摘要
Blends of biodegradable copolymer based on starch, poly lactic acid (PLA), poly vinyl alcohol (PVA) and natural rubber (NR) have been prepared. Gamma radiation induced synthesis and modification of polymer hydrogel was studied. The polymer blends have been chemically surface modified by glycerol. The modified polymer blends have been investigated for swelling ratio, tensile strength and 9 scanning electron microscopy. The swelling ratio of polymer blends increased significantly after surface modification with glycerol. The swelling of polymer was decreased as a function of (NR) content in polymer blends. The gel fraction (PVA-starch-PLA) and (PVA-starch-NR) blends increased by increasing the radiation doses (kGy) to reach the maximum amount of (~99%) and (~88.2%), respectively. Addition of 2.5% (PLA) led to greater increase of the swelling ratio than 10% (NR) to blends and the maximum swelling was found at dose (5 kGy). At concentration of glycerol (5.0% w/w), tensile strength decreased and elongation at break % increased. The polymers degrading microorganisms were isolated from soil samples. The degradation ability of the microbial isolates for each polymeric material was tested on agar plates. Among these isolates, the most efficient degrader isolates for prepared blends in MSM shaking flasks were selected and the degradation was confirmed by scanning electron microscopy.
Blends of biodegradable copolymer based on starch, poly lactic acid (PLA), poly vinyl alcohol (PVA) and natural rubber (NR) have been prepared. Gamma radiation induced synthesis and modification of polymer hydrogel was studied. The polymer blends have been chemically surface modified by glycerol. The modified polymer blends have been investigated for swelling ratio, tensile strength and 9 scanning electron microscopy. The swelling ratio of polymer blends increased significantly after surface modification with glycerol. The swelling of polymer was decreased as a function of (NR) content in polymer blends. The gel fraction (PVA-starch-PLA) and (PVA-starch-NR) blends increased by increasing the radiation doses (kGy) to reach the maximum amount of (~99%) and (~88.2%), respectively. Addition of 2.5% (PLA) led to greater increase of the swelling ratio than 10% (NR) to blends and the maximum swelling was found at dose (5 kGy). At concentration of glycerol (5.0% w/w), tensile strength decreased and elongation at break % increased. The polymers degrading microorganisms were isolated from soil samples. The degradation ability of the microbial isolates for each polymeric material was tested on agar plates. Among these isolates, the most efficient degrader isolates for prepared blends in MSM shaking flasks were selected and the degradation was confirmed by scanning electron microscopy.
