What are the commonly used toughening agents?

Commonly used toughening agents include: (1) unsaturated polyester resin. For example, 302 polyester, 304 polyester, 305 polyester, etc. (2) Rubber, such as polysulfide rubber, nitrile rubber, hydroxyl terminated liquid nitrile rubber, thiol terminated nitrile rubber, chloroprene rubber, polychloroester rubber, etc. (3) Polyamide resin. One is a low molecular polymer consisting of dimerized or tripled vegetable oil, unsaturated fat acid or aromatic acid and alkyl polyamine; One type is modified nylon such as hydroxymethyl nylon (SY-7, SY-8, and (used for GXA-1 adhesive). (4) Acetal resin. Such as polyvinyl formal, polyvinyl acetal, polyvinyl methylhexanal, polyvinyl butyral, polyvinyl furfural, etc. (5) Polysulfone orange fat. (6) Polyurethane resin.