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The synthesis of injectable hydrogel material from glycidyl methacrylate grafted poly (vinyl alcohol), PVA-g-GMA, used for meniscus tissue engineering was studied. Effect of glycidyl methacrylate (GMA) content on %grafting of PVA-g-GMA is reported. The successful grafting of GMA onto PVA was confirmed by Nuclear Magnetic Resonance (NMR) and Fourier transform infrared (FTIR). PVA-g-GMA injectable hydrogels were fabricated through photocrosslinking with UV light. Hydrogel fabricated parameters, including PVA-g-GMA concentration, photo-initiator concentration, and irradiation time on the gel fraction and swelling ratio were studied. It was found that the PVA-g-GMA content showed a strong effect on the gel fraction and swelling ratio. With increasing PVA-g-GMA concentration from 2.5%w/v to 7.5%w/v, the gel fraction increased from 60 % to 82 %. [ABSTRACT FROM AUTHOR]

In this research, microcrystalline cellulose reinforced photo crosslinked thermoplastic starch was studied to replace petroleum-based polymers on bioplastic application. There are 3 stages in this research. The first stage will be to find the optimum formulation of microcrystalline cellulose where the variation of the amount of filler carried out in this research is 0 %, 3 %, 6 %, 9 % and 12 % of the dry weight of starch. The second stage will be to find the optimum crosslinking time using photo crosslinking where the properties of irradiated thermoplastic starch for every 0, 2, 4, 6 and 8 hours. The third stage will be to compare the properties of photo-crosslinked thermoplastic starch and peroxide crosslinked thermoplastic starch. Each formulation has undergone tensile test to study their mechanical properties and the optimum formula is obtained for subsequent studies. 6 % microcrystalline cellulose filled thermoplastic starch films was found to have the highest tensile strength and was chosen to be photo-crosslinked for the next objective. Results showed that 8 hours of photo-crosslinking time has the highest tensile strength, so this specimen is further compared with 8 hours of peroxide crosslinked specimen where peroxide crosslinked thermoplastic starch films exhibit higher tensile strength than thermoplastic starch film that is photo-crosslinked for 8 hours. [ABSTRACT FROM AUTHOR]

Inorganic-organic hydrogels based on dimethacrylated polydimethylsiloxane (PDMSMA) and diacrylated poly(ethylene glycol) (PEGDA) macromers were prepared via photocrosslinking method. Silane coupling agent was incorporated into the hydrogel formulations to overcome the phase incompatibility. Pure PEGDA (0:100) hydrogels showed the highest value of ESR %, while pure PDMSMA (100:0) hydrogels showed no swelling as we expected. Inclusion of more hydrophobic domains resulted in a lower value of ESR %, i.e. in 75:25 hybrid hydrogels. Beside, we had noticed 50:50 and 75:25 hybrid hydrogels disintegrate during swelling period. However, their integrity was improved and sustained after the coupling agent was added. Similarly, the value of E* for the hybrid hydrogels showed an increment after the coupling agent was incorporated, and this is in a good agreement with the SEM micrograph which display an improved interfacial adhesion. [ABSTRACT FROM AUTHOR]