24968-12-5Relevant articles and documents
Preparation method of cyclic poly (butylene terephthalate) (by machine translation)
-
Paragraph 0040-0049, (2020/06/02)
The invention discloses a cyclic trimetric polybutylene terephthalate preparation method. The method comprises the steps: (a) preparing bis(4-(4-allyl terephthaloyl oxy)butyl)polyethylene terephthalate (III) from bis-(4-hydroxyl butyl)-polyethylene terephthalate (I) and 4-(allyloxy carbonyl)benzoic acid (II) under action of a condensing agent and an auxiliary reagent; (b) preparing cyclic trimetric polybutylene terephthalate precursor (IV) by ring closure of the bis(4-(4-allyl terephthaloyl oxy)butyl)polyethylene terephthalate (III) under the action of a Grubbs catalyst and lewis acid; (c) hydrogenating the cyclic trimetric polybutylene terephthalate precursor under the action of Pd/C to obtain cyclic trimetric polybutylene terephthalate (V). The preparation method disclosed by the invention has the advantages that the raw materials are cheap and easy to obtain, a synthesizing route is simple and short, a yield is high, and conditions are easy to control.(The formula is shown in the description.).
A practical synthesis of the cyclic butylene terephthalate trimer
Li, Xiaolin,Zhou, Pu,Wu, Wenxuan,Zhan, Li,Liu, Ting,Yang, Fan,Tang, Jie,Yu, Shanbao,Li, Hui,Luo, Yu
, p. 483 - 490 (2018/03/27)
This paper described a practical synthetic approach for the cyclic butylene terephthalate trimer (7). The key step was a ring-closing metathesis, using Grubbs' second-generation catalyst to form the macrocyclic ring. The advantages of this procedure included short reaction steps, simple operations and good yields.
Cyclic polybutylene terephthalate preparation
-
, (2017/07/01)
The invention specifically discloses a preparation method of novel cyclicpolybutylece terephthalate (PBT) dimer, wherein paraphthaloyl chloride and 1,4-butanediol are used as the raw materials for oriented synthesis of the cyclicpolybutylece terephthalate dimer through a protection and deprotectionstrategy, and the method is used for contrast analysis and detection of cyclicpolybutylece terephthalate dimer impurities in a PBT plastic. The chemical structural formula of the cyclicpolybutylece terephthalate dimer is described in the specification.