Preparation Of Cochineal/P（MMA-DMC）/SiO₂ Composite Microspheres And Study On Dyeing On Cotton Fabric

As a new type of composite material,color composite microspheres have different physical and chemical properties due to different combination methods and compositions.In this paper,polymethyl methacrylate/methylacryloxyethyl trimethyl ammonium chloride（DMC）/N-methylol acrylamide（NAM）composite microspheres（PMNAD）were prepared by soap-free emulsion polymerization with methyl methacrylate（MMA）as the main monomer.Using cochineal as natural dye model,cochineal composite microspheres（CO@PMNAD）were obtained after blending and adsorption with PMMA microspheres,which were applied to dyeing cotton fabrics.Polymethyl methacrylate/DMC/Si O₂（PMDS）composite microspheres were prepared by introducing modified nano silica to further improve the light stability and staining rate of cochineal.The main research contents are as follows:（1）The particle size distribution（PDI）and average particle size of PMNAD microspheres prepared by soap-free emulsion polymerization were 0.028 and 225.4 nm.After dyeing with cochineal,the PDI of dye microspheres was 0.052,and the average particle size was 244.8 nm.The potential before and after staining changed from+44.8 m V to+36.7m V.Infrared analysis showed that PMNAD microspheres were successfully prepared,and thermogravimetric analysis showed that PMNAD microspheres had good thermal stability.The optimal dyeing process:dye concentration of 200 mg·L^-1,a temperature of 50℃,time of 10 min,and mixing rate of 200 rpm.Compared with direct dyeing of cochineal,the cotton fabric dyed by color microspheres has improved the soap-washing fastness and wet and dry rubbing fastness by 2 to 3 degrees,and the sun fastness by 1 degree.（2）Nano-Si O₂ particles were prepared by sol-gel reaction and then modified by KH570to prepare modified nano-Si O₂.Pickering emulsion polymerization prepared PMDS composite microspheres.Optimal synthesis process:MMA 10 g,modified Si O₂ 0.2 g,DMC/MMA 10%,AIBA/（MMA+DMC+Si O₂）1%,DMDDAC/DMC 2%,the prepared PMDS composite microspheres have uniform particle size and more uniform distribution,with an average particle size of 221.7 nm.Potential+65.4 m V;Infrared analysis shows that modified nano-Si O₂ and MMA were successfully polymerized together.The optimal adsorption process was as follows:the dye concentration was 0.7 g·L^-1,the time was 20 min;the temperature was 60℃,the average particle size of CO@PMDS microspheres was 245.6nm,the potential was+37.8 m V.（3）CO@PMDS Composite microsphere dyed pure cotton fabric,best dyeing process:CO@PMDS composite microspheres 100 mg,dyeing temperature 60℃,dyeing time 30 min,compared with direct dyeing of cochineal,CO@PMDS composite microspheres dyed pure cotton fabric,soap washing fastness,dry and wet rubbing fastness are improved by 2 to 3levels,sun fastness is increased by 2 levels.Compared with the mordant dying method,the dyeing rate of the pure cotton fabric dyed by CO@PMDS composite microsphere has been greatly improved.