A method for accelerating the transformation of crystal form II to crystal form I by applying flow shear to isotactic polybutene-1 structure melt

Abstract

The invention discloses a method for applying flow shearing to isotactic polybutylene-1 structure melt to accelerating conversion from a crystal form II to a crystal form I. By means of the method, afusion index instrument is used for preparing the isotactic polybutylene-1 structure melt at a certain temperature, then extrusion is carried out under the flow shearing effect, and the isotactic polybutylene-1 can be converted from the crystal form II to the crystal form I within a very short time. By means of the method, no auxiliaries, fillers and the like need to be added in the preparing process, conversion from crystal form II to the crystal form I of the isotactic polybutylene-1 can be accelerated, influences on transparency, purity and the like of the isotactic polybutylene-1 can be avoided while conversion from the crystal form II to the crystal form I of the isotactic polybutylene-1is accelerated, wide application of the isotactic polybutylene-1 with the excellent performance toall fields is obviously promoted, meanwhile, the production cost is reduced, and the very good socioeconomic performance is achieved.

Description

technical field [0001] The invention belongs to the technical field of polymer processing. The invention relates to a method for accelerating the transformation of crystal form II to crystal form I by applying flow shear to isotactic polybutene-1 structure melt. Specifically, it is a method for accelerating the transformation of crystal form II of isotactic polybutene-1 to crystal form I through structural melt and flow shear. [0002] technical background [0003] Isotactic polybutene-1, referred to as iPB-1, is a high-isotactic polymer, thermoplastic polymer material, with outstanding thermal creep resistance, environmental stress cracking resistance, good toughness, durability, chemical Stability and plasticity, known as "gold in plastics" for its excellent physical and chemical properties, is one of the most cutting-edge chemical materials in the world. The excellent performance of polybutene-1 makes it still have excellent mechanical properties under heated conditions,...

AI Technical Summary

Problems solved by technology

Under normal processing conditions, the prepared isotactic polybutene-1 product is crystallized by cooling directly from high temperature to room temperature and normal pressure to obtain crystal form II, but crystal form II is a metastable crystal form. It will spontaneously transform to the more stable crystal form I. The crystal form I obtained after the transformation has excellent stability and a wide range of uses, but the transformation process takes about 7-14 days

The crystal transformation characteristics of isotactic polybutene-1 greatly increase the time cost, which greatly limits the application of polybutene-1 products in various fields

[0005] At present, in order to make better application of polybutene-1 with excellent performance, there have been technical researches on its crystal transformation, but most of them use CO 2 High pressure, adding fillers, additives, etc. to achieve a faster transformation of the crystal form, although these technologies can promote the transformation of polybutene-1 crystal form to a certain extent, but high pressure requires harsh conditions and the addition of various additives etc. will have a certain impact on its properties such as transparency and purity, but its application is still limited and cannot be better applied.

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