增韧剂的选择与应用
Selection and application of toughening agent
1、CSR核壳橡胶增韧剂主要是由丁苯橡胶或者聚丁二烯橡胶粒子核及丙烯酸外壳组成的，直径是100~200nm，耐温范围是-80℃~400℃，它主要特点是通过调节壳结构化学组成以提高核心结构与基体的相容性。
1, CSR core-shell rubber toughening agent is mainly composed of styrene butadiene rubber or polybutadiene rubber particle core and acrylic case, the diameter is 100~200nm, the temperature resistance range is -80 C ~400 C. Its main feature is to improve the compatibility of core structure and matrix by adjusting the chemical composition of the shell structure.

它的优点是：
Its advantages are:
①在环氧树脂中分散均匀，固化前后CSR同样分散均匀；
The dispersion of CSR in epoxy resin is uniform, and the CSR is also uniform before and after curing.
②不降低固化物的Tg的同时明显提高韧性、耐冲击和剪切强度等性能；
(2) the toughness, impact resistance, shear strength and other properties of the cured product can be obviously improved without decreasing the Tg of the cured product.
③具有极佳的电气性能（杂质含量很低）；
(3) excellent electrical properties (low impurity content);
④CSR的尺寸和品质稳定；
(4) the size and quality of CSR are stable.
⑤透明度高。
(5) high transparency.

2、端羧基丁腈橡胶（CTBN）增韧剂是由丁二烯、丙烯腈和有机酸三元共聚而成。它的优点是粘接强度和剥离强度相对较高；缺点是与环氧树脂的相容性差，容易从树脂中分离出来；由于相分离结构程度不完全，橡胶颗粒在固化物中分散不均匀，这导致固化物Tg的下降明显；粘度大，不易分散；不耐低温，低温（-20℃以下）基本无强度。
2. Carboxyl terminated acrylonitrile butadiene rubber (CTBN) toughening agent is composed of butadiene, acrylonitrile and organic acid three yuan. Its advantage is that the bonding strength and the stripping strength are relatively high; the disadvantage is that the compatibility of the epoxy resin is poor and is easily separated from the resin; because the phase separation structure is not complete, the rubber particles are dispersed inhomogeneous in the curing substance, which leads to the obvious decrease of the Tg of the curing substance; the viscosity is large, it is not easy to disperse; it is low temperature resistant and low. The temperature (below -20 C) is basically no strength.