Polyester tackifying/nucleating special auxiliary agent, preparation thereof and application thereof in PET modification

The invention discloses a polyester tackifying/nucleating special auxiliary agent, preparation thereof and application thereof in PET modification. The polyester tackifying/nucleating special auxiliary agent is inorganic nonmetal particles with functional groups and short-chain alkyl groups on the surfaces, wherein the inorganic nonmetal particles are obtained by conducting surface modification oninorganic nonmetal particles through a silane coupling agent; the silane coupling agent is composed of at least one silane coupling agent with the function groups at the terminals and at least one silane coupling agent with the short-chain alkyl groups at the terminals, the functional groups are groups capable of reacting with -OH or -COOH at polyester molecular chain terminals, and the carbon number of the short-chain alkyl groups is 3-8; the surfaces of the inorganic nonmetal particles contain hydroxyl groups or carboxyl groups, and the particle size of the inorganic nonmetal particles is within the range of 10-200 nm. By means of the auxiliary agent, polyester tackifying and induced crystallization nucleation can be achieved simultaneously. The invention further provides a PET modification method which is simple, low in cost and capable of achieving PET tackifying and induced crystallization nucleation simultaneously.