Synthesis, characterization, microstructure determination, thermal studies of poly (N-vinyl pyrrolidone-maleic anhydride-methyl methacrylate)

Development and evaluation of antimicrobial PVC-grafted polymer for enhanced paint applications

Demand for antimicrobial paints is increasing globally due to the rising need to control microbial growth and reduce infection risks in various environments. This increased demand underscores the crucial role of advanced antimicrobial coatings in promoting health and safety. In this context, an innovative poly(vinyl chloride) (PVC) grafted polymer with 1-(2-aminoethyl piperazine) (AEP) was prepared and studied in detail. In this study, the prepared polymer was characterized using FTIR and NMR spectroscopy to examine the polymer's chemical structure and employed TGA and DSC for thermal stability analysis. The antimicrobial activity of the grafted polymer was evaluated through the agar diffusion method and showed a significant inhibition zone of 21.6 mm for S. aureus, 16.3 mm for E. coli, 18.3 mm for M. smegmatis, and 20.3 mm for C. albicans at a lowest concentration of 12.5 μg mL-1. To assess surface characteristics, the PVC-g-AEP polymer was mixed with commercial paint and applied to a glass surface. SEM and AFM analysis showed a 5-times increase in porosity while maintaining visual aesthetics. Additionally, the paint displayed excellent stability against water, retaining around 90% of its antimicrobial activity even after 15 washes. This advanced polymer not only exhibits superior antimicrobial properties but also improves paint durability, setting a new benchmark for high-performance antimicrobial coatings and significantly advancing protective paint technology.

Piperazine based antimicrobial polymers: a review

Microbial infections are a life threatening concern in several areas, which include the biomedical sector, healthcare products, water purification systems, and food packaging. Polymers with low molecular weight bioactive agents or disinfectants help the scientific community to reduce the lethality rate caused by pathogenic microbes. Antimicrobial polymeric approach is one of the advanced approaches made by researchers in concern with the problems associated with small molecules that restrict their applications in broad spectrum. History reveals the synthesis of numerous antimicrobial polymers using various antimicrobial agents but lacks the use of piperazine molecule, which is of pharmaceutical importance. This review gives an insight into the current and future perspective for the development of piperazine-based antimicrobial polymers.

Phenylalanine-Tethered pH-Responsive Poly(2-Hydroxyethyl Methacrylate)

A series of pH-responsive random copolymers comprised of 2-hydroxyethyl methacrylate (HEMA) and tert-butyl carbamate (Boc)-protected phenylalanine methacryloyloxyethyl ester (Boc-Phe-EMA) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization in N,N'-dimethylformamide (DMF) at 70 °C. The synthesized copolymers were comprehensively characterized using a combination of techniques, including ¹ H NMR, FT-IR spectroscopy and size exclusion chromatography (SEC). Reactivity of each monomers towards controlled radical polymerization was evaluated by determining the reactivity ratios by virtue of extended Kelen-Tüdös method at high conversions revealed the higher reactivity of non-modified HEMA (r_HEMA =1.03) in contrast to Boc-Phe-EMA (r_Boc-Phe-EMA =0.48). Furthermore, the expulsion of the Boc-groups resulted copolymers with ionizable pendant primary ammonium and hydroxyl groups. To understand the glass transition behaviours of homo- and co-polymers, differential scanning calorimetric (DSC) measurements were carried out. The effect of HEMA content on the pH-sensitivity of the copolymers in aqueous medium was investigated through turbidity measurements. Finally, the counteranion exchange from trifluoroacetate to chloride provided copolymers with enhanced water solubility and unaltered phase transition pH.