Synthesis And Application Of Waterborne Polyurethane Associative Thickener

Thickener is an important auxiliary in the textile printing.At present,the most commonly used synthetic thickener in the market is polyacrylic acid thickener,which has high thickening ability but poor salt-resistance.The conventional polyurethane associative thickener has good salt-resistance but poor thickening ability.Based on this,two kinds of waterborne polyurethane associative thickener were studied,one was combing waterborne polyurethane associative thickener,another was branched waterborne polyurethane associative thickener,and they were respectively applied in fabric printing.The research contents and results were as follows:(1)A kind of combing waterborne polyurethane associative thickener with hydrophobic chain segment was synthesized using polyethylene glycol(PEG),isophorone diisocyanate(IPDI),octadecylamine polyoxyethylene ether and long-carbon alkyl alcohol as raw materials.The structure of the synthesized product was characterized by infrared spectroscopy(FTIR).The optimized synthesis process of combing waterborne polyurethane associative thickener was as follows:The molecular weight of PEG was 6000,the R value(molar ratio of NCO to OH)was 2.0,myristyl alcohol was selected,myristyl alcohol was 6%of the total mass of the reactant.The first step reaction was prepolymerization,the reaction temperature was 65? and the reaction time was 2 h.The second step reaction was chain extension reaction,the reaction temperature was 75 ? and the reaction time was 1.5 h.The third step was the end-chain reaction,the reaction temperature was 75? and the reaction time was 1.5 h.The combing waterborne polyurethane associative thickener was prepared under optimized synthesis process.The thickener was applied to the pigment printing of polyester-cotton fabric.The combing waterborne polyurethane associative thickener was prepared into an aqueous solution with a mass fraction of 3%.When the stirring speed was 6 r/min,the viscosity of the thickener was 7550 mPa·s.When NaCl accounted for 0.5%of the total mass of the thickener aqueous solution,the viscosity retention was 92.88%.Water retention of the thickener solution with a mass fraction of 3%was 0.3 cm/15 min.PVI value of the thickener was 0.26.Fabric color quantity(positive K/S value)was 17.42 after used for pigment printing.Color uneven degree was 0.27.The penetration rate were 82.10%.The removal rate of paste were 78.69%.The dry rubbing fastness of the printed fabric was 4-5 and the wet rubbing fastness of the printed fabric was 4?5.The comprehensive properties were fine.(2)A kind of branched waterborne polyurethane associative thickener was synthesized using polyethylene glycol(PEG),isophorone diisocyanate(IPDI),tetramethylene glycol,hyperbranched polymers Boltorn H20 and long-carbon alkyl alcohol as raw materials.The structure of the synthesized product was characterized by infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).The optimized synthesis process of branched waterborne polyurethane associative thickener was as follows:The R value(molar ratio of NCO to OH)was 1.8,tetramethylene glycol was 6%of the total mass of the reactant,hyperbranched polymers Boltorn H20 was 16%of the total mass of the reactant and lauryl alcohol was selected.The branched waterborne polyurethane associative thickener was prepared under optimized synthesis process.The thickener was applied to the reactive dye printing of cotton fabric.The branched waterborne polyurethane associative thickener was prepared into an aqueous solution with a mass fraction of 3%.When the stirring speed was 6 r/min,the viscosity of thickener was 11658 mPa·s,when NaCl accounted for 0.5%of the total mass of the thickener aqueous solution,the viscosity retention was 93.12%.Water retention of the thickener solution with a mass fraction of 3%was 0.3 cm/15 min.PVI value was 0.24.Fabric color quantity(positive K/S value)was above 18.95 after used for reactive dye printing.Color uneven degree was below 0.19,the penetration rate were above 75.91%and the removal rate of paste were above 85.65%.The dry rubbing fastness of the printed fabric was 4?5 and the wet rubbing fastness of the printed fabric was 4?5.The comprehensive properties were fine.