| Crosslinking agent plays an important role in the finishing process of the fabric.The formaldehyde-containing crosslinking agent is harmful to the human body and environment because of containing formaldehyde,and most of the cross-linking agent needs to be in high temperature condition to make a good effect.The fiber will be damaged and the retention rate of the sample after finishing will be very low under the high-temperature condition.Therefore,it will be a trend of future research and development to study cross-linking agent which can fully react with fiber at low temperature to save energy and reduce fiber damage.In this study,two methods were used to synthesize epoxy crosslinking agent based on the reaction of epoxy chloride with propylene glycol 200,400,1000.The first is the sodium metal was used,sodium alcohol was made by the reaction ofsodium and polypropylene glycol,and then the reaction of sodium alcohol and epoxy chloride.This method is simple and easy to control,but the reaction time is longer.The second one is the synthesis of crosslinking agent by boron trifluoride etherification,that is the ring-opening reaction was happened between epichlorohydrin and polypropylene glycol,and thenthe closed-loop in the basic conditions.The reaction conditions of this method are mild,easy to control and simple to operate.The crosslinking agent was characterized by FTIR and NMR.The epoxy value and the yield of the product were used as the main evaluation indexes,and the fastness of brushing after coating was used as auxiliary index to evaluate the crosslinking performance.The optimal synthesis method and synthesis process were obtained by comparison,and the products obtained in the optimal process were applied to obtain the target of low temperature crosslinking.When the synthesis of epoxy crosslinking agent is through sodium metal and the raw material is polypropyleneglycol 400,the optimum reaction conditions were 1:3 of the molarratio of alcohol to alkane,50℃ of etherification reaction temperature,5h of alcohol-sodium reaction time,7h of etherification reaction time.When the raw material is polypropylene glycol 1000,the optimum reaction conditions were 1: 3 of the molarratio of alcohol to alkane,50℃ of etherification reaction temperature,4h of alcohol-sodium reaction time and 7h of etherification reaction time.And the product of polypropylene glycol 400 has light color,high yield,high epoxy value and dyeing fabric wash fastness.When the synthesis of epoxy crosslinking agent is through boron trifluoridediethyl ether catalysis,the main factors influencing the reaction were the ratio of alcohol to alkane,the reaction temperature of ring opening,the amount of catalyst used.The secondary factors were the reaction time of ring opening,the temperature of closed-loop reactionand the time of the closed-loop reaction.The optimum conditions were 1:4ratio of alcohol to alkene,50℃ of ring opening,0.2m L of catalyst,3h of ring-opening reaction time,50℃ of closed-loop reaction time and 4h of closed-loop reaction time.The results showed that the product of polypropylene glycol 400 was better than that of the other three products with different molecular weight.The IR and NMR results showed that the epoxy group was successfully grafted onto the polyether chain.By the comparison of the products synthesized by the twomethods,it showed that the epoxy value of the catalyst method was higher than that of the metal sodium method,and the epoxy value was higher than that of the metal sodium method.And the problem of long reaction time of sodium metal was solved.So boron trifluoride ether catalyst has a better effect of synthesis and application.The best effect was achieved when the curing temperature was 120℃ and the amount of crosslinking agent was 4g / L,and the goal of low temperature crosslinking was achieved. |
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