A novel method was developed to enhance the utilization rate of steel slag(SS).Through treatment of SS with phosphoric acid and aminopropyl triethoxysilane(KH550),we obtained modified SS(MSS),which was used to prepare...A novel method was developed to enhance the utilization rate of steel slag(SS).Through treatment of SS with phosphoric acid and aminopropyl triethoxysilane(KH550),we obtained modified SS(MSS),which was used to prepare MSS/wood-plastic composites(MSS/WPCs)by replacing talcum powder(TP).The composites were fabricated through melting blending and hot pressing.Their mechanical and combustion properties,which comprise heat release,smoke release,and thermal stability,were systematically investigated.MSS can improve the mechanical strength of the composites through grafting reactions between wood powder and thermoplastics.Notably,MSS/WPC#50(16wt%MSS)with an MSS-to-TP mass ratio of 1:1 exhibited optimal comprehensive performance.Compared with those of WPC#0 without MSS,the tensile,flexural,and impact strengths of MSS/WPC#50 were increased by 18.5%,12.8%,and 18.0%,respectively.Moreover,the MSS/WPC#50 sample achieved the highest limited oxygen index of 22.5%,the highest vertical burning rating at the V-1 level,and the lowest horizontal burning rate at 44.2 mm/min.The formation of a dense and stable char layer led to improved thermal stability and a considerable reduction in heat and smoke releases of MSS/WPC#50.However,the partial replacement of TP with MSS slightly compromised the mechanical and flame-retardant properties,possibly due to the weak grafting caused by SS powder agglomeration.These findings suggest the suitability of MSS/WPCs for high-value-added applications as decorative panels indoors or outdoors.展开更多
Traditional flame-retardant plastics are technically difficult to chemically recycle.The development of newtypes of flame-retardant plastics that are intrinsically capable of being closed-loop recycled and are suffici...Traditional flame-retardant plastics are technically difficult to chemically recycle.The development of newtypes of flame-retardant plastics that are intrinsically capable of being closed-loop recycled and are sufficiently robust and stable to satisfy their practical application is urgently needed.In this study,closed-loop recyclable flame-retardant plastics with high mechanical strength and excellent chemical resistance are fabricated by cross-linking amino-terminated polyimide(PI-NH_(2))and aldehyde-terminated cyclophosphazene(CP-CHO)with imine bonds.The resultant flame-retardant plastic,which is denoted as PI-CP,exhibits a tensile strength of∼115.6 MPa,Young’s modulus of∼2.5 GPa,and glass transition temperature of 316°C.In the PI-CP plastic,the imine bonds are isolated within hydrophobic microenvironments generated by the rigid and hydrophobic polyimide chains and the benzene ring of cyclophosphazenes.As a result,the PI-CP plastics are highly stable in highly acidic and basic aqueous solutions and other commonly used organic solvents.The PI-CP plastic shows outstanding flame retardancy with a limiting oxygen index value of 48.8%.More importantly,the PI-CP plastic can be depolymerized to generate the original PI-NH_(2)and CPCHO monomers in high yields(∼97%)and purity.The recovered monomers can be used to refabricate the original plastics,establishing highly efficient polymer-monomer-polymer circulation and a sustainable plastics economy.展开更多
The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms.In the present study,...The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms.In the present study,the leaching of incorporated flame retardants (FRs),including polybrominated diphenyl ethers (PBDEs),alternative brominated FRs (AFRs),and phosphate flame retardants (PFRs),from different sizes of recycled acrylonitrile-butadiene-styrene (ABS) polymer were investigated in avian digestive fluids.The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored.In the recycled ABS,BDE 209 (715 μg/g) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE,1766 μg/g) had the highest concentrations among all target FRs.The leaching proportions of FRs were higher in finer sizes of ABS.The leaching proportions of FRs from recycled ABS increased with elevated logKow of FRs.In the tests with coexisted ABS and sediment,hexato deca-BDEs,BTBPE,and decabromodiphenyl ethane (DBDPE) migrated from ABS to sediment,which resulted in the less bioaccessible fractions of these FRs in gut fluids.More lipophilic chemicals tended to be adsorbed by sediment from ABS.The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids.The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds,and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.展开更多
基金financially supported from the National Natural Science Foundation of China(No.U23A20605)the University Synergy Innovation Program of Anhui Province,China(No.GXXT-2020-072)+2 种基金Anhui Jieqing Project,China(No.2208085J19)Anhui Graduate Innovation and Entrepreneurship Practice Project,China(No.2022cxcysj090)China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202202).
文摘A novel method was developed to enhance the utilization rate of steel slag(SS).Through treatment of SS with phosphoric acid and aminopropyl triethoxysilane(KH550),we obtained modified SS(MSS),which was used to prepare MSS/wood-plastic composites(MSS/WPCs)by replacing talcum powder(TP).The composites were fabricated through melting blending and hot pressing.Their mechanical and combustion properties,which comprise heat release,smoke release,and thermal stability,were systematically investigated.MSS can improve the mechanical strength of the composites through grafting reactions between wood powder and thermoplastics.Notably,MSS/WPC#50(16wt%MSS)with an MSS-to-TP mass ratio of 1:1 exhibited optimal comprehensive performance.Compared with those of WPC#0 without MSS,the tensile,flexural,and impact strengths of MSS/WPC#50 were increased by 18.5%,12.8%,and 18.0%,respectively.Moreover,the MSS/WPC#50 sample achieved the highest limited oxygen index of 22.5%,the highest vertical burning rating at the V-1 level,and the lowest horizontal burning rate at 44.2 mm/min.The formation of a dense and stable char layer led to improved thermal stability and a considerable reduction in heat and smoke releases of MSS/WPC#50.However,the partial replacement of TP with MSS slightly compromised the mechanical and flame-retardant properties,possibly due to the weak grafting caused by SS powder agglomeration.These findings suggest the suitability of MSS/WPCs for high-value-added applications as decorative panels indoors or outdoors.
基金supported by the National Natural Science Foundation of China(NSFC grant no.21935004).
文摘Traditional flame-retardant plastics are technically difficult to chemically recycle.The development of newtypes of flame-retardant plastics that are intrinsically capable of being closed-loop recycled and are sufficiently robust and stable to satisfy their practical application is urgently needed.In this study,closed-loop recyclable flame-retardant plastics with high mechanical strength and excellent chemical resistance are fabricated by cross-linking amino-terminated polyimide(PI-NH_(2))and aldehyde-terminated cyclophosphazene(CP-CHO)with imine bonds.The resultant flame-retardant plastic,which is denoted as PI-CP,exhibits a tensile strength of∼115.6 MPa,Young’s modulus of∼2.5 GPa,and glass transition temperature of 316°C.In the PI-CP plastic,the imine bonds are isolated within hydrophobic microenvironments generated by the rigid and hydrophobic polyimide chains and the benzene ring of cyclophosphazenes.As a result,the PI-CP plastics are highly stable in highly acidic and basic aqueous solutions and other commonly used organic solvents.The PI-CP plastic shows outstanding flame retardancy with a limiting oxygen index value of 48.8%.More importantly,the PI-CP plastic can be depolymerized to generate the original PI-NH_(2)and CPCHO monomers in high yields(∼97%)and purity.The recovered monomers can be used to refabricate the original plastics,establishing highly efficient polymer-monomer-polymer circulation and a sustainable plastics economy.
基金supported by the National Natural Science Foundation of China(Nos.41603085 and 41877361)the Natural Science Foundation of Guangdong Province(No.2016A030310440)+2 种基金the Pearl River S&T Nova Program of Guangzhou(No.201806010185)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z134)the Key Research Program of Frontier Sciences,the Chinese Academy of Science(No.QYZDJ-SSW-DQC018)
文摘The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms.In the present study,the leaching of incorporated flame retardants (FRs),including polybrominated diphenyl ethers (PBDEs),alternative brominated FRs (AFRs),and phosphate flame retardants (PFRs),from different sizes of recycled acrylonitrile-butadiene-styrene (ABS) polymer were investigated in avian digestive fluids.The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored.In the recycled ABS,BDE 209 (715 μg/g) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE,1766 μg/g) had the highest concentrations among all target FRs.The leaching proportions of FRs were higher in finer sizes of ABS.The leaching proportions of FRs from recycled ABS increased with elevated logKow of FRs.In the tests with coexisted ABS and sediment,hexato deca-BDEs,BTBPE,and decabromodiphenyl ethane (DBDPE) migrated from ABS to sediment,which resulted in the less bioaccessible fractions of these FRs in gut fluids.More lipophilic chemicals tended to be adsorbed by sediment from ABS.The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids.The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds,and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.
