Synthesis Of Functional Styrene-Acrylate Emulsion And Application Of Paper Cultural Relics Protection

Functional styrene-acrylic emulsion polymer contains hydroxyl groups on the side chains,which has good affinity with paper fibers.Dipping on paper can significantly coat and increase fiber diameter,thereby improving the mechanical properties of paper,delaying aging and prolonging life.This paper studied on synthesis of functional styrene-acrylic emulsion and its application on protection of paper relics.In this paper,water as the disperse phase,styrene?BT?and butyl methacry-late?BMA?as the main monomers,hydroxyethyl methacrylate?HEMA?as functional monomer,alkane Polyoxyethylene ether?OP-10?and sodium dodecyl sulfate?SDS?as emulsifiers,and sodium bicarbonate?NaHCO₃?as an acid-base regulator,ammonium persulfate??NH₄?₂S₂O₈?as initiator.The functional styrene-acrylic emulsion was synthesized and apply it to paper heritage protection.The infrared absorption spectrum,relative molecular weight,and particle size of the polymer were measured by FT-IR,GFC and particle size analyzer respectively.The effects of emulsifier amount,emulsifier ratio,emulsification time,emulsifica-tion temperature,main monomer ratio,functional monomer mass,initiator dosage,reaction time and reaction temperature on the properties of styrene-acrylic emulsions were discussed.The optimal process conditions were determined:m?OP-10?:m?SDS?=1.0:1.0,T?emulsification temperature?=65°C,t?emulsification time?=30 min,m?ST?:m?BMA?=0.6:1.0,T?reaction temperature?=75°C,t?reaction time?=1.5 h,w?total emulsifier?=2.0%,w?HEMA?=7.5%,and w??NH₄?₂S₂O₈?=1.5%?all were rela-tive to the total monomer quality?.Orthogonal tests were designed to examine the relationship between different factors and property,relationship between various factors:initiator dosage>HEMA amount>reaction time>emulsifier ratio>reaction temperature>emulsion temperature>emulsifier amount>emulsification time>ST/BMA ratio.The relationship between the molecular distribution coefficient of functional styrene-acrylic emulsion polymer and the strength of coated rice paper was studied by gel chromatography.It showed that the smaller the distribution coefficient of the polymer molecule,the better the paper strength performance after dipping the emulsion.The functional styrene-acrylic emulsion was used on rice paper,and the single-factor experiment was used to determine the optimum application conditions:the emulsion quality was 5.0%and the drying temperature was 85°C.Under this condition,the mechanical properties of the rice paper had been significantly improved and the appearance was slightly reduced.Rrice paper had a greater increase in mechanical properties.The tensile strength increased by 1.24 kN/m,the folding endurance increased 88 times,the tearing degree increased by 72.1 mN,the gloss decreased by 0.4,and the whiteness decreased by 2.9.The mechanical performance of A4 paper,old books and old newspapers had also been greatly improved.The SEM also showed that the diameter of rice paper fibers after dipping was increased,and the fibers were crosslinked with each other.The experiment shown that the functional styrene-acrylic emulsion film had certain resistance to thermal aging and ultraviolet light aging.After aging,the film did not change significantly.After thermal aging,the mechanical properties of coated rice paper had not changed significantly.The two-component and three-component compounding experiments of emulsion,polyvinyl alcohol?PVA?and carboxymethyl cellulose?CMC?were conducted to determine the optimal binary compounding ratio.w?emulsion?:w?PVA?=5.0%:2.0%,the tensile strength of rice paper increased by 1.79 kN/m,the folding endurance increased by 250 times,the tearing degree increased by 73.5 mN.w?emulsion?:w?CMC?=5.0%:0.3%,the tensile strength of rice paper increased by1.01 kN/m,the folding endurance increased by 124 times,the tearing degree increased by 58.8 mN.Ternary compounding ratio,w?emulsion?:w?PVA?:w?CMC?=5.0%:2.0%:0.2%.The tensile strength of rice paper increased by 1.44 kN/m,the folding endurance increased by 221 times,the tearing degree increased by 70.5 mN.