Introduction to chemical modification
Chemical modification is a method of changing the physical and chemical properties of polymers through chemical reactions. For example, the rigid segment of polystyrene is too rigid, and the soft segment of polyethylene can be introduced to increase the toughness. The end groups (amino, carboxyl, hydroxyl, etc.) of polymers such as nylon and polyester can use monobasic acids (benzoic acid or ethyl acetate). Acid anhydride), monohydric alcohols (cyclohexanol, butanol or benzyl alcohol, etc.) for end group blocking; alkyd polyesters formed by polycondensation of polyhydric alcohols and polybasic acids have poor water resistance and toughness, and can be significantly modified by adding fatty acids Improve its moisture resistance and water resistance, and the elasticity is correspondingly improved.