增韧剂对灌封胶力学性能的影响
Effect of toughening agent on mechanical properties of encapsulation adhesive
1.以聚氨酯、303、二丁酯为增韧剂,其对拉伸性能和冲击强度的影响见表2。从表2可以看出:由聚氨酯、303、二丁酯增韧改性后的环氧体系,与纯环氧树脂比较拉伸强度均有不同程度的下降。聚氨酯改性环氧树脂比改性前降低了16.2%,303改性降低了26.0%,而由二丁酯改性后的强度下降不大,只降低了2.4%。增韧改性后断裂伸长率均有所提高,由303改性环氧体系提高了29.7%;二丁酯改性环氧体系提高了37.9%;聚氨酯改性环氧树脂体系断裂伸长率则提高了80.8%。增韧剂改性后的冲击强度均较改性前有较大幅度的提高。由二丁酯、303和聚氨酯改性环氧树脂分别较纯环氧树脂提高了53.1%、61.2%和83.6%,提高幅度较大。综合比较三种增韧剂各种力学性和粘接性能数据可以看出:由聚氨酯增韧环氧休系效果较好。
1. the influence of polyurethane, 303 and two butyl ester as
toughening agents on tensile properties and impact strength is shown in
Table 2. It can be seen from table 2 that the epoxy system which is
toughened by polyurethane, 303, and two butyl ester has a different
degree of decrease in tensile strength compared with that of pure epoxy
resin. The epoxy resin modified by polyurethane decreased by 16.2%
compared with that before modification, while the 303 modification
decreased by 26%. The strength of the modified epoxy resin decreased
only by 2.4% after modification by two butyl ester. After toughening and
toughening, the elongation at break increased by 29.7%, the epoxy
system of two butyl ester was increased by 37.9%, and the elongation at
break of the modified epoxy resin system of the polyurethane modified by
303 was increased by 80.8%. The impact strength of the toughening agent
after modification is higher than that before modification. The epoxy
resin modified by two butyl ester, 303 and polyurethane increased 53.1%,
61.2% and 83.6% respectively than that of pure epoxy resin. By
comparing the mechanical properties and adhesive properties of the three
toughening agents, it can be seen that the effect of polyurethane
toughening epoxy system is better.