Comprehensive Summary:Recycling polyolefin and other plastic mixtures encounters significant obstacles due to the intricate nature and economic inefficiencies of physically separating vast streams of mixed waste.Incor...Comprehensive Summary:Recycling polyolefin and other plastic mixtures encounters significant obstacles due to the intricate nature and economic inefficiencies of physically separating vast streams of mixed waste.Incorporating compatibilizers emerges as a viable strategy to diminish interfacial energy and bolster compatibility,ultimately yielding homogeneous products.In this contribution,polar polyolefins featuring metal dynamic cross-linking networks were synthesized by tandem polymerizing ionic cluster type polar monomers and olefins.Subsequent treatment with HCl aqueous solution and esterification with polyester precursors yields high-performance grafted polar polyolefins for mixed polymer compatibilizing.For PP/PC melting blends,adding 5 wt%of graft-modified polyolefin results in tougher blends that surpass the performance of corresponding virgin iPP in elongation at break(εb).Polar polyolefins containing sodium carboxylate groups play a dual role in compatibilizing PET/HDPE blends,acting both as compatibilizers and nucleating agents.Moreover,this strategy enables the production of grafted polyolefins comprising ternary polymers,which can be employed in compatibilizing ternary blends.展开更多
Graft-modified polybutadiene(PB) latex was synthesized and used as an admixture to improve the performance of oilwell cement. Results showed that the addition of latex to pure cement slurry can significantly reduce th...Graft-modified polybutadiene(PB) latex was synthesized and used as an admixture to improve the performance of oilwell cement. Results showed that the addition of latex to pure cement slurry can significantly reduce the fluid loss of the cement slurry. When the dosage was 8%, the fluid loss was only 38 mL, and the fluidity of the cement slurry was improved. With an increasing amount of latex, the fluidity of the cement slurry increased continuously. The toughness of cement was significantly enhanced, whose average elastic modulus was 4.2 GPa. Scanning electron microscopy revealed that the filter cake of the cement slurry with latex was thin and dense, and the surface was coated with a layer of latex film. The microstructure of the cement stone showed a high density, and an interweaving mesh network formed in the cement. The results of cement hydration heat analysis and X-ray diffraction showed that latex inhibited the hydration of cement; the effect was stronger under a larger amount of latex. It is indicated that the graft-modified PB latex has great potential to replace the conventional styrene-butadiene rubber(SBR) latex for cementing in the future.展开更多
基金supported by National Key R&D Program of China(No.2021YFA1501700)National Natural Science Foundation of China(No.52373002).
文摘Comprehensive Summary:Recycling polyolefin and other plastic mixtures encounters significant obstacles due to the intricate nature and economic inefficiencies of physically separating vast streams of mixed waste.Incorporating compatibilizers emerges as a viable strategy to diminish interfacial energy and bolster compatibility,ultimately yielding homogeneous products.In this contribution,polar polyolefins featuring metal dynamic cross-linking networks were synthesized by tandem polymerizing ionic cluster type polar monomers and olefins.Subsequent treatment with HCl aqueous solution and esterification with polyester precursors yields high-performance grafted polar polyolefins for mixed polymer compatibilizing.For PP/PC melting blends,adding 5 wt%of graft-modified polyolefin results in tougher blends that surpass the performance of corresponding virgin iPP in elongation at break(εb).Polar polyolefins containing sodium carboxylate groups play a dual role in compatibilizing PET/HDPE blends,acting both as compatibilizers and nucleating agents.Moreover,this strategy enables the production of grafted polyolefins comprising ternary polymers,which can be employed in compatibilizing ternary blends.
基金supported by the National Science and Technology Major Project of China (No. 2016ZX05020-004)
文摘Graft-modified polybutadiene(PB) latex was synthesized and used as an admixture to improve the performance of oilwell cement. Results showed that the addition of latex to pure cement slurry can significantly reduce the fluid loss of the cement slurry. When the dosage was 8%, the fluid loss was only 38 mL, and the fluidity of the cement slurry was improved. With an increasing amount of latex, the fluidity of the cement slurry increased continuously. The toughness of cement was significantly enhanced, whose average elastic modulus was 4.2 GPa. Scanning electron microscopy revealed that the filter cake of the cement slurry with latex was thin and dense, and the surface was coated with a layer of latex film. The microstructure of the cement stone showed a high density, and an interweaving mesh network formed in the cement. The results of cement hydration heat analysis and X-ray diffraction showed that latex inhibited the hydration of cement; the effect was stronger under a larger amount of latex. It is indicated that the graft-modified PB latex has great potential to replace the conventional styrene-butadiene rubber(SBR) latex for cementing in the future.
