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Wen Gu changes epoxy resin system in
Epoxy resin is generally refer to two are contained in the element or oxygen of two above annulus base round high polymer compound, divide individual outside, their opposite element quality is not high. The molecular structure of epoxy resin is with lively annulus is being contained in molecular catenary oxygen radical group is a feature, annulus oxygen base the extreme that the group can be located in molecular catenary, medium occasional becomes cricoid structure. Because lively annulus is contained in molecular structure oxygen radical is round, make it can happen to cross-linking reacts and be formed with the solidify agent of a variety of types not dissolve not of frit have the 3 high polymer to reticulate structure. It is by annulus oxygen chloric propane and double phenolic A or multivariate phenolic, polybasic acid, multivariate amine, multivariate alcohol undertakes condensation polymerization reacts and make. A lot of active are contained in the molecular catenary as a result of epoxy resin base round, can fall in the action of all sorts of solidify agents, cross-linking solidify makes structure of meshy bodily form, make resin of hot solid sex. Not the epoxy resin of solidify is a kind thermoplastic colophony, differ because of what the element measures volume and exist with liquid state and solid state form. As a result of this kind of structure of epoxy resin, make have stick exceedingly goodly receive gender, corrosion resistance, hot property, mechanical function and inferior solidify shrinkage, epoxy resin applies extensively at advanced composite material. What require solidify temperature according to place is different, the solidify of epoxy resin can be divided for microtherm solidify (room temperature is the following) , cold curing (room temperature 50 ℃ ) , in lukewarm solidify (50 ~ 130 ℃ ) with high temperature solidify (130 ℃ above) . Solidify technology can reduce microtherm to basically be mixed by equipment of costly mould, high-energy bad news greatly the high cost that the place such as complementary makings brings high-powered technology, it is to reduce colophony radical a of cost of composite material component very important way. Although high temperature solidify can achieve the solidify result with the good performance such as hear resistance. But because solidify temperature is higher, the internal stress that makes product data generation larger, affect dimension precision control, serious when still can bring about material to be destroyed ahead of schedule. Then in lukewarm solidify asks commonly with respect to what suit people more. Opposite at high temperature solidify, as a result of in lukewarm solidify temperature is inferior, colophony system is operating the working life below temperature to shorten, go against shape craft. Because this is in solidify process, the solidify agent that often adds certain amount and accelerant in order to accelerate resinous solidify. On preparation and function, as a result of temperature moderate, preserved the performance with higher epoxy resin already, can managing cost, reduce solidify to shape internal stress of the resinous in the process, can satisfy the requirement of factory and consumer more. So, development goes those who differ is medium the direction of a pursuit that system of lukewarm solidify epoxy resin is people. Epoxy resin beforehand dip makingsBecause epoxy resin has exceedingly good craft sex, better hear resistance and good mechanical performance. It is the important colophony matrix in domain of advanced composite material all the time. Epoxy resin beforehand dip makings is fasten by system of epoxy resin, solidify and the compound put oneself in another's position that strengthen fiber composition, its quality stand or fall affects the quality of composite material component and performance directly, it is the intermediate base material of goods of preparation composite material, beforehand dip makings is had not only stick admirably receive performance, still have good tenacity and flexibility, and be in be not fiber to just shape to what go up solidify character is good. The structural part that can serve as advanced composite material is used, be moved to wait for the composite material goods of all sorts of utility at spaceflight industry and recreation by wide application. Heat up method of melt macerate preparationBeforehand the preparation method that dip expects has melt colophony way (hot melt dipping process) , pulverous dipping process, fiber mixes weave, CFRTP to shape law, colophony film law a variety of, among them what melt colophony law applies is most. Melt colophony law is resinite the department heats liquid, because viscosity of the resinous below melt condition is inferior, and have taller exterior pulling force, with enhance fibrous wellability very good, fasciculus passes the colophony on macerate of melt colophony chamfer, next via heating solidify is gotten beforehand dip makings. This method suits the imitate inside the lab quite beforehand dip expects shape, technical key is the design of melt colophony chamfer, want to maintain constant temperature of fluid of the colophony inside groove, and allow only already macerate resinous fasciculus is passed. Graph of its technological process is shown as follows:

Melt dipping process;burst;ulcerate;festers in dip solution is not used in the process, discharged a lot of inconvenience that the dissolvent in solution dipping process brings, reduced environmental pollution, saved stuff, improved product quality and manufacturing efficiency, beforehand mark of quality of dip makings resinous can gain accurate control, and exterior quality is better. The choice of colophony matrixChoosing appropriate colophony matrix is a decision beforehand the crucial place of dip makings quality. Epoxy resin beforehand the main demand that dip expects is: Summer does not stick a hand, do not send in the winter fragile. This stipulated matrix resinous softening point should satisfy: Summer is 36 ~ 37 ℃ , it is 30 ~ in the winter 32 ℃ . Prep above of colophony softening point when afore-mentioned temperature, beforehand dip makings allots in inferior temperature fragile; Under afore-mentioned temperature when, fall in higher temperature beforehand dip makings is tacky. Besides softening point, return the solidify temperature that should restrict epoxy resin matrix at the same time, general and optimal temperature is 120 ~ 130 ℃ , solidify time does not exceed 90 minutes. Can be adjusted through controlling matrix resinous viscosity beforehand dip expects stick receive performance, matrix colophony viscosity wants enough low, in order to make sure matrix can infiltrate adequately every monofilament in fasciculus, obtain fiber and matrix interface stronger stick receive a gender, but stick the retentivity that receives a gender to rise, make beforehand dip makings does not flow in process of keep in storage drip, want to raise resinous viscosity again. Accordingly matrix resinous viscosity should be satisfied both the balance requirement between. Use as epoxy resin beforehand the matrix colophony that dip expects is phenolic aldehyde mostly model with double phenolic A model, and contain at least average the annulus of two above oxygen radical is round, will tell onefold epoxy resin matrix to satisfy afore-mentioned requirements very hard commonly, normally the combination that uses a few kinds of different epoxy resins comes true. The choice of solidify agentNot the epoxy resin of solidify is agglutinant liquid or it is brittleness solid, without economic value, undertake with solidify agent solidify cross-linking generates ability of three-dimensional network structure to realize final utility only. Epoxy resin has a lot of kinds, but the sort that the sort of solidify agent exceeds epoxy resin far. Because epoxy resin is right the dependence of solidify agent is very big, selecting solidify agent according to utility so is very important. Sort of agent of epoxy resin solidify is various, the basis produces craft and applied characteristic, can divide commonly be in to show model with conceal model. Next watches are watch of classification of agent of epoxy resin solidify:

China unsaturated polyester resin (UPR)
Show in model basically pointing to the fission of epoxy resin double set that uses generally at present is, solidify agent and epoxy resin departure are deposited, when using, mix in proportion again, it is common use solidify agent; What conceal solidify agent points to is agent of this kind of solidify and epoxy resin after mixing, long-term stability falls in room temperature condition, and need to expose only begin reaction namely below requirement of hot, smooth, moisture. Agent of this kind of solidify basically is to use physics and chemical method to close of solidify agent active. Because conceal solidify agent can mix with epoxy resin,make liquid state compound, its apply limits to be packed from sheet gooey circle in the air seal the respect such as makings, farinaceous coating to develop to coating, impregnating varnish, fill. Conceal solidify agent is the key task of research and development. Solidify reaction attributes chemical response, the effect that suffers solidify temperature is very big, temperature heighten, react speed is accelerated, gel time shortens; Rise of gel time along with temperature to numerical value, show linear downtrend roughly. But solidify temperature often makes condensate function drops high too, put in the upper limit of solidify temperature so; Must choose the temperature that makes the function of solidify speed and condensate eclectic, will regard appropriate solidify as temperature. Press solidify temperature to be able to be solidify agent cent 4 kinds: ① falls in room temperature can the microtherm solidify agent of solidify; ② comes in room temperature the cold curing agent of 50 ℃ solidify; 50 ~ of ③ of 100 ℃ in lukewarm solidify agent; 100 ℃ of ④ the agent of high temperature solidify of above. Generally speaking, high temperature solidify can achieve the solidify result with the good performance such as hear resistance. But because solidify temperature is higher, the internal stress that makes product data generation larger, affect dimension precision control, serious when can bring about material to be destroyed ahead of schedule. Solidify temperature still can bring the range of auxiliary material select material such as goods core model, mould higher narrow, workmanship is complex with bad news can advanced problem, go against cost reduce. When other explicit product shapes, can contain sometimes not high temperature resistant inside accessory, this kind of circumstance does not allow solidify of high temperature of epoxy resin matrix. Because this people hopes epoxy resin can have inferior solidify temperature commonly, and in lukewarm solidify has solidify temperature low, lax to mould requirement, internal stress is little, the advantage such as dimension stability, because this has vast development space.

2024
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