Poly(butylene succinate) (PBS) with different molecular weights was irradiated using an electron beam (EB) in the presence of polyfunctional monomers at ambient temperature. Five polyfunctional monomers were used in this work. The highest amount of gel fraction was achieved when PBS was blended with trimethallyl isocyanurate (TMAIC). The amount of TMAIC introduced strongly influenced the amount of resulting gel. It was determined that the crosslinked PBS sample containing 1% TMAIC had a higher glass-transition temperature than did the original PBS. It was also observed that the presence of crosslinking bonds in the irradiated PBS greatly improved its heat stability and diminished its ability to biodegradate. Accordingly, it can be concluded that crosslinked PBS in the presence of TMAIC significantly improved its heat resistant properties.

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Batik wastewater, in general, is colored and has high concentrations of BOD (biological oxygen demand), COD (chemical oxygen demand), and dissolved and suspended solids. Polysulfone (PSf)-based membranes with the addition of polyvinyl pyrrolidone (PVP) were prepared to treat batik industrial wastewater. PSf/PVP membranes were prepared using the phase inversion method with N-methyl-2 pyrrolidone (NMP) as the solvent. Based on the membrane characterization through FESEM, water contact angle, porosity, and mechanical tests showed a phenomenon where the addition of PVP provided thermodynamic and kinetic effects on membrane formation, thereby affecting porosity, thickness, and hydrophilicity of the membranes. The study aims to observe the effect of adding PVP on polysulfone membrane permeability and antifouling performance on a laboratory scale through the ultrafiltration (UF) process. With the addition of PVP, the operational pressure of the polysulfone membrane was reduced compared to that without PVP. Based on the membrane filtration results, the highest removal efficiencies of COD, TDS (total dissolved solid), and conductivity achieved in the study were 80.4, 84.6, and 83.6%, respectively, on the PSf/PVP 0.35 membrane operated at 4 bar. Moreover, the highest color removal efficiency was 85.73% on the PSf/PVP 0.25 operated at 5 bar. The antifouling performance was identified by calculating the value of total, reversible, and irreversible membrane fouling, wherein in this study, the membrane with the best antifouling performance was PSf/PVP 0.25.

Summary: Isolation of a-cellulose from rice straw has been successfully carried out having 26.95% yield, with 74.28% crystallinity index. The a-cellulose is then chemically modified by grafting acrylic acid monomer onto cellulose using preirradiation graft copolymerization technique. The optimum condition for grafting is obtained at 30 kGy radiation doses, 10% monomer concentration, 60 C grafting temperature and 120 min reaction time, with 84.12% grafting average. The infrared spectroscopy showed a new absorption band at 1720 cm À1 in the modified cellulose, which can be attributed to the presence of carbonyl group of acrylic acid. FESEM imaging showed that the acrylic acid grafting leads to an increase in the roughness and width of the cellulose. The grafting process was found to increase final decomposition temperature of the fibers.

RADIATION YIELD AND RADICALS PRODUCED IN IRRADIATED POLY(BUTYLENE SUCCINATE).The main chemical effects of ionizing irradiation on polymers are crosslinking and chain scission. Both processes occur simultaneously and their yields determine the final results of processing. The radiation yield of crosslinking could be determined by several methods depending on the characteristics of the material and properties of the gel. Radiation parameters of gelation, such as gelation dose and ratio of scission yield to crosslinking yield, as well as their values were estimated. In this study, those parameters depend on the amount of Trimethallyl isocyanurate (TMAIC) in Poly(butylene succinate) (PBS), molecular weight of PBS, and irradiation condition. In the absence of TMAIC, higher molecular weight of PBS required less energy to start gelation process compare to lower molecular weight of PBS. While in the presence of TMAIC all of the PBS samples require similar energy to start gelation process. The existence of macroradicals were observed by Electron Spin Resonance measurements. The result showed that the spectra consisted of signals derived from radicals on carbon nearby carbonyl, and signals derived from radicals on carbon reside between two similar carbon on polymer, both of radicals lead to crosslinking.