The principle of polyester profiles mainly involves the preparation process of polyester as a polymer material, which includes two key steps: esterification reaction and polymerization reaction. Polyester is a polymer compound composed of repeating structural units connected by ester bonds, which is divided into two categories: linear polyester and cross-linked polyester. Common polyesters include polybutylene glycol (PBT) and polyethylene terephthalate (PET).
Esterification involves the reaction between anhydrides (anhydrides formed by organic acids) or anhydrides and alcohols. In the preparation of polyester, commonly used anhydrides include terephthalic anhydride, while alcohols include ethylene glycol, propylene glycol, etc. These raw materials gradually generate ester bonds through hydrolysis and condensation reactions in the esterification reaction, so that the monomer molecules gradually polymerize to form polymer compounds.
Polymerization reaction is the reaction between anhydrides and diols. In this process, anhydrides and diols first form intermediate esters through esterification reaction, and then further undergo polycondensation reaction under heating, dehydration and other conditions. Through polymerization, monomer molecules can be connected into linear or cross-linked polymer chain structures. The preparation process of polyester materials mainly includes the above steps. Through these chemical reactions, the raw materials are converted into polyester profiles with specific physical and chemical properties1