Preparation And Application Of Polyacrylate And Its Composite Emulsion For Paper Sizing Agent

Regulating and controlling the structure and property of polymer relatively, nowadaysthe studies on the polymer are increasingly and extensively as the sources of monomers areflexibly varied. The raw materials, synthesis process, water resistance and film-forming ofpolyacrylate are easily available, simple and good. The polyacrylate emulsion can be impartedpositive charge after adding some substances with positive charge. The emulsions can beadsorbed onto the negatively charged surface of the paper fibers spontaneously and improvethe sizing effects effectively when acting as the sizing agents.In this research, the cationic polyacrylate copolymer emulsion which used as surfacesizing agent was prepared via the process of semi-continuous seed emulsion polymerization,in which the surfactant system was composed of cetyl trimethyl ammonium chloride (CTAC)and NP-10and methyl methacrylate (MMA), butyl acrylate (BA) were used as mainmonomers.The sized papers become good film by adding hydrophobic monomer-2-ethylhexylacrylate (2-EHA) in the study of polyacrylate polymerization. Meanwhile, to improvingadhesion of the polymer to the fibers and having good surface sizing effects, we adding a kindof cationic monomers-methacryloyloxy ethyl trimethyl ammonium chloride（DMC）. Itstudied the influence of emulsifier, initiator and functional monomers on the emulsionproperties, water-resistant and film-forming properties and so on. Optimization of thesynthesis conditions and the best results were obtained: The self-made sizing agents showbetter performance When CTAC:NP-10as emulsifiers and the ratio of1, DMC, AIBA,2-EHAdosage were5.0%l,1.6%,15%of the total. The structure and thermal decompositionbehavior of copolymers were tested by FT-IR and DSC respectively, the particle size and theirdistribution, the morphology of the latexes were tested by Malvern Nano-sizer and TEM. Thesurface morphology of the paper without and with surface sizing agent, were investigated byscanning electron microscopy (SEM), and the water resistant property of the sized paper wascharacterized by surface tension meter and Cobb value tester as well.In order to improve adhesion to the surface sizing properties, the introduction of DMC and a kind of cellulose-reactive monomer which functional groups can be reacted with the acrylate called methacrylateglycidyl (GMA). It studied the influence of initiator and functional monomers on the emulsionproperties and sizing effects. Experimental results: the emulsion properties and sizing effects arethe best when the dosage of AIBA, DMC and GMA is1.6%,5.0%and10%. Adding polymer binderwhich has strong adhesive and good film-forming ability called polyvinyl alcohol (PVA) to improve themechanical properties of the sized papers. The best results showed: the mechanical properties of sizedpaper can be improved by adding PVA. The mechanical properties of sized and the stability of emulsion arethe best when the dosage of PVA is2.39%.