Synthesis Of Grafted Copplymer Of Cationic Chitosan And Its Appllication On Paper

Chitosan is a production of the chitin part takes off acetyl-group, chitin is the second amyloses only next to cellulose broad exist in low grade animals such as crab, shrimp and in low grade plants such as alga, fungus. Its contents are extremely rich, nature output every year may amount to 10 tons . It has recently attracted great attention of numerous investigators in different countries because of its unique chemical and biological properties.The first part of this paper dealt with the factors affecting the preparation of 2-Hydroxypropyltrimethyl ammonium chloride chitosan (CTS-ETA). In order to obtain the optimum process conditions, the effects of some factors, such as dosage of etherifying agent, reaction time, reaction temperature or reaction ratio, degree of substitution ,were studied. The chitosan quaternary ammonium salt was characterized by fourier transform infrared spectroscopy (FTIR)Secondly, a copolymer was obtained from graft copolymerization of 2-Hydroxypropyltrimethyl ammonium Chloride Chitosan and acrylamide in nitrogen atmosphere by using ceric ammonium nitrate as redox initiator. It was found that the grafting percentage is 29.5%, viscosity is highter than 57mpas when the concentration of reaction temperature is 35℃, reaction time is 4h. The grafted copolymer was identified by FT-IR.In the third part, the effect of CTS-ETA on the physical properties, aging resistance properties and antibacterial activity of handsheets were studied in this part, the product with different DS and concentration was sprayed on the handsheets or internal added in the pulp respectively. The result showed that the properties of handsheets internal added by DS 1.015 and concentration of 0.2% CTS-ETA changed greatly, the tensile strength increased 15.7 %, the folding endurance increased nearly 54%, and the tearing index and bursting index increased 12.8% and 16.6% respectively. When the handsheets were treated by sprayed the tensile strength, folding endurance, the tearing index and bursting index increased 18.5%,29.7%,15.5%,18.8% respectively. Aging resistance could also be improved by treatment of CTS-ETA, but there is no influence on brightness and gloss.The effect of CTS-ETA on the antibacterial activity of handsheets was investigated. It was showed that the obtained quaternary ammonium salt of chitosan was water soluble and was of good antibacterial effect with low dosage. The handsheets which treated by internal added in the pulp with CTS-ETA (DS=1.015) at a concentration of 0.25% inhibit the growth of Gram negative bacteria ( Escherichia coli) and Gram positive bacteria ( S taphylococcus aureus).The inhibitory ratio to each of them is 63.5%,73.2%. The handsheets which treated by sprayed on the handsheets could inhibit the growth of S. aureus completely at a solution concentration of 0.25% (DS=1.015) and could inhibit 90% of E.coli's growth. The CTS-ETA definitely has an inhibitory activity against S. aureusa and E. coli.The CTS-ETA-g-AM can be used as paper strengthen agents. The experiments showed that they can improve the physical properties of handsheets made of softwood pulp. adding only 0.3% dosage of the derivates in the pulp the tensile strength, tearing index, bursting index and folding endurance increased 18.1%, 6.9%, 17.1% and 56%, respectively, CTS-ETA-g-AM (viscosity=57mpas) could inhibit the growth of E.coli and S.aureus significantly. The inhibitory ratio reached 29.4% and 57.8% for E. coli and S.aureus at a concentration of 0.3%.