环氧树脂以其优异的力学、电气性能和耐化学腐蚀性能被广泛地应用于涂料、胶粘剂、浇注料、
包封料及玻璃钢制品。但是单纯的环氧树脂固化后性能较脆，冲击强度和耐热冲击性能较差，为了改善环氧树脂固化物的这一不足之处，通常的方法是在环氧固化体
系中引入增塑剂，如邻苯二甲酸二丁酯(DBP)、磷酸三苯酯(TPP)等。这些材料的引人使环氧固化制品的脆性有所好转，但在固化过程中有从体系中离析的
倾向，造成材料变质和老化。即使不离析出来，其增塑(增韧)效果也有限。新型端羧基丁腈橡胶(CTBN)改性环氧增韧剂是
1种复合高分子材料。在环氧固化体系中引入新型CTBN改性环氧增韧剂，可使环氧树脂在固化过程中离析出来后形成尺寸恰当的分散第2相。
它的存在是环氧树脂得以增韧的关键。在材料破坏时，裂纹的扩展遇到增韧剂分散相颗粒分歧、转向，从而消耗能量并阻止了裂纹变成裂缝，以及裂纹迅速发展使固
化物造成开裂。另外，增韧剂分散相在材料受力时，还能起到调节环氧树脂网络分子发生取向、拉伸、变形、空洞化和诱发产生裂纹等许多耗能过程，使固化物抵抗裂纹的扩展能力提高，增韧剂制品韧性明显增强，固化产物的剪切强度、冲击强度、弯曲强度等性能显著提高，同时使固化产物的刚性和玻璃化温度下降不明显。本文介绍该新型CTBN改性环氧增韧剂的合成及其在环氧树脂固化体系中的应用与功效。
Epoxy resin is widely used in coatings, adhesives, castables,
encapsulation and fiberglass products because of its excellent
mechanical, electrical and chemical corrosion resistance. In order to
improve the deficiency of epoxy resin curing, the usual method is to
introduce plasticizer in epoxy curing system, such as dibutyl phthalate
(DBP), three benzyl phosphate (TPP) and so on. The brittleness of the
epoxy cured products improved by the introduction of these materials,
but the tendency of segregation from the system during the curing
process resulted in the deterioration and aging of the materials. Even
without segregation, its plasticizing (toughening) effect is limited.
The new type of carboxyl terminated nitrile rubber (CTBN) modified epoxy
toughening agent is 1 kinds of composite polymer materials. The
introduction of a new CTBN modified epoxy toughening agent in the epoxy
curing system can make the epoxy resin segregate out of the curing
process and form a suitable second phase. The existence of epoxy resin
is the key to toughening epoxy resin. When the material is destroyed,
the crack extension meets the divergence and turn of the particles in
the dispersed phase of the toughening agent, thus consuming energy and
preventing the crack into cracks, and the rapid development of the crack
causes the cracking to be caused by the crack. In addition, when the
material is subjected to the force of the toughening agent, many energy
dissipation processes can be used to regulate the orientation, tensile,
deformation, cavitation and induced cracks of the epoxy resin network
molecules, which make the solidifying resistance to the crack growth,
the toughness of the toughening agent, the shear strength and the impact
of the cured product. The strength and flexural strength of the cured
products increased significantly, while the rigidity and glass
transition temperature of cured products decreased. This paper
introduces the synthesis of the new CTBN modified epoxy toughening agent
and its application in epoxy resin curing system and its efficacy.
