Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved signifi...Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly occurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Gin. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.展开更多
This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium do...This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium dodecyl sulfate） into the HANR （high-ammoniated natural rubber latex） and followed by centrifugation. It was found that DPNR was successfully prepared with the lowest nitrogeneous content about 0.034±0.01% w/w by adding SDS for 1.00 phr and centrifugation at 12,000 rpm. Then DPNR was grafted with styrene and methyl methacrylate （DPNR-g-S/MMA） obtained by emulsion polymerization. The effects of DPNR-g-S/MMA were studied by varied the amount of SDS and redox initiator. From this result the grafting efficiency DPNR-g-S/MMA was higher than that of NR-g-S/MMA. The DPNR-g-S/MMA was used as an impact modifier in S-co-MMA sheet. Furthermore, the appropriate quantities of styrene monomer and DPNR-g-S/MMA were also investigated. While DPNR-g-S/MMA was used as impact modifier in S-co-MMA sheet, the result was shown DPNR-g-S/MMA improve impact strength of S-co-MMA sheet. Scanning electron micrographs of S-co-MMA sheet with DPNR-g-S/MMA was found the smooth fracture surface. Thus impact strength of S-co-MMA/gDPNR sheet was high and physical properties of S-co-MMA/gDPNR sheet could be able to be accepted in industry. Concisely, DPNR-g-S/MMA can be used as an impact modifier in S-co-MMA sheet.展开更多
基金This project is supported by Natural Science Foundation of College of Jiangsu Province , China (02KJA540001)
文摘Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly occurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Gin. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.
文摘This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium dodecyl sulfate） into the HANR （high-ammoniated natural rubber latex） and followed by centrifugation. It was found that DPNR was successfully prepared with the lowest nitrogeneous content about 0.034±0.01% w/w by adding SDS for 1.00 phr and centrifugation at 12,000 rpm. Then DPNR was grafted with styrene and methyl methacrylate （DPNR-g-S/MMA） obtained by emulsion polymerization. The effects of DPNR-g-S/MMA were studied by varied the amount of SDS and redox initiator. From this result the grafting efficiency DPNR-g-S/MMA was higher than that of NR-g-S/MMA. The DPNR-g-S/MMA was used as an impact modifier in S-co-MMA sheet. Furthermore, the appropriate quantities of styrene monomer and DPNR-g-S/MMA were also investigated. While DPNR-g-S/MMA was used as impact modifier in S-co-MMA sheet, the result was shown DPNR-g-S/MMA improve impact strength of S-co-MMA sheet. Scanning electron micrographs of S-co-MMA sheet with DPNR-g-S/MMA was found the smooth fracture surface. Thus impact strength of S-co-MMA/gDPNR sheet was high and physical properties of S-co-MMA/gDPNR sheet could be able to be accepted in industry. Concisely, DPNR-g-S/MMA can be used as an impact modifier in S-co-MMA sheet.
