| At the earliest, N-hydroxymethyl acrylamide was used by The pigment printingas cross-linking agen in the Textile industry. Due to the cross-linking agent’s rubbingfastness and washing fastness resistance is lower, There will be released with a freeformaldehyde in the finishing and wearing. So Polyurethane will be cross-linkingagent instead of N-hydroxyl methyl, which can overcome the problem of freeformaldehyde of N-hydroxymethyl acrylamide. At the same time, It can improve therubbing fastness and washing fastness of pigment printing. Water-borne polyurethaneis widely favored by most of the manufacturers as a reactive water-bornepolyurethane. although the polyurethane cause less harm to humans and theenvironment, but its stability is poorer.In this paper, Isophorone diisocyanate (IPDI) and polyether polyols (N-310) arethe main materials. isopropyl alcohol is the solvent. The sodium bisulfite (NaHSO3)of low deblocking temperature is the blocking agent. The synthesis of the crosslinkerof blocked water-borne polyurethane is made from the self-emulsification method. Itcan effectively improve the rubbing fastness and washing fastness of pigment printing.At the same time, The storage stability will increase, The cost will low, And thesynthesis process will simple. This paper mainly discusses the content of thefollowing three aspects:(1) The study of the synthesis and properties of blockedwater-borne polyurethane;(2) The study of the synthesis and properties of modifiedwater-borne polyurethane with organic silane coupling agent;(3) the discussion of theapplication and process of blocked and modified water-borne polyurethane.The first part of this paper, It is mainly discusses and optimizes the effect factorsof the pre-polymerizing, blocking and emulsifying reaction. Finally it is concludedthat the best process is: with isocyanate (IPDI), polyether (Mn=1000) ternary alcoholas main materials, R(n (NCO)/n (OH)) was2.5, the pre-polymerizing temperature was70℃. the pre-polymerizing time was150minutes. was pre-polymers; With isopropylalcohol as solvent, sodium bisulfate (concentration was30%, n (NaHSO3)/n (NCO)was2) as the blocking agent. the blocking temperature was0~5℃and the time was40min. According to the solid content was30%, adding an appropriate amount of distilled water make pre-polymers emulsification dispersion with strong stirring.emulsification time was60min. Finally it will be obtained a stable water-bornepolyurethane.The second part of this paper, It is mainly discusses and optimizes the various effectfactors of the modification, blocking, emulsification reaction. Finally it is concludedthat the best process modification is: pre-polymers was modified by silane couplingagent KH–550(dosage was8%). the modification temperature was45℃and thetime was60min; Finally modified water-borne polyurethane emulsion was obtainedby blocking and emulsying.The third part of this paper, It is mainly discusses and optimizes the variouseffect factors of pigment printing process, anti-wrinkle finishing process and theanti-pilling finishing process. which blocked waterborne polyurethane was used forthe pigment printing crosslinker, can improve the dry rubbing fastness of cotton fabricfrom3to5, and improve wet rubbing fastness from2~3to4~5; Modifiedwaterborne polyurethane applied to anti-wrinkle and anti-pilling of cotton fabric,which can improve the elastic recovery Angle of cotton fabric from89.25°to209.78°, improve delayed elastic recovery Angle from102.81°to218.97°; It isimprove anti-pilling level of Pure cotton knitted fabric from2~3to4. polyether andpolyester type liquid applied to anti-wrinkle and anti-pilling of pure cotton fabric,which can improve the elastic recovery Angle of cotton fabric from89.25°to218.91°,improve delayed elastic recovery Angle from102.81°to225.17°; It is improveanti-pilling level of Pure cotton knitted fabric from2~3to4.At the same time, It isconcluded that the finishing effect will be no far by comparing modified polyurethanewith blended polyurethane of polyether and polyester.It is showed that the products are the blocked water-borne polyurethane andmodified water-borne polyurethane with organic silane by infrared spectroscopy(FTIR) analyzer; The DSC analyzer indicated that the deblocking temperature ofblocked water-borne is60~160℃. We will be clearly seen continuous film wasformed on the surface of fabric by scanning electron microscope (SEM), To sum up,this experiment in the products of waterborne polyurethane of synthesis is anexcellent finishing agent of formaldehyde-free. It has widly application prospect. |
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