Study On The Modification Of Cellulose Acetate Butyrate

Cellulose acetate butyrate (CAB) is product of esterification by natural fiber. As CAB has features in preferable water resistant, weather resistant, flexility, high transparency and can stabilize the orientation arrangement of the metal, so it could apply in kinds of wood coating, glass coating, plastic coating and transparent varnish as main film former. But the CAB coating is so soft and the solvent-resistance and the scratch-resistance are not so excellent. Besides, it may cost so large amount of solvents to form film that it is unfavorable to environment. So it is necessary to modify the CAB.In this paper, firstly, the acrylate grafted with CAB could be prepared by solution polymerization as a water-soluble resin. The product could effectively improve the service performance of the CAB coating and many factors such as initiator content, the ratio of soft/hard monomer, reaction temperature, etc, on the polymerization and property of product were discussed. The results show that the CAB modified by acrylates could be favorably prepared and the conversion rate of monomers is greater than 96%, when the continuous feeding is used, the reaction temperature is 85℃, the stirring rate is 150r/min~200r/min and the reaction time is 3h. When the content of acrylic acid is 12%, the ratio of soft/hard monomer is 1:1.5, it could get the best properties of the modified resin. The hardness could reach 4H from H, the adhesion to glass is zero degree from four degree and the coating is highly transparent and excellently water-soluble.Besides, to make full use of the open-loop behavior of the maleic anhydride, the maleic anhydride grafted with CAB is synthesized in homogeneous system. The modified resin is crosslinked and then a non-solvent, 100% solid content UV-cured coating is obtained. The results show that under the suitable proportion of reactive diluents, the hardness, the adhesion to glass and the solvent-resistance of the UV-cured modified-CAB coating are respectively 4H, 0 degree and more than 400 times. Moreover, the waterborne UV-cured resin is also received. When SR610 reaches at a certain proportion, a water-resistant 96h coating could be obtained.