Application Research On UV-curing Of Liquid Rubber

Due to its high efficiency,environmental protection and economic advantages,light curing technology has been widely studied in the research field.Traditional light curing technology mostly uses acrylates,unsaturated polyesters,epoxy resins,etc.as prepolymers,which have a fast curing rate and good product performance.Liquid rubber is also used in the field of light curing due to its good processing properties,and easy adjustment of its physical and chemical properties.Although the application of light-curing technology to liquid rubber has always been a research hotspot,its research fields are mostly focused on liquid rubber with active functional groups on the molecular chain,while liquid rubber without active functional groups is rarely involved.The thiol-ene click chemistry is receiving increasing attention due to its simple and efficient reaction,and good selectivity.In this topic,the UV curing of liquid rubber with and without active functional groups was studied systematically.It was innovatively proposed that polybutadiene liquid rubber and ethylene propylene diene rubber(EPDM)were mixed with mercaptan without grafting active functional groups,and cured under light by thiol-ene reaction mechanism.The results show that EPDM can react well with mercaptan to obtain cured rubber,and the cured rubber has a stable cross-linking network and good combination properties.In this topic,the hydroxyl-terminated polybutadiene liquid rubber was functionalized with acryloyl chloride to graft acrylate groups,and the grafted acrylate-terminated polybutadiene was combined with acrylates.The reactive diluent is mixed for light curing,and its performance as a light curing adhesive is explored.Studies have shown that the functionalized modification efficiency of hydroxy-terminated polybutadiene by acryloyl chloride is very high,with a blocking rate of 94.2%.When the mass fraction of the prepolymer is 40%and the initiators used are photoinitiators 1173 and 184,the bonding strength and tensile strength of the product reach the best,and the heat resistance is good.The system has a moderate viscosity and is easy to potting.In this project,polybutadiene and EPDM liquid rubber were used in mercaptan ene reaction for UV curing,and the application of EPDM in acrylate system was also studied.The results show that EPDM can be cured well under the reaction mechanism of mercaptan olefin,and the rubber with good properties can be obtained.Adding a small amount of trimethylolpropane triacrylate is helpful to the formation and perfection of crosslinking network.When the double bond concentration of sulfhydryl group and system is 3:1,adding 1%trimethylolpropane triacrylate,EPDM rubber with complete curing,uniform morphology,stable crosslinking network and good properties can be obtained.