酯树脂（UPR）、填料（碳酸钙等无机填料）以及各种添加剂（如固化剂、脱模剂等）经充分混合后浸渍增强纤维加工而成的团状或块状热固性模塑预浸料^[1~2]。因为BMC团状模塑料具有优良的电气性能，机械性能，耐热性，耐化学腐蚀性，而且适应多种成型工艺，满足各种产品对性能的要求，所以被广泛应用于电气部件、汽车部件、建筑、航天军工和电子塑封等领域^[3~7]。

1.1.1 国内外BMC的发展现状

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