Preparation And Characterization Of Modified Thermoplastic Polyurethane Adhesive

In this study, the preparation, characterization and adhesive application of modified thermoplastic polyurethane (TPU) were researched. In order to improve the properties of TPU adhesive, physical blending, atom transfer radical polymerization (ATRP), chemical grafting and block modification method was used to modify TPU, analyzing the data of tensile properties, peel strength and thermo properties.Firstly, physical blending was used to modify TPU and effectively remend the shortcoming of TPU which is resulted from its incompatible soft and hard segments by using polypropylene (PP). The ratio of blends has been determined by measurement of different proportions of TPU, PP, and compatibilizer. The best ratio of TPU/PP/PP-g-MAH is 70/30/4.In the subject, methyl methacrylate (MMA) was grafted to the ends of TPU via ATRP, which was a innovative way to apply it to the adhesive. TPU was processed through cleaning, activation and preparation of macroinitiator on the basis of commercial particles. Eventually, MMA was grafted via ATRP grafting reaction. The results show that, MMA was grafted to both ends of TPU effectively. Meanwhile, the method improved characterization of TPU effectively.In order to improve the initial adhesion, rosin was choosed as grafting monomers to modify TPU. Experiments show that the untreated modified TPU film peel strength can be increased 19.02%, while the modified TPU film heat-treated peel strength can be increased 43.65%.In the research, diamine agent was used to modify TPU, because it can form a block-by-block structure to improve the micro-phase separation of TPU and mechanical properties. Different ratio of TPU and MCDEA were measured by 1H-NMR and GPC. The results show that tensile properties were the best when the mol ratio was 1/7. However, considering the toxicity of MOCA and DMTDA, it is appropriate to choose MCDEA.In order to improve thermo properties of TPU, exoxy resin and silane coupling agent were used to modify TPU. The results show that the thermo properties of TPU have been improved by oxazolidinone and KH550. Meanwhile, from the data of tensile properties, it is better to put epoxy resin and KH550 at the same time.