Study On Preparation And Performance Of The New Textile Size

At present, modified starch, polyvinyl alcohol(PVA) and polyacrylic acid size mixture are the three main sizes in the warp sizing. Because PVA was difficult to be biologically degraded, many countries call for "seldom or don't use PVA". The sizes in current application have a mass of PVA. Polyacrylic acid size has serious re-adherence. Starch size has poor gel performance and instable viscosity. It is very imperious to develop a new kind of sizes which have good performances, economic and environmental protection.Aiming at the existent problems, this paper proposed some solutions. Firstly, the polyacrylate size was synthesized by several monomers which had high ratio of performance to cost. Then the combined sizing was obtained by adding acetated starch size and PVA into the former size. The aim, reducing the usage of PVA, could be achieved through a series of experiments to adjust the mass of PVA in the combined size. The performances of the combined size could be improved by adding certain amount of nano-materials.Based on emulsion polymerization, the polyacrylate size was synthesized using acrylic acid, methyl acrylate, butyl acrylate and vinyl acetate as monomers, with sodium lauryl sulphate (SDS) and OP-10 as composite emulsifiers and potassium persulphate (KPS) as initiator. The optimum reaction conditions were determined, i.e., m(AA) : m(MA) : m(BA) : m(VAc) = 5:8:5:2, m(SDS) : m(OP-10) = 4:1, reaction temperature was 70℃in the N₂ atmosphere, NaHCO₃ as pH buffer to maintain the stabilization of emulsion, with mass ratio of composite emulsifiers and KPS to mixed monomers of 5% and 0.4%, respectively. The performaces of former synthesized polyacrylate size were improved, i.e., higher tensile strength, lower moisture absorption and better water-solubility. The combined size had the best performances when the mass ratio of polyacrylate size, acetated starch size and PVA size was 15 : 10 : 12.5. The content of the PVA in the combined size was 23% lower than that of the commercial size, and the combined size had better hairness and economic benefit. The performances of the combined size were improved after the addition of nano SiO₂,TiO₂ and Al₂O₃. It was observed that the combined size had the greatest performances improvement by adding 0.5% nano TiO₂.