Synthesis of high‐molecular weight poly(trimethylene terephthalate) catalyzed by MoO₃ supported Al₂O₃‐TiO₂ catalysts

Abstract

Poly(trimethylene terephthalate) (PTT) is an excellent fiber materials. Although it was synthesized as early as 1940s, obtaining high-molecular weight PTT suitable for spinning is not easy due to no evident breakthrough in the catalysts for PTT synthesis. Patents and literatures disclosed a lot of the catalysts of preparing PTT, but which are more or less disadvantageous. Based on acid catalytic mechanism of PTT preparation, a series of solid acid as x% MoO 3 /(50% Al 2 O 3 À 50% TiO 2 ) (briefly written as xM/(A À T), x ¼ 0, 10, 15, 20 by weight) were prepared by sol-gel coprecipitation and wetting impregnation methods, and first used for PTT synthesis in this work. When 50% Al 2 O 3 À 50% TiO 2 (briefly written as A À T) was supported by MoO 3 using wetting impregnation technique of (NH 4 ) 6 Mo 7 O 24 .4H 2 O aqueous solution, a lot of Brunsted acid and Lewis acid sites were formed on xM/(A À T) catalyst surfaces, which was confirmed by the characteristics of their NH 3 -TPD (temperature programmed desorption). All the prepared catalysts were highly active ones toward synthesis of PTT. PTT with high-intrinsic viscosity (IV) was obtained in the presence of trace amount of the catalysts. IV ranging of the PTT synthesized from 0.66 to 0.95 dL g À1 corresponds to weight average molecular weight ðM w Þ from 49,197 to 73,004.

Cost-Effective Sustainable Synthesis of High-Performance High-Molecular-Weight Poly(trimethylene terephthalate) by Eco-Friendly and Highly Active Ti/Mg Catalysts

“…As a result, the cost of producing PTT is considerably higher than that of PET. Efficient catalyst is a key factor in economic synthesis of PTT and other polymers and various attempts have been made to achieve high molecular weight with improved catalysts. − Titanium catalysts including titanium dioxide and titanate are most studied for PTT synthesis. − ,,− Titanium dioxide and its modifiers were first used in PTT synthesis. Their catalytic activity is highly depending on the particle size and molecular structure.…”

Chemicals from Coal Coking

“…PET is mainly used to produce fibres and plastic containers, such as bottles. Poly(trimethylene terephthalate) is an aromatic polyester obtained by the reaction of terephthalic acid with 1,3-propanediol 54,55,56 . The conventional route of synthesis requires the use of high temperature, high-vacuum systems and the presence of a catalyst to favour the reaction.…”

“…Poly(trimethylene terephthalate) is an aromatic polyester obtained by the reaction of terephthalic acid with 1,3-propanediol. − The conventional route of synthesis requires the use of high temperature, high-vacuum systems, and the presence of a catalyst to favor the reaction. Of the catalysts tested, those containing titanium seem to be the most appropriate (e.g., titanium dioxide).…”