The Synthesis Of Aliphatic Glycidic Ester Epoxy Resin And Preparation Of Sizing Agent For Carbon Fiber

Sizing agent is an important assistant which necessary for the carbon fiberproduction process. It not only can protect the fiber surface, suppress theoccurrence of wool yarn and monofilament fracturing in deep process, but alsoimprove both the transfer efficiency and the interface performance of theinterface layer. Therefore, the quality of the sizing agent plays a crucial role inimproving the quality and performance of carbon fiber.This thesis provides a synthesis method of epoxy resin which suitable as acarbon fiber composite material, diglycidyl endomethylenetetrahydrophthalate(NAG). Meanwhile, it has selected and prepared suitable emulsifiers, nadic aciddi-(3-polyethylene glycol group)-glycidyl (A2) and nadic acid polyethyleneglycol monoester (A4). Also the paper has used homemade emulsifiers toemulsify homemade epoxy resin, and prepared to meet the requirements ofemulsion sizing agent for carbon fiber.This thesis worked out the synthesis process of NAG, and started from thesynthesis of raw material, endomethylenetetrahydrophthalic anhydride (NA),which used to synthesize NAG. NA was synthesized by cyclopentadiene andcis-butenedioic anhydride. And the optimal conditions in the synthesis reaction ofNAG were as follows: the ratio of NA to epichlorohydrin and distilled water inmole was1:3:2, the catalyst was tetrabutyl ammonium bromide, and the amountof the catalyst was2%. The ring-opening reaction occured at a temperature of110℃. The reaction time was2hours. Then, when the temperature of the reactionsystem was lowered to room temperature, dichloromethane was added to thesystem as the cyclization reaction solvent. Added NaOH solution to the system under a temperature of50℃. The mass fraction of NaOH solution was30%, theratio of NaOH to NA in mole was3:1. Cyclization time was1hour. The resultsshowed that epoxide number was0.56~0.60, and the yield can reach90%.Curing conditions were as follows: chose MDA as a curing agent. MDA wasadded to the cure system at a mass ratio as NAG:MDA=3.5:1. The reaction wascarried out at120℃for2hours.This paper has designed and synthesized four emulsifiers. They were nadicacid di-(3-polyethylene glycol group)-glycidyl A1, A2, and nadic acidpolyethylene glycol monoester A3, A4. Among them, the composite emulsifiermixed by A2and A4can be good matched with NAG. The stability of theemulsion was up to20days.By doing large numbers of experiments, the optimum conditions forpreparation of sizing agent were as follows: the emulsifier formulation wascomposite of A2and A4according to weight ratio of2:8, the weight of theemulsifier was from10%to20%by weight of epoxy resin, the emulsificationtemperature was from40℃to50℃, curing agent was MDA, the amount ofcuring agent was a weight ratio of NAG:MDA=3.5:1.The performance test results of the emulsion show that storage stability ofthe emulsion is one month, dilution stability of the emulsion is good. The particlesize analysis result of emulsion shows that the average particle size of theemulsion is0.966μm, distribution of particle size is uniform, particle size is thesize within the requirements of the emulsion stability. The membrane has beenfully cured, well-distributed, transparent, and shiny, which confirms the role andeffectiveness of the sizing agent prepared by this topic has reached the expecteddemand.