Preparation And Properties Of Graft Copolymerization For Carboxymethylcellulose

CMC is a product of biological degradation , no-toxicity, salt-resistance, regeneration and inexpensive. As for the modification of CMC graft copolymerization, we can endow it with some new properties while virtues which CMC inhered with can't be destroyed. This paper studies the reaction of CMC-AM graft copolymerization which has taken the main reactive part as CMC or AM respectively, the conditions of graft copolymerization and initiation systems, and some monomers grafted onto CMC. It is fully approved the construction of polymers by means of the FT-IR analysis, thermal analysis, X-ray diffraction analysis and so on. This paper also researches the properties of graft copolymers.The reaction of graft copolymerization initiated by (NH4)2S2O8-Na2SO3 , which has the main reactive part of AM and minor reactive part of CMC, has studied the reaction conditions. The results show that the optimal reaction conditions should be: the reaction compound concentration is 20%; the initiator concentration is 300mg/L; the initial temperature is 40℃; the initial pH value is 8. The priority of the effects is: the initial pH value, the initiator concentration, the reaction compound concentration, the initial temperature. The experiences approve that at the ratio of CMC is 10% and the optimal reaction conditions, we can get the best molecular weigh of 8.03×106 and the degree of grafting achieved the best value of 845.6% as well, which is similar with the theoretical value of 900%.So we can conclude that the effect of graft is very well.We study the initiation systems of the graft reaction which has the main reactive part of CMC and the secondary reactive part of monomers, and get the optimal initiation system: [H2SO4] 0.02mol/L,[KMnO4] 3.0×10-3 mol/L.We also get some other conclusions: under the monomer concentration of 7%, initiation system of H2SO4-KMnO4 has the best initiation effect, but (NH4)S2O8-Na2SO3 has the best initiation effect above the monomer concentration of 7%. Meanwhile, we initiate the graft copolymerization by means of mixed initiations: (NH4)2S2O8-Na2SO3 ([(NH4)2S2O8] 300mg/L,[Na2SO3] 300mg/L)and H2SO4-KMnO4([H2SO4] 0.02mol/L.[KMnO4] 3.0×10-3 mol/L),the result shows that the effect of mixed initiations has dobetter than simple initiation of H2SO4-KMnO4.As for other monomers grafted onto CMC, vinyl acetate and ethylenediamine are not suitable to graft onto CMC, while some other allyl monomers, the priority of the effects is acrylamide, sodium acrylate, methyl acryalate.We study the properties of graft copolymers and have verified that the salt-resistance and heat-resistance of graft copolymers have improved remarkably than CMC or PAM alone. According to the properties of viscosity, radius of gyration and conductivity, we have achieved the best components,which the ratio of CMC is 15% and the hydrolysis degree of graft copolymer is 15%.