Synthesis And Properties Research Of Hot Melt Adhesives For Metal Alumina/Polypropylene Plastic Bonding

In this paper, a kind of hot melt adhesive used for metal alumina and polypropylene plastic bonding was synthesized, and its properties were characterized.The dimer acid-based copolyamides resin (PA) were synthesized from dimer acid, piperazine, sebacic acid, ethylenediamine and blocked with 1-hexadecylamine. The effect of the content change of piperazine and 1-hexadecylamine on the properties of PA was investigated, the raw material ratio of PA having good adhesive performance for aluminum and polypropylene (PP) plastic was obtained.The blends were prepared from the above-mentioned PA and linear low density polyethylene (LLDPE), the effect of the content change of the compatibilizer, maleic anhydride grafted linear low density polyethylene (LLDPE-g-MAH), on the properties of blends such as mechanical properties, crystallization and melting behavior, thermal properties and microstructure were investigated. The results showed that the blend containing 9.0% LLDPE-g-MAH exhibits an optimal mechanical properties. As the content of LLDPE-g-MAH increases, the crystallinity of the polyamide in the blends decreased, while the crystallization temperature of LLDPE increased. Thermogravimetric analysis showed that the blends had high thermal stability. The scanning electron microscope analysis showed that LLDPE-g-MAH reduced the particle size of LLDPE phase in the blends, which promotes the fusion of different phases, the microscopic structure of system becomes uniform stability.The hot melt adhesives used for aluminum and PP bonding were synthesized by blending the ternary blends (PA/LLDPE/LLDPE-g-MAH) with other additives, the adhesive property for aluminum/PP of the hot melt adhesives were researched by changing the kind and content of the compatibilizer, and the content of tackifier and coupling agent, etc on. The results show that the peeling strength of pilot test sample of modified hot melt adhesives for aluminum/PP was 138.5N/2.5cm, and the rupture occured inside the bulk, called cohesive fracture, which demonstrating that the modified hot melt adhesives had a strong adhesion strength for aluminum/PP.