Studies On The Polyacrylate Sizes Prepared With Emulsion Polymerization

The paper studies on the preparation of emulsion polymerized polyacrylate sizes and evaluate the sizing properties of the reaction products. The main aim of the study is to overcome the objection of the widely used warp sizes at present.After referring to literature about the polyacrylate sizes and its preparation, the emulsion polymerization and semi-continue process are selected as the technologic method. The effect of preparation technique on the stability and residual monomers of the sizes were studied. The best preparation technique is obtained as follows: emulsifiers 2.5% to monomer by weight, reaction temperature 75℃and reaction time 3.5h, initiator 1.0% to monomer by weight. And the emulsifier dosage is found to be the most important factor to the stability and monomer conversion.Furthermore, the effects of the chief preparation parameters on size properties were also studied. Experiments have indicated that temperature, time, and the amount of the emulsifier and initiator have significant impact on the viscosity and adhesion property. While the size mixture with low content of PA, the adhesion performance of polyacrylate sizes is lower than PVA. However, when the PA content reduces to 25% by weight, polyacrylate sizes is superior to PVA. With polyacrylate sizes instead of PVA gradually, the properties of the size and size film are improving.The paper also studies on function of acrylonitrile unit incorporated into the polyacrylate sizes. The result shows that compared with structural unit of methyl methacrylate, acrylonitrile unit has more advantages to enhance sizing property of polyacrylate and reduces size cost.