Preparation method of phosphonitrile chloride catalyst, and application of phosphonitrile chloride catalyst in preparation of alkoxy-terminated polysiloxane

Abstract

The invention discloses a preparation method of a phosphonitrile chloride catalyst, and an application of the phosphonitrile chloride catalyst in the preparation of alkoxy-terminated polysiloxane. Thepreparation method comprises the following steps: purging a reaction device with nitrogen to achieve preheating treatment, opening the reaction device to remove condensate water, and sequentially infiltrating the reaction device with dichloromethane and tetrachloroethane; mixing and uniformly stirring tetrachloroethane and ammonium chloride to prepare a tetrachloroethane solution of ammonium chloride for later use; adding phosphorus pentachloride into the reaction device, slowly raising the temperature to 140-160 DEG C under the protection of nitrogen, then dropwise adding the prepared tetrachloroethane solution of ammonium chloride, carrying out a reflux reaction after the drop-by-drop addition is completed, then raising the temperature to 170-175 DEG C, continuously carrying out the reflux reaction, and cooling the reaction device to room temperature after the reaction is completed; and adding anisole into the reaction solution, and performing stirring under a vacuum condition to achieve uniform mixing in order to obtain target crystals which are the phosphonitrile chloride. The prepared phosphonitrile chloride has a high catalytic activity; and when the phosphonitrile chlorideis used for preparing alkoxy-terminated polysiloxane, a polymer with an excellent storage stability can be effectively prepared.

Description

Technical field: [0001] The invention relates to the field of catalyst preparation, in particular to a preparation method of a phosphazene chloride catalyst and its application in the preparation of alkoxy-terminated polysiloxane. Background technique: [0002] In recent years, with the development of the economy, the construction industry is constantly innovating and reforming to meet people's growing pursuit of quality in the living environment. Polysiloxane sealant is an effective sealant for many years. It is mainly a one-component or two-component sealant formulated with silicone rubber as the main material. Its sealing performance, weather resistance and temperature resistance And good operability, it has good bonding and sealing performance for vulcanized rubber, metal, various plastics, glass, fabric, paint, etc. It is widely used in interior and exterior walls of buildings and kitchen and bathroom furniture. [0003] At present, most of the sealants on the market a...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the sealants on the market are silicone systems, but the traditional silicone sealants have a molecular structure of hydroxyl-terminated polydimethylsiloxane and a methoxyl coupling agent, which are produced under the combined action of catalysts and moisture. The silanol condensation reaction leads to crosslinking. Since the polymer 107 is hydroxyl-terminated, it will react with the crosslinking of silane and methanol to form a monomethoxyl group during storage, so the phenomenon that the storage period is too long and the viscosity will not be cured. peak

In order to solve this problem, people try to modify 107 with polyalkoxysilane under the condition of catalyst catalysis to prepare alkoxy-terminated polydimethylsiloxane; for example, amine compounds can catalyze orthosilicon Acetate methyl ester and vinyltrimethoxysilane can block 107, but the reaction conditions are relatively high, and the organic amine is difficult to remove, which will bring a strong odor to the product

Moreover, with the deepening of research on the preparation of end-capped polysiloxane bodies, various catalysts have also appeared. Potassium acetate can catalyze the end-capping reaction at room temperature, but the end-capping efficiency is low; alkali metal hydrogen Oxide has a good catalytic effect on polyalkoxysilane capping 107, and can catalyze various polyalkoxysilanes to complete the capping reaction under normal temperature and normal pressure conditions, but its reaction time is long and difficult to remove. Product transparency is also poor