2017 Volume 53 Issue 7 Pages 235-243
In this study, maleimide copolymers with reactive side groups were synthesized and their thermal curingbehavior and adhesion properties for metal bonding were investigated. First, three kinds of copolymers wereprepared by radical copolymerization of N-allylmaleimide（ AMI） with 2-ethylhexyl acrylate（ 2EHA） andn-butyl vinyl ether（ BVE） and their composition was determined by 1H NMR spectroscopy. As a result, weobtained random copolymers with 2EHA containing 25 and 37 mol% of AMI repeating units and alternatingcopolymer with BVE containing 55 mol% of AMI. These copolymers containing a reactive allyl group wererevealed to have onset temperatures of decomposition over 330℃ . By thermal curing using ene-thiol reactionbetween the allyl group and pentaerythritol tetrakis（ 3-mercaptobutyrate）（ PEMB）, crosslinking structurewas formed during heating at 140-160℃ leading to formation of insoluble cured products. The conversion ofallyl groups was determined to be approximately 60% by IR spectroscopy, being enlarged by the addition oftriallyl isocyanurate（ TAIC）. A tensile lap shear test was carried out using stainless steel（ SUS） plates adheredwith the blends of the copolymer with PEMB and TAIC as adhesives to evaluate adhesive properties for metalbonding. After thermal curing in the presence of PEMB, the adhesive strength was in a range of 4.3-5.2 MPaand it increased to 6.4 MPa by the addition of TAIC.
