Due to the rigid Si-O-Si backbone,silicone rubber(SR)have a widespread application in extreme environment such as high temperature and high-level radiation.However,the radiation stability of SR still does not meet the...Due to the rigid Si-O-Si backbone,silicone rubber(SR)have a widespread application in extreme environment such as high temperature and high-level radiation.However,the radiation stability of SR still does not meet the practical needs in special radiation environments.Herein we prepared epoxy POSS(e POSS)/SR nanocomposites with excellent thermal stability and radiation resistance.As a physical crosslinking point in the SR,addition of small amount of ePOSS not only enhanced the mechanical properties of the matrix,but also improved its thermal stability greatly due to their good compatibility.e POSS/SR had higher radiation stability in air than SR owing to the inhibition of radiation oxidation by ePOSS,and the yield of main gaseous radiolysis products(CH_(4),H_(2),CO and CO_(2))of SR and ePOSS/SR nanocomposites was determined.By analyzing the changes of chemical structure,thermal properties and mechanical properties of the ePOSS/SR nanocomposite,combined with the characteristics of gas products afterγ-irradiation,the radiation induced crosslinking and degradation mechanism of the nanocomposites was proposed comprehensively.展开更多
Fabricating a high-performing thermoset using bio-based flame retardant is critical for the sustain-able development of engineering materials with superior fire safety and robust mechanical properties.Herein,the epoxy...Fabricating a high-performing thermoset using bio-based flame retardant is critical for the sustain-able development of engineering materials with superior fire safety and robust mechanical properties.Herein,the epoxy(EP)composites with the industrial requirements are manufactured with a novel high-efficient,lignin-based flame retardant named DAL-x,which is fabricated by grafting 9,10-dihydro-9-oxa-10-phosphaze-10-oxide(DOPO)onto lignin.The resulting DAL-x/EP composite exhibits excellent flame retardancy with a desirable UL-94 V-0 rating and a satisfactory limiting oxygen index(LOI)of 29.8%due to the appropriate phosphorus content of DAL-x with adjustable molecular chain structure.More-over,the DAL-x/EP composite shows an unexpected improvement in the elastic modulus(∼36%)and well-preserved strength and ductility compared with those of pure EP.This work offers a feasible strat-egy for creating efficient bio-based flame retardants utilizing industrial waste lignin and preparing high-performance EP composites that meet the demanding requirement of fire retardancy in industries,con-tributing to the circular economy and sustainability.展开更多
基金financially supported by the Science Challenge Project(No.TZ2018004)the National Natural Science Foundation of China(NSFC,Nos.11575009 and 12075010)。
文摘Due to the rigid Si-O-Si backbone,silicone rubber(SR)have a widespread application in extreme environment such as high temperature and high-level radiation.However,the radiation stability of SR still does not meet the practical needs in special radiation environments.Herein we prepared epoxy POSS(e POSS)/SR nanocomposites with excellent thermal stability and radiation resistance.As a physical crosslinking point in the SR,addition of small amount of ePOSS not only enhanced the mechanical properties of the matrix,but also improved its thermal stability greatly due to their good compatibility.e POSS/SR had higher radiation stability in air than SR owing to the inhibition of radiation oxidation by ePOSS,and the yield of main gaseous radiolysis products(CH_(4),H_(2),CO and CO_(2))of SR and ePOSS/SR nanocomposites was determined.By analyzing the changes of chemical structure,thermal properties and mechanical properties of the ePOSS/SR nanocomposite,combined with the characteristics of gas products afterγ-irradiation,the radiation induced crosslinking and degradation mechanism of the nanocomposites was proposed comprehensively.
基金financially supported by the National Natural Science Foundation of China(Nos.51873196 and 51903222)the Australian Research Council(Nos.LP220100278,DP190102992 and FT190100188)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LY21E030001)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2022C03128).
文摘Fabricating a high-performing thermoset using bio-based flame retardant is critical for the sustain-able development of engineering materials with superior fire safety and robust mechanical properties.Herein,the epoxy(EP)composites with the industrial requirements are manufactured with a novel high-efficient,lignin-based flame retardant named DAL-x,which is fabricated by grafting 9,10-dihydro-9-oxa-10-phosphaze-10-oxide(DOPO)onto lignin.The resulting DAL-x/EP composite exhibits excellent flame retardancy with a desirable UL-94 V-0 rating and a satisfactory limiting oxygen index(LOI)of 29.8%due to the appropriate phosphorus content of DAL-x with adjustable molecular chain structure.More-over,the DAL-x/EP composite shows an unexpected improvement in the elastic modulus(∼36%)and well-preserved strength and ductility compared with those of pure EP.This work offers a feasible strat-egy for creating efficient bio-based flame retardants utilizing industrial waste lignin and preparing high-performance EP composites that meet the demanding requirement of fire retardancy in industries,con-tributing to the circular economy and sustainability.
