噁唑烷酮改性环氧树脂的性能

Mechanical and thermal properties of oxazolidone modified epoxy resin

采用4,4-二苯基甲烷二异氰酸酯(MDI)对双酚A环氧树脂和脂肪族环氧树脂进行噁唑烷酮化共改性,研究了MDI及作为活性稀释剂的脂肪族环氧用量对改性产物黏度及树脂固化物力学性能、耐热性的影响。结果表明,低改性比和稀释剂可以有效降低唑烷酮改性环氧树脂黏度,当改性比为4∶1时,树脂固化物拉伸强度、弯曲强度达到75.4 MPa和158.2 MPa,分别比环氧树脂固化物提高了64%和57%,断裂延伸率和冲击强度有较大提高,具有高强高韧的特点。稀释剂含量对Tg影响较小,各改性树脂Tg在108～118℃之间,与纯环氧树脂的耐热性相当。

Oxazolidone ring was introduced into epoxy resin by reacting 4,4’-diphenylmethane diisocyanate （MDI） with epoxy resin composed of bisphenol A epoxy resin and aliphatic epoxy resin. The viscosity of modified epoxy resin,mechanical and thermal properties of cured resin were studied by changing the content of aliphatic epoxy resin which was used as reactive diluent and MDI. The viscosity of oxazolidone modified epoxy resin could be reduced effectively when modification ratio was decreased and content of diluent was increased. When modification ratio was 4∶1,tensile strength and bending strength of cured resin reached 75.4 MPa and 158.2 MPa. The values were increased by 64%and 57%respectively compared with those of bisphenol A epoxy resin cured samples. Elongation and impact strength were also greatly improved. Oxazolidone modified epoxy resin exhibited high strength and toughness. Diluent content indicated a small influence on glass transition temperature （Tg）. The Tg of oxazolidone modified epoxy resin was between 108 ℃ and 118 ℃. Oxazolidone modified epoxy resin possessed thermal resistance as bisphenol A epoxy resin.