The Preparation Of Acrylic Coatings And The Research Of Polypropylene-wollastonite Composites

This paper mainly includes two parts.The first part introduces the preparation of weathering acrylic coatings.The second part introduces the study of polypropylene-wollastonite composites.The weathering acrylic coating described in this paper is to add a suitable fluorine-containing monomer(hexafluorobutyl methacrylate)after a series of optimization of the traditional acrylic coating ratio.On this basis,Silica particles as a leveling agent for better use of the acrylic coating.We used the prepared coating coated on a stainless steel surface by a certain ratio.After testing the properties of the coating,it was found that the coating had good hydrophobicity,strong antifouling performance,excellent thermal stability,and good mechanical properties.The main contents include the following aspects:1.The experiment use n-butanol and butyl acetate as solvent,(MMA),hydroxyethyl acrylate,butyl acrylate(BA)as the main component,azobisisobutyl cyanide(AIBN)as the initiator,add a small amount of fluorine-containing monomer(hexafluorobutyl methacrylate),control the ratio of various raw materials,reaction time and temperature.Then,a fluorine-containing acrylic resin was obtained by free radical polymerization.After several experiments to get the most optimized synthesis process:50 parts of butyl alcohol,50 parts of butyl acetate,42 parts of methyl methacrylate(MMA),29 parts of butyl acrylate(BA),1.5 parts of acrylic acid(AA),24 parts of hydroxyethyl acrylate,Cyanide 1.5 parts,and 8 parts of hexafluorobutyl methacrylate,the reaction temperature was 85 ℃ and the reaction time was 4 h.2.The synthesized fluorine-containing acrylic resin was formulated with a certain ratio of the crosslinking agent(Cytec 325)、epoxy resin、diluent(n-butanol and ethylene glycol monobutyl ether)and the catalyst.The mass ratio of the various components is:M(resin):m(crosslinking agent):m(epoxy resin):m(diluent):m(catalyst)= 50:20:150:3:0.5.Coated with steel bar on the surface of stainless steel,curing temperature of 185 ℃,curing time of 10～15min.And ultimately get a transparent degree,anti-fouling performance,hardness and impact resistance,hardness,wear resistance,salt spray resistance in line with national standards of stainless steel coating.3.A modified leveling agent containing nano-silica(Si02)was added in the middle of the prepared coating.Through several tests the solid content of the paint about 15%,add about 1%of nano-silica(SiO2)would obtain better paint stability,it would make nano-silica(SiO2)particles in the paint stable for a long time(more than four weeks)and would not appear obvious particle settlement.The leveling performance of the stainless steel coating with steel roll is also improved.At the same time,different kinds of coatings on the coated titanium stainless steel surface,it was found that only the samples with nano-silica(SiO2)were added to the wear resistance and hardness to meet the requirements.The modification of polypropylene described in this paper is mainly through the surface modification of acicular wollastonite,then the modified wollastonite is mechanically blended with polypropylene,To obtain excellent mechanical properties of polypropylene/wollastonite composite materials.The main contents include the following aspects:1.Select the appropriate type of needle-like wollastonite,The optimum reaction conditions for wollastonite modification were determined by several tests:ethanol as the reaction solvent,stearic acid content of 0.5%,silane coupling agent KH-792 content of 1.5%,stirring speed of 1000r/min,the reaction temperature of 80 ℃,got the best effect of modification.The modification of modified wollastonite was carried out on the surface morphology and hydrophobicity test,It was found that the modified wollastonite could float completely on the water surface,and the oil absorption value could meet the requirements.The surface modification effect was obvious.2.The modified needle-like wollastonite was blended with polypropylene(PP)in different proportions.First in the micro-mixed rheometer extrusion granulation,After several tests,the appropriate blending granulation conditions were obtained:The reaction temperature is 180 ℃,the rotation speed is 100r/min,the double screw rotates in the same direction.The samples obtained by blending and granulation were injection molded and tested for mechanical properties,got excellent mechanical properties of composite materials,determine the best mass ratio of blending between 15%and 20%.On the basis of micro-experiments and the modified needle-like wollastonite with the current market of commercial polypropylene(PP)additives to do performance comparison,It can be determined that the modified acicular wollastonite can be comparable to the performance of some commercial acrylic(PP)inorganic fillers.