Chain extension of adipic acid and (or) succinic acid/butanediol polyesters with 2,2′‐(1,4‐phenylene)‐bis(2‐oxazoline) and adipoylbiscaprolactamate combined chain extenders

Abstract

This paper provided an easy and flexible method to synthesize high molecular weight polyesters by polycondensation and chain extension. Low molecular weight polybutylene adipate, polybutylene succinate, and poly(butylene succinate‐co‐butylene adipate) (PBSA) were synthesized through melt condensation polymerization from adipic acid and/or succinic acid with butanediol. The prepolyesters obtained had different amount of COOH and OH terminal groups. Chain extension of them was carried out at 180–240°C using 2,2′‐(1,4‐phenylene)‐bis(2‐oxazoline) and adipoyl biscaprolactamate as combined chain extenders. The influencing factors of the chain extension were studied. At the optimal conditions, chain‐extended polybutylene adipate with Mn up to 39,100, polybutylene succinate with intrinsic viscosity of 0.99 dl/g, and PBSA with intrinsic viscosity from 0.73 to 0.81 dl/g were synthesized. The chain‐extended polyesters were characterized by IR spectrum, 1H NMR spectrum, differential scanning calorimetry, thermogravimetric analysis (TGA), wide angle X‐ray scattering, and tensile test. The thermal analysis showed that chain extension often led to slight decrease of the regularity, the crystallinity, and the melting point. This deterioration of the properties is not harmful enough to impair their thermal properties and obstruct them from being used as biodegradable thermoplastics. The TGA showed that the chain‐extended polyesters were stable with initial decomposition temperature over 354.7°C. The tensile strength of the chain extended PBS and PBSAs with butylene adipate units less than 20 mol% was in the range of 18.95–31.22 MPa. Copyright © 2010 John Wiley & Sons, Ltd.

Synthesis and characterization of aliphatic polyesteramides mainly composed of alternating diester diamide units from N,N′‐bis(2‐Hydroxyethyl)‐oxamide and diacids

“…PBOX and ABC were effective chain extenders in the chain extension of the HOOC‐ or HO‐ terminated polymers such as polyesters and polyamides to increase the molecular weight in short time . PBOX and ABC were also used as combined chain extenders in the chain extension of the aliphatic polyesters and random polyesteramides having both HOOC‐ and HO‐ terminal groups . PrePEA(0,4)s were terminated by both HO‐ and HOOC‐ groups, so PBOX and ABC were chosen as combined chain extenders.…”

Synthesis and Properties of Polyesteramides Having Short Nylon-610 Segments in the Main Chains through Polycondensation and Chain Extension

“…For some kinds of chain extenders, chain extension can be completed in several minutes. − Chain extenders such as bisoxazolines − and terephthaloyl biscaprolactamate − are often used to enhance the molecular weight of poly(ethylene terephthalate) (PET), aliphatic polyamides, and aliphatic polyesters with the HOOC– or HO– terminal groups, respectively. For the chain extension of the polymers having both the HOOC– and the HO– terminal groups, combined chain extenders were used …”

“…For the chain extension of the polymers having both the HOOC− and the HO− terminal groups, combined chain extenders were used. 30 In this paper, a series of polyesteramides having short nylon-610 segments in the main chains were synthesized. Nylon-610 has high T m ; introducing nylon-610 segments in the main chains might increase the intermolecular interaction between the polyamide segments and lead to the increase of the mechanical strength of the polyesteramides obtained.…”

Preparation Methods, Performance Improvement Strategies, and Typical Applications of Polyamide Foams

“…Adding optimized chain extenders to improve the melt strength of PA materials during the foaming process is an effective strategy to modify PA. Among them, epoxy resin, oxazoline, , and oxazine are widely used chain extenders, based on their interactions with carboxyl and amino groups as the end groups of the PA structure. Among the chain extenders, epoxy groups are the most widely used.…”