Preparation Of The Flame-retardant Polymer Latex With Synergetic Effect Of Phorous And Silicon To Reinoforce Auto-filter Papers And Its Application

In this study, three ways including the change of the fiber compositions of the raw auto-filter papers, structural adjustment of the reinforcement polymer latex and the application of phosphorous-silicone synergetic effects for flame retardant action, were employed to improve the flame retardant properties of the auto-filter papers.Although the addition of the flame-retardant synthetic fibers could increase the LOI value of the paper, the formation of the paper, mechanical properties as well as evenness of the hybrid papers were decreased due to the hydrophobic surface and the absence of hydrogen bonds of the cylinder-shaped synthetic fibers. Therefore, a new method for preparation the synthetic pulp in the ethanol aqueous medium via trough-style pulp beater was employed in this work. Moreover, the influence of the factors during the pulping, such as the composition of the medium, slurry consistence, knife hanging load, beating time and etc., on the pulp dispersibility in the aqueous medium, specific surface area(SSA), morphological structure of the chopped fibers and the evenness of the hybrid papers were investigated by the methods of DCAT, SSA analyzer, FS-100 fiber structure analyzer as well as paper evenness analyzer. From the results, it was found that the SSA of the chopped fibers could be increased greatly after the pulping processed in the aqueous medium with 5% ethanol, whereas, the cylinder-shaped fibers was turned to be flat stripped ones, which changes in the morphological structure and SSA were supposed to facilitate the formation and evenness improvement of the hybrid papers.However, the mechanical strength of the hybrid papers was relatively pool even lower than the ones prepared by the mercerized wood pulp, owing to the chemical inert property of the synthetic pulp which led to decrease of the reinforcement by the styrene/acrylate copolymer latex on such hybrid papers. In this work, the crosslinkable polymer latex was fabricated via core/shell emulsion copolymerization to improve the mechanical properties of the hybrid papers. Besides, the influence of the dosage of the functional monomer, the composition of the surfactants as well as other copolymerization conditions on the stability of the copolymerization, adhesion of the copolymer and mechanical strength of the hybrid papers were discussed. It was concluded that the mechanical performance of the paper could be obviously improved when the dosage of the functional monomer, the composition of the surfactants as well as their content were set at a certain value. The impregnated paper exhibited excellent physic-mechanical strength, but they were flammable because of the flame-retardant property absence of the reinforcement copolymer materials.To improve the flame-retardant property of the reinforcement resin, a new styrene/acrylate copolymer containing phosphorus with better flame-retardant performance was developed by the method of core/shell emulsion copolymerization of the diethyl(acryloyloxyethyl)phosphonate and acrylics monomer. The flame-retardant functional monomer, diethyl(acryloyloxyethyl)phosphonate(DAEP),was prepared by the esterifaction reaction between phosphorus oxychloride and β-hydroxyethyl acrylate(HEA) in different solvent, such as methylene dichloride, ethyl acetate or ethyl ether. The influence of solvent and reaction temperature on the yields of the phosphorous compounds, their composition and the content of vinyl groups was investigated by the methods of FTIR, HPLC and iodometric method. It’s concluded that the yields and component of the final product could be tailored in some degree by the solvents. In this work, FTIR, Zeta-nanosizer, elemental analyzer, TGA and LOI measuring instrument were employed to characterize the chemical structure of the copolymers, the size and its distribution of the latex particles, the content of phosphorus, thermal decomposition and flam-retardant property of the copolymers. It was found that the content of phosphorus increased as increasing the dosage of polymerisable diethyl(acryloyloxyethyl)phosphonate monomer, which resulted in the improvement of flam-retardant property of the copolymer. When the content of phosphorus in the copolymer was increased up to 1.48%, the LOI value of the paper reinforced by the copolymer was high up to 24.9which is relatively higher than those reinforced by styrene/acrylate copolymers(their LOI value was only 20.5),Besides, the action of the synergistic effect of phosphorus and silicon on the flam-retardant property of the paper was primarily discussed as well. A kind of stable hybrid latex was prepared via emulsion copolymerization in presence of silicon dioxide in the core layer of the polymeric particles. However, the LOI value of the papers reinforced by such hybrid latex was a little bit higher than those reinforced by the polymeric emulsion containing phosphorous, which is attributed to the much lower dosage of silicon dioxide which limited to produce effective synergetic effect of phosphorous and silicon. Hence, much work needs to be done to facilitate the effect on improvement of the flame retardant property of the filter papers.This research not only shows great practical significance and theoretical value for the application of high-performance synthetic organic fibers in auto-filter papers, but also develops the positive exploration on the improvement of flam-retardant properties of auto-filter papers.