Study Of Chitin Gel/Oxidized Starch Bifunctional Natural Latex Fillers

Currently,impregnation rubber products,such as medical gloves,hoses and balloons,accounted for 60 percent of global production of natural rubber latex.The special application and the craftsmanship of impregnation rubber products show an inevitable limitation on the blending and application of filler and the requirement to high performance of impregnation rubber were increasing.For the problem of poor mechanical properties and poor antibacterial property of impregnation rubber products,chitin gel/oxidized starch bifunctional natural latex fillers and chitin/starch/rubber composite were prepared via ultrasonic treatment and latex compounding method and were characterized by fourier transform infrared spectroscopy(FT-IR),thermogravimetry(TG),scanning election microscopy(SEM),atomic force microscope(AFM)and dynamic light scattering(DLS).These Characterization methods were employed to study the morphology and structure ultrasound modified chitin gels(UCG),chitin gel/oxidized starch filler and chitin/starch/rubber composite.Development of microstructure,size distribution,stability of UCG and the effect of bifunctional fillers on natural rubber’s mechanical strength and antibacterial properties were investigated.The self-assembly of UCG and interface interaction between UCG and oxidized starch and between bifunctional fillers and natural rubber were also investigated.The results showed that:(1)The results of FTIR,XRD and TG showed that hydrogen bonding network of UCG was restructured by ultrasonic treatment.After 30 min of treatment,crystallinity and thermostability were decreased significantly and then were increased slightly.The results of SEM,AFM and size distribution showed that the gel was transformed to nanoparticle after 150 min of treatment and then was changed into nanofiber after 270 min of treatment.After 150 min of treatment,the size of gel was decreased obviously.The average particle size was 9.1 μm and nanoparticle content was 39%.(2)The bifunctional fillers were formed by hydrogen-bond interaction between UCG and oxidized starch and average particle size was decreased from 6.70 μm to 5.53 μm.With the increasing concentration of UCG,the fine structure on the surface of bifunctional fillers were changed obviously from globular to flocculent and to schistose.In case of 0.75%UCG,the area adsorbed layer of bifunctional fillers was about 5%.The mechanical stability of bifunctional fillers rubber latex was 651 s implying good consistency between bifunctional fillers natural and rubber.(3)The results of FTIR and SEM showed strong interaction between bifunctional fillers and rubber,which was chemical bonded.The tensile property of chitin/natural rubber,oxidized starch/natural rubber and chitin/starch/rubber compound implied that the globular,flocculent and schistose fine structure on the bifunctional fillers increased the interaction between fillers and rubber.The selected preparation conditions were determined,i.e.titanate coupling agent amount 0.5%,ultrasound modified chitin gel amount 0.75%and oxidized starch emulsion amount 10%and showed good mechanical property.(4)Compared with chitin gel,the UCG showed better antibacterial property against staphylococcus aureus and the bacteriostatic ratio was about 99%.The chitin/starch/rubber composite showed good antibacterial property against Escherichia Coli and staphylococcus aureus with increasing amount of composite fillers.