High clarity polyurethane laminating adhesives based on poly (propylene glycol). Effect of hard segment on microphase morphology, haze and adhesion

Within this publication, the performance of high clarity polyurethane adhesives based on a poly(propylene glycol) soft-phase within polycarbonate or ethanolamine surface-treated laminate, is described. A series polyurethanes were prepared, with used as due to polyol and absence carbonyl functionality, which allows for hard-phase architecture be resolved greater resolution. In total, eight synthesised, each contained different chain-extender formulation gauge what influence had laminate haze peel strength. This was investigated using either 4,4-methylene diphenyl diisocyanate isophorone trimethylolpropane only by including one following sterically hindered diols: 2,2-diethyl-1,3-propane diol, 1,3-butane diol 1,2-proane diol. DSC analysis showed that microphase morphology strongly influenced present, shown degree phase mixing being in methylene formulations when compared based. ATR complements observed difference morphology, having composition hydrogen-bonded urethane urea functionality present displays more separated composition. Interestingly, differences did not have consistent strength obtained, 31% combinations tested recording <3 N mm−1 after 18 months. Diol chain-extended accounted 25% these lower values consequence their poorer process-ability during lamination. resulted higher encountered both laminates formulations, where all <1.5%.