Hydrolytic degradation of poly(1,4-butylene terephthalate-co-tetramethylene oxalate) copolymer

Abstract

Experimentally synthesized poly(1,4-butylene terephthalate-co-tetramethylene oxalate) (PBT-PTMO) monofilaments were evaluated for hydrolytic stability in salt water (SW) and distilled water (DW) at temperature below and above glass transition temperature (T g ), along with commercially available poly(hexamethylene adipamide) (NY), poly(ethylene terephthalate) (PET), and polypropylene (PP) monofilaments. There was no decrease in mechanical properties in case of NY, PET, and PP in either DW or SW below their T g . The breaking strength, ultimate elongation, and thermal shrinkage of the PBT-PTMO, however, decreased as the ageing time increased. Total strength loss occurred after approximately 300 days at 25°C in either DW and SW. This can be attributed to the chain scission that occurs in the PBT-PTMO copolymer chain. The poor hydrolytic stability of the PBT-PTMO may be attributed to the higher moisture regain. The salinity of water did not have a significant effect on the breaking strength loss of the materials. The mode of hydrolytic degradation of aged PBT-PTMO polymer was confirmed by the increasing generation of the acid carbonyl and hydroxyl groups with concomitant increasing consumption of ester groups, regardless of ageing conditions. Above T g , the hydrolytic rate constant (kЈ H , day Ϫ1 ) of the PBT-PTMO, estimated by the rate of formation of acid carbonyl groups, is greater at a higher ageing temperature.

Polyoxalates from biorenewable diols via Oxalate Metathesis Polymerization

“…4 Later in 1998 Shin et al synthesized poly(1,4-butylene terephthalate-co-tetramethylene oxalate) (PBT-PTMO) monolaments and evaluated the hydrolytic stability in salt water and distilled water at temperatures below and above the T g , along with comparative studies for commercially available poly(hexamethylene adipamide), poly(ethylene terephthalate), and polypropylene; the breaking strength, ultimate elongation, and thermal shrinkage of the PBT-PTMO decreased while the other polymers showed no variations. 10 In 2002 Lotti and coworkers copolymerized azelaic acid with diethyl oxalate and butanediol in different proportions and reported lower T g and T m with increasing azelaic acid incorporation. 11 In 2006 Sheng et al synthesized poly(ethylene oxalate-co-terephthalate-co-sebacate), and acquired thermal and mechanical data for these copolyesters.…”

Fully Bio‐Based 2,5‐Furandicarboxylic Acid Polyester toward Plastics with Mechanically Robust, Excellent Gas Barrier and Fast Degradation

“…The CA decreased from 77.2° to 62.9° with increasing BO content. That was attributed to the interaction of neighboring carbonyl groups in the BO units, which led to stronger binding of carbonyl and water, resulting in increased hydrophilicity [22] …”

“…That was attributed to the interaction of neighboring carbonyl groups in the BO units, which led to stronger binding of carbonyl and water, resulting in increased hydrophilicity. [22] For food packaging and green agricultural films, the permeability coefficient was an important parameter for measuring the barrier property of the films. The permeability coefficients of CO 2 and O 2 were studied by the pressure measurement method, and the permeability to H 2 O was studied by the weight loss method as shown in Figure S5 (b), and the barrier improvement factors (BIFp) of PBOF with different BO content were measured using the permeability coefficient of commercial PBAT as a reference (Table S4).…”