Synthesis And Application Of Pentaerythritol Tetrakis (3-Mercaptopropionate)

The click reaction of thiol has the advantages of high efficiency and no by-products.Polymercapto carboxylate has become a widely used thiol due to its low odor,simple synthesis and low volatility.As a kind of polymercaptocarboxylic acid ester,pentaerythritol tetrakis(3-mercaptopropionate),in the traditional synthesis process,a water-carrying agent needs to be added during the reaction,and tedious post-processing such as water-carrying agent,alkaline washing,and water washing.This article optimizes the synthesis process conditions of pentaerythritol tetrakis(3-mercaptopropionate),and studies the application of PETMP in materials.The research content and results are as follows:1.PETMP is synthesized with p-toluenesulfonic acid as a catalyst and mercaptopropionic acid and pentaerythritol as raw materials.Within the scope of the experiment,the best synthesis process conditions:reaction temperature 90 ℃,n(pentaerythritol):n(mercaptopropionic acid)molar ratio 1:5,reaction time 6 h,catalyst dosage(w/w based on alcohol)4.5%.The yield is 90%.Through 1H-NIR analysis,the methylol esterification rate of pentaerythritol is 94.8%.Compared with PETMP from different manufacturers on the market and different synthesis processes in the literature,a higher purity PETMP has been synthesized.It adopts the vacuum method,the process is simple,and it is green and environmentally friendly.2.By introducing the third component epoxy resin(E51)into the PETMP-Trimethylolpropane triacrylate(TMPTA)system to form an interpenetrating network polymer of PETMP-TMPTA-E51,the defect of poor mechanical properties of the PETMP-TMPTA system is changed.Considering,when the molar ratio of the epoxy group of the epoxy resin to the sulfhydryl group of the thiol in the system is 0.7,the performance of the PETMP-TMPTA-E51 interpenetrating network polymer formed is the best.The different interpenetrating polymer networks formed by 2,3-Bis((2-mercaptoethyl)thio)-1-propanethiol(GST),trimethylopropane tris(3-mercaptopropionate)(TMPMP)and pentaerythritol tetrakis(3-mercaptopropionate)(PETMP)were compared.The results show that compared with TMPMP system and GST system,the impact strength of the interpenetrating network polymer formed by PETMP system is 96.0 kJ/m2,and the bending strength is 118.9 MPa,showing excellent toughness.It can be applied to the field of thermosetting elastomer3.Using PETMP,GST and Bis(isocyanatomethyl)benzene(XDI),1,6-Hexamethylene diisocyanate(HDI),isophorone diisocyanate(IPDI)were compounded to prepare a medium-high refractive index polythiourethane optical resin material.The refractive index of the material is about 1.62,the light transmittance in the visible light region is above 94%,and the light transmittance is excellent.The UV cut-off absorption wavelength of the material is about 310 nm,and the absorption capacity of UV light is better.It can be applied in many fields such as optical lenses.