The present study aimed to develop adhesives for bonding natural rubber (NR) to steel based on modified NR bearing grafted poly(acetoacetoxyethyl methacrylate), NR-g-PAAEM. Graft copolymers of NR-g-PAAEMs were prepared by emulsion polymerization at 50 °C. A significant increase in the polar component of NR from 1.62 to 6.84 mN/m was observed after grafting modification, indicating an increase in its hydrophilicity. After that, both one-coat and two-coat adhesives (or adhesive/cover-coat system) were then prepared, using polyisocyanate (poly‐HDI) as a bonding agent. The NR/steel joints were made by vulcanization bonding, using the NR-g-PAAEM adhesive in the presence or absence of cover-coat layer. The results reveal that the NR/steel joint bonded using the two-coat system exhibited higher peel strength than that bonded using the one-coat system. For the two-coat system, the peel strength of 874 N/m was attained when the NR-g-PAAEM adhesive was used in combination with the NR cover-coat. The replacement of the NR cover-coat by the NR-g-PAAEM20 cover-coat led to 49% increase in peel strength of the NR/steel joint. Moreover, the X-ray photoelectron spectroscopy analysis also indicated the formation of urethane-like bonding in this adhesive system, as a result of the reaction between the poly‐HDI and metal oxides on the steel surface.

中文翻译：

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基于天然橡胶与聚甲基丙烯酸乙酰乙酰氧乙酯接枝的橡胶-钢制胶粘剂

本研究的目的是开发基于天然橡胶（NR）接枝的聚（甲基丙烯酸乙酰乙酰氧乙酯）NR-g-PAAEM的天然橡胶（NR）与钢的粘合粘合剂。NR-g-PAAEMs的接枝共聚物是通过在50°C下乳液聚合制备的。接枝改性后，NR的极性成分从1.62到6.84 mN / m显着增加，表明其亲水性增加。之后，然后使用多异氰酸酯（poly-HDI）作为粘合剂制备单层和两层粘合剂（或粘合剂/面漆体系）。在存在或不存在覆盖涂层的情况下，使用NR-g-PAAEM粘合剂通过硫化粘合来制造NR /钢接头。结果表明，使用双涂层系统粘合的NR /钢接头比使用单涂层系统粘合的NR /钢接头具有更高的剥离强度。对于两涂层体系，当将NR-g-PAAEM粘合剂与NR覆盖涂层结合使用时，剥离强度达到874 N / m。用NR-g-PAAEM20覆盖层代替NR覆盖层导致NR /钢接头的剥离强度提高了49％。此外，X射线光电子能谱分析还表明，由于聚-HDI与钢表面金属氧化物之间的反应，在该粘合剂体系中形成了类似氨基甲酸酯的键合。