Preparation Of Surface Sizing Agent And Its Application In High-Grade Automobile Filter Paper

The stiffness of automobile filter paper produced from natural plant fiber or other raw materials is low and its water-absorption is too strong,which can't meet the requirements of production and utilization of high-grade automobile filter paper.Therefore it is necessary for base paper to be applied surface sizing in order to improve its water resistance and other mechanical properties.The development of surface sizing agent from which base paper sized could acquire favorable hydrophobicity and high stiffness is a bottleneck problem domestic enterprises faced.By the means of polymer design,waterborne SAE,core-shell fluorine-containing emulsion and cationic fluorine-containing emulsion were prepared.After the filter paper was dipped sizing respectively,modern detection means were used to test and characterize the product properties.Through process optimization,the change of stiffness and water resistance were discussed and the impregnation mechanism was preliminarily studied.?1?Adopting pre-emulsified continuous drip polymerization,water-borne SAE was prepared.When m?SDS?/m?OP-10?=1:4,m?St?/m?BA?=60/40,emulsifier and initiator dosage were 4wt%,0.5wt%respectively,stirring rate was 250r/min,polymerization temperature was 75?,particle size distribution of the emulsion prepared concentrated between 87nm to92nm?PDI=0.047?.Its gel rate was 1.4%and the conversion rate reached98.5%.?2?Adopting pre-emulsified semi-continuous seeded polymerization,the fluorinated acrylate emulsion with high water resistance was prepared using dodecafluoroheptyl meth-acrylate?DFMA?as modified monomer.When emulsifier and initiator dosage were 0.6wt%,3.5wt%,DFMA dosage was 8.4wt%,m?OP-10?/m?SDS?=2/1,the emulsion particles had characters of obvious core-shell structure and centralized distribution?PDI=0.027?.The surface energy of latex film reduced to 23.1mN/m.The mechanical properties could be optimized by adjusting core/shell proportion of monomers.?3?The polymerizable cationic surfactant DMMB was synthesized,using dimethyl amine ethyl methacrylate?DM?and myristylbromide?MB?as materials.Analyzed by ¹HNMR,FT-IR and HPLC,the target product could be confirmed.Its purity reached 98.2%and CMC was 2.51×10^-3mol/L.DMMB was used with OP-10 as compound emulsifier to prepare fluorinated cationic surface sizing agent.The reaction kinetics of fluorine modified cationic surface sizing agent at different temperatures had been studied.The activation energy Ea was determined 25.23KJ/mol.?4?After the effect of heat treatment temperature,time and glue amount on paper sizing degree were discussed,the core-shell one was found to reach the best sizing degree among the three emulsions.The surface properties of papers impregnated by different sizing agents and conditions were studied by OCA,DSC-TGA,high-times optic microscope and XPS.These studies provided further theoretical foundation to study sizing mechanism and new sizing agent development.