Thermal Degradation Processes of Aromatic Poly(Ether Sulfone) Random Copolymers Bearing Pendant Carboxyl Groups

Sulfonated Polyether Ketone Membranes Embedded with Nalidixic Acid-An Emerging Controlled Drug Releaser

The effective administration of medication has advanced over decades, but the medical community still faces significant demand. Burst release and inadequate assimilation are major drawbacks that affect wound healing efficiency, leading to therapy failure. The widespread application of polymers in biomedical research is significant. The polyether ether ketone (PEEK) family is known for its biocompatibility, inertness, and semi-crystalline thermoplastic properties. In our present studies, we have chosen a member of this family, polyether ketone (PEK), to explore its role as a drug carrier. The PEK backbone was subjected to sulfonation to increase its hydrophilicity. The response surface methodology (RSM) was used to optimize the sulfonation process based on the time, degree of sulfonation, and temperature. The PEK polymer was sulfonated using sulfuric acid at 150 °C for 6 h; back titration was performed to quantify the degree of sulfonation, with 69% representing the maximum sulfonation. SPEK and nalidixic sodium salt were dissolved in dichloroacetic acid to create a thin membrane. The physiological and morphological properties were assessed for the SPEK membrane. The studies on drug release in distilled water and a simulated body fluid over the course of 24 h revealed a controlled, gradual increase in the release rate, correlating with a mathematical model and demonstrating the zero-order nature of the drug release. Hemolysis on the SPEK membrane revealed lower toxicity. The SPEK membrane's biocompatibility was established using in vitro cytotoxicity tests on the Vero (IC50: 137.85 g/mL) cell lines. These results confirm that the SPEK membranes are suitable for sustained drug release.

Methods of Analyses for Biodegradable Polymers: A Review

Biodegradable polymers are materials that can decompose through the action of various environmental microorganisms, such as bacteria and fungi, to form water and carbon dioxide. The biodegradability characteristics have led to a growing demand for the accurate and precise determination of the degraded polymer composition. With the advancements in analytical product development, various analytical methods are available and touted as practical and preferable methods of bioanalytical techniques, which enable the understanding of the complex composition of biopolymers such as polyhydroxyalkanoates and poly(lactic acid). The former part of this review discusses the definition and examples of biopolymers, followed by the theory and instrumentation of analytical methods applicable to the analysis of biopolymers, such as physical methods (SEM, TEM, weighing analytical balance, etc.), chromatographic methods (GC, THM-GC, SEC/GPC), spectroscopic methods (NMR, FTIR, XRD, XRF), respirometric methods, thermal methods (DSC, DTA, TGA), and meta-analysis. Special focus is given to the chromatographic methods, because this is the routine method of polymer analysis. The aim of this review is to focus on the recent developments in the field of biopolymer analysis and instrument application to analyse the various types of biopolymers.

Synthesis and Characterization of Copoly(Ether Sulfone)s with Different Percentages of Diphenolic Acid Units

New functionalized Poly(ether sulfone)s having different molar ratio (10, 20, 30, 50, 70, 100 mol%) of 4,4-bis phenoxy pentanoic acid unit (diphenolic acid; DPA) units were synthesized and characterized by (1H and 13C)-NMR, MALDI-TOF MS, FT-IR, DSC and DMA analyses. The microstructural analysis of the copolymers, obtained by 13C-NMR using an appropriate statistical model, shows a random distribution of copolymer sequences, as expected. The presence of different amount of DPA units along the polymer chains affects the chemical and physical properties of the copolymers. The Tg and the contact angle values decrease as the molar fraction of DPA units increases, whereas the hydrophilicity increases. NMR and MALDI-TOF MS analyses show that all polymer chains are almost terminated with hydroxyl and chlorine as end groups. The presence of cyclic oligomers was also observed by MALDI-TOF MS analysis.