Synthesis and fabrication of ultrafiltration membranes from homo and blend polymers of novel combination of cyclic amides/ imides to norbornene/ oxonorbornene; shift from classic oligomers to high performing polymer materials.

Controlled release of active chlorine into the water system through membrane bound disinfectant, prevention of biofilm formation at the membrane surface and killing of antibiotic resistant bacteria were the study objectives that were accomplished in presented work. Cyclic amines/amides/imides are effective precursor of N-halogenated amines/amides/imides. Such N-halogenated compounds are found to be effective against antibiotic resistant bacteria such as, E. coli and S. aureus. Henceforth cyanuric acid and 5,5-dimethyl hydantoin were selected as representative precursor of such amide/imides that could be halogenated and provide antimicrobial performance. The polymer PES was introduced with side chain of primary amine. Further this primary amine was converted to secondary amine with novel modification containing cyanuric chloride. It was further modified to cyanuric acid as a desired precursor of N-halamide/imide. The PES-modified -cyanuric acid (PESmCA) was characterized using IR, NMR, XRD and SEM. While two novel monomers containing hydantoin as a branch extending from the ethyl group chain; belonging to norbornene dicarboximide and oxonorbornene dicarboximide, were successfully synthesize and characterized using IR, NMR and HRMS techniques. Further these monomers were polymerized via ring opening metathesis polymerization reaction into novel polymers of P(NDH) and P(ONDH). The polymer’s olefinic bonds were saturated to s-P(NDH) and s-P(ONDH). The unsaturated and saturated polymers were characterized through IR, NMR, and SLS techniques. The saturated polymers and the modified PES were fabricated into membranes and characterized via SEM and contact angle measurement. The membrane performance tests were conducted using pure water permeance and BSA protein rejection tests. The membranes were chlorinated and rinsed to remove adsorbed active chlorine. The rinsed membranes were characterized with IR providing respective N-Cl peak in range of 721-719 cm-1. The unwanted chlorine release into the water assembly was not observed provided that the respective polymers had covalently stable cyclic N-Cl moieties. Membranes were challenged against 106CFU/ml of bacteria (E.coli and S.aureus) in static agar test and dead end filtration tests. The membranes provided 100% inhibition of bacteria E. coli and S. aureus upon surface contact in agar plate test. The respective membranes were also suitable for dead end filtration pressure assisted bacterial flow test. The test provided 99-100 % kill of both bacteria. These N-halamide/imide novel polymer and modified polymer systems were efficiently chlorinated through repeated cycles. Keywords: Modified PES, norbornene polymers, oxonorbornene polymers, ROMP, controlled release of active chlorine, biofilm prevention, inhibition of antibiotic resistant bacteria, phase inversion, UF membranes.