| Polyacrylate has many specific properties, such as good film-forming and cohesiveness,good heat resistance and antioxidant, and they have been widely used as pigment printingadhesive. But they had the following defects: poor water resistance and high hardness of thefilm, cool brettle-hot sticky performance of the film, and the most serious problem that thehandle and colour fastness of the printed fabric was difficult to reconcile, these defects affectedthe quality of the pigment printing products to a large degree. Polysiloxane has attracted muchattention due to the excellent properties such as low surface tension and glass transitiontemperature, high flexibility and hydrophobicity, the research found that it was an effectivemethod to improve the polyacrylate adhesive by the copolymerization reaction of acrylatemonomers with organo silicon monomers with vinyl functional groups, but it was a researchdifficulties to got a suitable organo silicon monomers with vinyl functional groups for manyyears. Therefore, a new organo silicon monomer that double-terminated acrylamide-propylpolysiloxane (diAAp-PDMS) was synthesized and used to modify polyacrylate latex, then thelatex was used for pigment printing, the printing fabric had good fastness and softer handlemeanwhile. The following was the specific research contents and results:Part1: The choice of synthesis methods of double terminated acryloyl-group polysiloxanemodified monomers.In this part, a double-terminated acrylamide-propyl polysiloxane (diAAp-PDMS) or adouble-terminated acryloyloxy-propyl polysiloxane (diAOp-PDMS) were synthesized viaacylation reaction by acryloyl chloride and double terminated amino-propyl polysiloxane ordouble terminated hydroxy-propyl polysiloxane respectively, and applied in preparing modifiedpolyacrylate miniemulsion. Influence of synthetic factors on the synthetic yield were researchedrespectively, the synthesis conditions was optimized, the synthetic characteristics and theproperties of two kinds of silicon-modified polyacrylate latex film and their pigment printingwere measured and compared with each other. The results showed that the reactivity of doubleterminated amino-propyl polysiloxane was higher than that of double terminated hydroxy-propyl polysiloxane obviously when being reacted with acryloyl chloride. Compared with thediAOp-PDMS, the synthetic yield of diAAp-PDMS was higher, the hydrophobicity ofpolyacrylate film modified with diAAp-PDMS was higher; the breaking tenacity of filmmodified with diAAp-PDMS was lower and its breaking extension was bigger, the work of breakof the film modified with diAAp-PDMS was bigger. The colorfastness to crocking (dry and wet)of the diAAp-PDMS modified polyacrylate latex pigment printed fabric was higher than that ofthe diAOp-PDMS modified latex pigment printed fabric about half a level, and its handle wasmore softer. The studies showed that it was a better way to synthesis double terminatedacryloyl-group polysiloxane that diAAp-PDMS was synthesized via acylation reaction byacryloyl chloride and double terminated amino-propyl polysiloxane.Part2: Study on preparation and properties of polyacrylate miniemulsion modified withdiAAp-PDMS.In this part, an silicone-modified polyacrylate latex was prepared by double terminatedacrylamide-propyl polysiloxane (diAAp-PDMS) as organo silicon modifier and acrylatemonomers. The influence of the synthesis factors of diAAp-PDMS modified polyacrylate suchas that the emulsion polymerization methods, emulsification system, the molecular weight anddosage of diAAp-PDMS on these properties of the modified miniemulsion, the properties of themodified film and the properties of pigment printing were studied. The structure and propertieswere analyzed by FTIR, DLS, TG and DSC. The result showed that the emulsionpolymerization exhibited good polymerization stability of miniemulsion polymerization. Whenthe mass ratio of anionic emulsifier to nonionic emulsifier was1:1and the dosage of compoundemulsifier was6%, the emulsion polymerization exhibited good polymerization stability, theproperty indicators of the latex showed all well. With the increase of the molecular weight ofdiAAp-PDMS, the degree of crosslinking of the modified film decreased, the amount ofaggregated PDMS on the surface of film increased, the hydrophobicity of the film decreased,the mechanical properties of the film became worse, the colour fastness to rubbing and thesoftness of the pigment printed fabric became worse. The dosage of diAAp-PDMS with1700molecular weight was8%, the stability of modified latex was good, the degree of crosslinkingof the film was the highest, the hydrophobicity of the film was the strongest, the mechanicalproperties of the film was the best, and the properties of the pigment printed fabric was good. The FTIR analysis indicated that the diAAp-PDMS was crosslinked with polyacrylate. TheDLS analysis showed that the average diameter of modified emulsion was86nm anddistribution was narrow. The DSC and TG analysis indicated that the glass transitiontemperature of the diAAp-PDMS modified polyacrylate polymer decreased, the thermaldecomposition temperature of the polymer increased and the thermal stability of the polymerincreased.Part3: Study on application of diAAp-PDMS modified polyacrylate pigment printingadhesive.In this part, the diAAp-PDMS modified polyacrylate adhesive was used for pigmentprinting on cotton fabrics. The dosage of adhesive, curing temperature and curing time on thethe colour fastness to rubbing, the softness and the K/S were studied, and compared with otherpigment printing adhesive. The result showed that when the dosage of adhesive was15%, thecuring temperature was160℃, the curing time was3min, the colour fastness to dry and wetrubbing of the printed fabric could reach grade4-5, and its handle was softer. Compared withother pigment printing adhesive on the colour fastness to rubbing, the softness and the K/S ofprinted fabric, the properties of diAAp-PDMS modified polyacrylate adhesive was better.The results of project showed that the diAAp-PDMS modified polyacrylate adhesive latexprepared by miniemulsion polymerization can be used as pigment printing, the colour fastnessto dry and wet rubbing of the printed fabric could reach grade4-5, and its handle was softer,basically achieved the objective unification of handle and fastness. |
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