Controlled Branching by Step-Growth Polymerization of Xylitol and Succinic Acid via Microwave Irradiation

Abstract

Copolymerization of xylitol usually yields cross-linked materials. In this work, microwave-assisted polyesterification of xylitol and succinic acid produced materials with diverse molecular weights and different branching degrees, and more importantly, no cross-linking was observed, as supported by the solubility behavior and spectroscopic data. Reactions were carried out for short times, less than 20 min, which is not common for production of industrial polyesters. Control over the branching degree was achieved by tuning the reaction conditions, such as temperature, time of exposure, and monomer ratio, during microwave irradiation. No solvent or catalyst was employed during the step-growth polymerization.

Recycling/Upcycling of Physically Aged Poly(butylene succinate) into PBS Vitrimers through Zn(II)-Catalyzed Melt Vitrimerization

“…In the region of 1650 to 1750 cm –1 , PBS has a complex band, which is the convolution of four characteristic absorption bands of −CO stretching modes (Figure b). The first one, located at 1683 cm –1 , is a characteristic peak related to the −CO of the carboxyl end-group present in PBS, in the succinic moiety; its intensity and position correlates to the polymer degradation degree, especially in the case of our aged sample. Moreover, as first highlighted by Yao et al, the remaining three absorption bands of −CO stretching modes at 1712 cm –1 (sharp and intense band), 1720 and 1736 cm –1 (typically occurring as shoulder peaks) can be assigned to the crystalline ( x c ), rigid amorphous ( a rigid ) and mobile amorphous ( a mobile ) regions respectively, usually evident in a semi-crystalline polyester like PBS.…”

A Micro-Configured Multiparticulate Reconstitutable Suspension Powder of Fixed Dose Rifampicin and Pyrazinamide: Optimal Fabrication and In Vitro Quality Evaluation

“…Subsequently, C-O strong bends at 1100 cm −1 , O-H stretches at 2872 cm −1 and C-H stretches at 1354 cm −1 were observed from Kolliphor ® [ 86 ] in Figure 4 D. Specific peaks were noted at 1658 cm −1 for C=O groups, weak C-H stretches at 2974 cm −1 , C-N bends at 1282 cm −1 and 1418 cm −1 and O-H stretches at 3452 cm −1 for polyvinylpyrrolidone shown in Figure 4 E [ 87 ]. Furthermore, specific peaks of very large stretching O-H groups were noted at vibrations of 3244–3364 cm −1 , C-H stretches at 2924 cm −1 and C-C bends at 1432 cm −1 xylitol Figure 4 F [ 88 ]. These peaks indicate asymmetric stretching bands of CH 3 and CH 2 , respectively at vibrations of 2988 cm −1 and 2930 cm −1 .…”

Harnessing the power of polyol-based polyesters for biomedical innovations: synthesis, properties, and biodegradation

“…90 Xylitolbased polyesters can be synthesized through various methods, including melt polycondensation, microwave-assisted synthesis, and in situ crosslinking reactions. 91,92 Melt polycondensation is a commonly used method that involves reacting xylitol with diacids, such as succinic, adipic, suberic, and sebacic acid, under high temperatures and a controlled atmosphere. 93 By altering the diacid chain length, stoichiometric ratio, curing conditions, and the type of diacids used, researchers have been able to fine-tune the physicochemical properties, degradation rate, and mechanical properties of xylitol-containing polyol polyesters.…”