Study On Preparation And Modification Of One-component Silicone Encapsulent

Epoxy-modified hydromethylcyclosiloxane mixtures(EMHCM)is a kind of important derivative of hydromethylcyclosiloxane mixtures(HCM),and it is also an intermediate for the preparation of high-performance high-power white LED encapsulent.The structure and composition of EMHCM has a significant impact on the performance of the encapsulent.In this paper,EMHCM was prepared by using 4-vinylcyclohexane and HCM as the main raw materials and catalyzed by chloroplatinic acid-triphenylphosphine isopropanol.The structure of the product was characterized by FT-IR and ~1H-NMR.The structures and compositions of the reaction materials and products were analyzed by gas chromatography-mass spectrometry(GC-MS),and the cleavage mechanism of the main component of the mass spectrum was discussed.The results showed that the main components of the reaction materials were and the reaction products were mostly(-p1)by GC-MS.By comparing the cleavage mechanism of the mass spectrum,it is concluded that EMHCM is easy to form[M-111]~+excimer ion in the positive ion mode,and further cleaves and loses the free radicals such as methyl and hydrogen from the ring,to form the stable fragment ions.The composition and content of EMHCM is determined effectively by this method that is of great reference value for the production of silicone resin used as high performance LED encapsulent.Phenyltriethoxysilane,diphenyldimethoxysilane,hydromethylcyclo-siloxane,divinyl tetramethyl disiloxane as raw material,water solution condensation method were used to prepare a new one-component of LED encapsulation materials,the method effectively improve the silicone materials refractive index and mechanical properties.The structure and properties of the products were characterized by FT-IR,~1H-NMR,DSC and TG.The results showed that the silicone rubber was successfully synthesized.Experiment of silicone rubber of refractive index,hardness and resistance temperature performance testing,the results show that,encapsulation adhesive refraction rate is as high as more than 1.53,cured silicone rubber initial decomposition temperature is 310?,600?when samples weight loss is only less than20%,with excellent resistance to thermal properties.The experiment also found that can be adjusted by changing the dosage of benzene cured hardness,so as to realize the controllable elastic.Graphene is a new material to improve thermal conductivity and thermal conductivity.Graphene composite single-component silicone resin prepared by the LED packaging glue,the adhesive has a significant impact.In this paper,GNS and F-GNS were treated with graphene oxide,and the modified single-component silicone was obtained by ultrasonic curing.The structure of the product was characterized by FT-IR,the thermogravimetric analysis and Dynamic thermomechanical analysis(DMA)to analyze the properties of the product.The results show that GNS and F-GNS improve the thermal stability of the modified resin.The permeability of the modified resin is lower than what the transmittance of F-GNS has little effect on the resin.The GNS and F-GNS are improved by DMA analysis The modified mechanical properties of modified silicone resin,the modified products to improve the silicone silicone adhesive has an important role.Fluorine-containing materials have low surface properties and high thermal stability,while silicone materials require smaller surface adhesion and a certain fluorine content to reduce their surface adhesion.In this experiment,hydrogen-containing resin and hydrogen-containing double-head synthetic hydrogen-containing resin,and then with the acrylic acid trifluoroethyl ester and vinyl resin synthesis of fluorine-containing silicone resin.By means of FT-IR,contact angle,thermogravimetric and DMA test,the contact angle of fluorine-containing silicone resin was 95.2°,and the weight loss was increased from 35%to 22%.From the DMA,it was found that the increase of fluorine content was beneficial Improve the damping properties of materials.Adding a certain amount of fluorine to improve the thermal stability of LED encapsulated plastic,low surface and high damping performance has a great effect.