Hot Melt Adhesives

Polyamide thermoplastic elastomer (TPEA) is composed of high melting point crystalline polyamide hardness and amorphous polyester or polyether soft satin. According to the raw materials required for the synthesis of polyamide thermoplastic elastomer, the synthesis methods can be divided into dibasic acid method and isocyanate method. Tpae was prepared by esterification of carboxyl terminated aliphatic polyamide block and hydroxyl terminated polyether diol. Isocyanate process uses semi aromatic amide as hard segment and aliphatic polyester, polyether or polycarbonate as soft segment. Using isocyanate method, the hard segment of semiaromatic amide is obtained by the reaction of aromatic diisocyanate and dicarboxylic acid, rather than by the traditional polymerization of diamine and dicarboxylic acid, ring opening polymerization of cyclolactam or the reaction of diamine and dicarboxylic chloride. In contrast, the former avoids the problems of low activity of aromatic binary amines, difficult to obtain and react with aromatic cyclolactam monomers to release corrosive hydrogen chloride.