Investigation Of Thermo-responsive Microgels With Linear Transition Behaviors And Their Applications In Textiles

To the textiles used in daily lives,wearing comfort is crucial.Thus the comfort control of textiles attracts more and more interests in the last decades.In recent years,thermo-responsive polymers have been applied in traditional textiles to prepare smart textiles,such as intelligent wound dressing,smart breathable textiles and intelligent diving suit due to their thermo-responsive property.In this paper,various thermo-responsive microgels with linear transition behaviors were prepared.The transition behaviors of the microgels,such as particle size and linear response as a function of temperature were systematically studied.In addition,the microgels were cross-linked onto the cotton fabrics to prepare smart textiles.The comfort control and wearability of smart textiles were explored.The results obtained were as follows:N-isopropylacrylamide?NIPAM?,poly?ethylene glycol?methyl ether methacrylate(OEGMA₃₀₀)and poly?ethylene glycol?methacrylate?EGMA?were used as monomers,sodium dodecyl sulfate?SDS?was used as surfactant,N,N methylene bis acrylamide?MBA?was used as cross-linking agent,ammonium persulfate?APS?was used as initiator,and P(NIPAM-co-OEGMA₃₀₀-co-EGMA))was prepared by free radical emulsion polymerization.Afterwards the microgel emulsion was used as finishing liquid,1,2,3,4 butane tetracarboxylic acid?BTCA?as crosslinker and sodium hypophosphite?SHP?as initiator,the microgel was finished onto a cotton fabric by dipping-pre-baking-baking method.The experimental results showed that the transmittance of P(NIPAM-co-OEGMA₃₀₀-co-EGMA)microgel emulsion decreased with the increase of NIAPM amount.The particle size and de-swelling ratio of microgels and hydrophilic increased with the amount of NIAPM.The moisture permeability of cotton fabrics was enhanced with the temperature and weight gain ratio.Simultaneously the whiteness and softness of fabrics dropped with the weight gain ratio.The stiffness and breaking strength of fabrics also presented an increase with the weight gain ratio.P(MEO₂MA-co-OEGMA₃₀₀-co-EGMA)microgels were obtained by replacing NIPAM monomer with 2-methyl-2-acrylic acid-2-?2-methoxyethoxy?ethyl ester?MEO₂MA?monomer.The smart textile was prepared by using the microgel emulsion as a finishing liquid.Compared with P(NIAPM-co-OEGMA₃₀₀-co-EGMA),P(MEO₂MA-co-OEGMA₃₀₀-co-EGMA)possessed a weaker temperature response between 20 ^oC and 40°C.But the particle size distribution of the microgel was narrower,and its hydrophilicity was improved.The prepared smart textile had comfort control and antibacterial adhesion capabilities in a broad temperature range?24-37 ^oC?.Compared with P(NIAPM-co-OEGMA₃₀₀-co-EGMA)cross-linked cotton fabric,the softness of P(MEO₂MA-co-OEGMA₃₀₀-co-EGMA)cross-linked cotton fabric was significantly improved,but the whiteness was dropped significantly..When EGMA monomer was replaced with acrylic acid?AAc?monomer,P(MEO₂MA-co-OEGMA₃₀₀-co-AAc)microgels were obtained.Then the microgel emulsion was used to prepare a smart textile.The results showed that the amount of AAc did not influence on the linear transition of P(MEO₂MA-co-OEGMA₃₀₀-co-AAc)microgelsizeuponheating.Comparedwiththe P(MEO₂MA-co-OEGMA₃₀₀-co-EGMA)microgel,the particle size distribution of the P(MEO₂MA-co-OEGMA₃₀₀-co-AAc)microgel was significantly narrower.The change of moisture permeability in cotton fabrics cross-linked with P(MEO₂MA-co-OEGMA₃₀₀-co-AAc)microgels was much less than that in cotton fabrics cross-linked with P(MEO₂MA-co-OEGMA₃₀₀-co-EGMA)microgels.However,the fastness of the cross-linked microgels has been prominently improved.