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In this paper, interpenetrating polymer networks (IPNs) based on poly(vinyl alcohol) (PVA) and poly(dimethylsiloxane) with terminal vinyl groups (PDMS-vinyl) with both hydrophilic and hydrophobic features were prepared by radical reticulation. Specifically, an aqueous PVA solution was mixed with an alcoholic PDMS-vinyl solution in the presence of 2,2-dimethoxy-2-phenylacetophenone (DMPAP) and N',N-methylenebisacrylamide (MBA) as initiating and reticulating agents, respectively, to obtain samples with the following PVA/PDMS-vinyl (w/w) compositions: 100/0, 75/25, 50/50, and 25/75. Confirmation of the IPN formation was done by a set of techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), differential scanning calorimetry (DSC), as well as theoretical calculations. The techniques used showed evidence of cross-linking reactions occurring in both PVA and PDMS-vinyl. Swelling experiments showed a proper balance of the resulting IPNs in swelling polar and apolar solvents, according to their composition and cross-linking. Tools of Theoretical Chemistry (Methods of Molecular Mechanics and Quantum Mechanics) were employed for the first time to investigate the cross-linking reaction between PVA and MBA and corroborate the experimental results. The PVA/PDMS IPNs showed a high capacity (up to 80 wt.%) to absorb water and may be characterised as hydrogels. [ABSTRACT FROM AUTHOR]

This work has investigated two routes of synthesising polymers containing L-histidine using maleimide chemistry; grafting of histidine onto an ethylene-alt-maleic anhydride copolymer and AIBN (azobisisobutyronitrile) initiated radical polymerisation of the monomer maleoyl-L-histidine. The grafting technique and monomer synthesis are utilising the maleimide formation between the primary amine of histidine and maleic anhydride. The reactions are conveniently carried out in one step with good yields. The copolymers containing L-histidine were prepared by reacting L-histidine or L-histidine methyl ester with poly(ethylene-alt maleic anhydride) in DMSO at 50 °C for 8-16 h with 80% yields independent of the degree of substitution. The monomer maleoyl-L-histidine was synthesised by reacting histidine and maleic anhydride in acetic acid and the monomer was subsequently polymerised by AIBN radical initiation in DMSO at 80 °C for 48 h to yield poly(N-histidyl maleimide). The resulting polymer had a different optical rotation ([α] = −11) than the monomer ([α] = +25), which is ascribed to the threo-diisotactic and/or threo-disyndiotactic stereoregularity of the polymer. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this work, the kinetics and mechanism of free-radical polymerisation of glycidyl methacrylate (GMA) using potassium peroxydisulphate (PDS) as water soluble initiator in the presence of synthesized 1, 4-Bis (tributyl methyl ammonium) benzene dichloride (TBMABDC) as multi-site phase transfer catalyst (MPTC) was studied. The polymerisation reactions were carried out under inert and unstirred conditions at constant temperature of 60 ± 1°C in cyclohexane/water biphase media. The role of concentrations of monomer, initiator, catalyst and volume fraction of aqueous phase, solvent polarity and temperature on the rate of polymerisation (Rp) was ascertained. The order with respect to monomer and initiator was found to be unity. The order with respect to catalyst was found to be 0.51. The rate of polymerisation is independent of ionic strength and pH of the medium. However, an increase in the polarity of solvent has slightly increased the Rp value. Based on the results obtained, a suitable kinetic scheme has been proposed to account for the experimental observations and its significance discussed. [ABSTRACT FROM AUTHOR]

The multi-sited phase transfer radical polymerisation of acrylonitrile (AN) with newly synthesized and characterized 1, 4-Bis (tributyl methyl ammonium) benzene dichloride (MPTC) was investigated in K2S2O8 aqueous-organic two phase system at 60 ± 1 °C under nitrogen atmosphere. The role of concentrations of monomer, initiator, catalyst, temperature, acid and ionic strength on the rate of polymerisation (Rp) was ascertained. The order with respect to monomer, initiator and multi-site phase transfer catalyst were found to be 0.5, 1.0 and 0.5, respectively. A suitable kinetic scheme has been proposed to account for experimental observations and its significance. The prepared polymer was characterized by FT-IR and XRD analysis. [ABSTRACT FROM AUTHOR]