Catalyzed chain extension of poly(butylene adipate) and poly(butylene succinate) with 2,2′‐(1,4‐phenylene)‐bis(2‐oxazoline)

Abstract

Low-molecular-weight HOOC-terminated poly(butylene adipate) prepolymer (PrePBA) and poly(butylene succinate) prepolymer (PrePBS) were synthesized through melt-condensation polymerization from adipic acid or succinic acid with butanediol. The catalyzed chain extension of these prepolymers was carried out at 180-220 C with 2,2 0 -(1,4-phenylene)-bis(2-oxazoline) as a chain extender and p-toluenesulfonic acid (p-TSA) as a catalyst. Higher molecular weight polyesters were obtained from the catalyzed chain extension than from the noncatalyzed one. However, an improperly high amount of p-TSA and a high temperature caused branching or a crosslinking reaction. Under optimal conditions, chain-extended poly (butylene adipate) (PBA) with a number-average molecular weight up to 29,600 and poly(butylene succinate) (PBS) with an intrinsic viscosity of 0.82 dL/g were synthesized. The chain-extended polyesters were characterized by IR spectroscopy, 1 H-NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, wide-angle X-ray scattering, and tensile testing. DSC, wide-angle X-ray scattering, and thermogravimetric analysis characterization showed that the chain-extended PBA and PBS had lower melting temperatures and crystallinities and slower crystallization rates and were less thermally stable than PrePBA and PrePBS. This deterioration of their properties was not harmful enough to impair their thermal processing properties and should not prevent them from being used as biodegradable thermoplastics. The tensile strength of the chain-extended PBS was about 31.05 MPa. V C 2009 Wiley Periodicals, Inc. J Appl Polym

Highly thermostable and crystalline poly(butylene adipate) bionanocomposites prepared by in situ polycondensation with organically modified Moroccan beidellite clay

“…The percentage crystallinity was calculated as: X c = 100Δ H m /Δ H m ° (ΔH m ° = 135 J g −1 for 100% crystalline PBA).…”

Synthesis and characterization of the novel nylon 12 6 based on 1,12‐diaminododecane

“…The acid value or amine value was detected using the similar method described in the literature . The number‐average molecular weight of nylon 12 6 was recorded on Agilent 2600 series equipped with a PLgel 5 μm × 100 nm column and a refractive index detector at 25 ° C. N,N‐Dimethylformamide (DMF) was used as the eluent at a flow rate of 1 mL/min and polystyrene was used as the standard.…”

Preparation and characterization of chain extended Poly(butylene succinate) foams

“…In order to modify the inferior properties of biodegradable polymer, numerous methods were employed, such as chain extension, nanocomposite, crosslinking, and so on . Chain extension is a commonly swift and efficient method.…”

“…Mihai et al employed a multifunctional styrene‐acrylicepoxy copolymer as chain extender to improve the molecular structure and rheology property of PLA, and found that chain extended PLA exhibited obvious strain‐hardening phenomenon, resulting in well foam ability . The catalyzed chain extension of PBS was carried out with 2,2′‐(1,4‐phenylene)‐bis(2‐oxazoline) as a chain extender and p‐toluenesulfonic acid as a catalyst by Huang et al, giving rise to a higher molecular weight and intrinsic viscosity . PBS was chain‐extented with poly (butylene carbonate) using hexamethylene diisocyanate as chain extender, bringing about satisfactory thermal and mechanical properties .…”