The possibility of mesoporous acid solid as a carder for metallocene catalyst in ethylene polymerization and catalyst for polyethylene （PE） catalytic degradation was investigated. Here, HMCM-41 and AIMCM-41, and mes...The possibility of mesoporous acid solid as a carder for metallocene catalyst in ethylene polymerization and catalyst for polyethylene （PE） catalytic degradation was investigated. Here, HMCM-41 and AIMCM-41, and mesoporous silicoaluminophosphate molecular sieves （SAPO1 and SAPO2） were synthesized and used as acid solid. Much more gases were produced during catalytic degradation in PE/acid solid mixtures via in situ polymerization than those via physical mixing. The particle size distribution results exhibited that the particle size of SAPO1 in the PE/SAPOI mixture via in situ polymerization was about 1/14 times of that of the original SAPO1 or SAPO1-supported metallocene catalyst. This work shows a novel technology for chemical recycling of polyolefin.展开更多
Hot stamping of high strength steels is defined as a process in which blank is heated to the temperature of the austenite stabilization region for a definite time and then formed and quenched simultaneously in a mold ...Hot stamping of high strength steels is defined as a process in which blank is heated to the temperature of the austenite stabilization region for a definite time and then formed and quenched simultaneously in a mold with cooling channels. During this process,the processing parameters of austenite temperature and soaking time have strong effects on the mechanical properties such as quenching hardness,tensile strength and elongation. Hence,it is necessary to investigate the relationship between the mechanical properties and the two processing parameters. In this paper,the orthogonal experiment with two factors and five levels was applied, and the experimental data based on the orthogonal experiment was acquired. Based on the data,regression models were set up and the results of the analysis of variance( ANOVA) showed that it is reliable to predict the quenching hardness,tensile strength and elongation by the regression models. Besides,the optimal results of each single object were obtained based on response surface methodology( RSM),and global optimums was gained by employing ideal point method in which the quenching hardness,and tensile strength and elongation were considered simultaneously.展开更多
A one-pot procedure for the synthesis of polyethylene tethered on multi-walled carbon nanotubes by in situ ethylene copolymerization with an olefin-type comonomer, tr-alkene functionalized multi-walled carbon nanotub...A one-pot procedure for the synthesis of polyethylene tethered on multi-walled carbon nanotubes by in situ ethylene copolymerization with an olefin-type comonomer, tr-alkene functionalized multi-walled carbon nanotubes （MW- CH = CH2） is reported. The covalent linkage between polyethylene and multi-walled carbon nanotubes is demonstrated. The MWCNTs are chemically oxidized first by a strong oxidizing agent and then functionalized with chlorocarbonyl groups （MW--COC1） via reacting with thionyl chloride. The MW--CH=CH2 are obtained by esterification of co-undecylenyl alcohol with MW--COCI. The MW--CH = CH2 may serve as olefin-type comonomers to fiLrther synthesize core-shell structured copolymers with a multi-walled carbon nanotubes core grafted with side chains of polyethylene via rac-（en）（THInd）2ZrC12 copolymerization catalyst. The core-shell structured nanocomposites were characterized by means of 1H-NMR, SEM, FTIR and TGA. The results confirmed the formation of polyethylene chains growing from the surface of multi-walled carbon nanotubes.展开更多
基金the support of the National Natural Science Foundation of China （No. 20174039） the Ministry of Science and Technology of China （No. 2005CB623800）.
文摘The possibility of mesoporous acid solid as a carder for metallocene catalyst in ethylene polymerization and catalyst for polyethylene （PE） catalytic degradation was investigated. Here, HMCM-41 and AIMCM-41, and mesoporous silicoaluminophosphate molecular sieves （SAPO1 and SAPO2） were synthesized and used as acid solid. Much more gases were produced during catalytic degradation in PE/acid solid mixtures via in situ polymerization than those via physical mixing. The particle size distribution results exhibited that the particle size of SAPO1 in the PE/SAPOI mixture via in situ polymerization was about 1/14 times of that of the original SAPO1 or SAPO1-supported metallocene catalyst. This work shows a novel technology for chemical recycling of polyolefin.
基金Sponsored by Automotive High-strength Stell Stampings Thermoforming Process(Grant No.10211653)
文摘Hot stamping of high strength steels is defined as a process in which blank is heated to the temperature of the austenite stabilization region for a definite time and then formed and quenched simultaneously in a mold with cooling channels. During this process,the processing parameters of austenite temperature and soaking time have strong effects on the mechanical properties such as quenching hardness,tensile strength and elongation. Hence,it is necessary to investigate the relationship between the mechanical properties and the two processing parameters. In this paper,the orthogonal experiment with two factors and five levels was applied, and the experimental data based on the orthogonal experiment was acquired. Based on the data,regression models were set up and the results of the analysis of variance( ANOVA) showed that it is reliable to predict the quenching hardness,tensile strength and elongation by the regression models. Besides,the optimal results of each single object were obtained based on response surface methodology( RSM),and global optimums was gained by employing ideal point method in which the quenching hardness,and tensile strength and elongation were considered simultaneously.
基金supported by the Science Foundation of Jiangsu University of Science and Technology(No.35061005)the Natural Science Foundation of Jiangsu Province of China(No.BK2012278)
文摘A one-pot procedure for the synthesis of polyethylene tethered on multi-walled carbon nanotubes by in situ ethylene copolymerization with an olefin-type comonomer, tr-alkene functionalized multi-walled carbon nanotubes （MW- CH = CH2） is reported. The covalent linkage between polyethylene and multi-walled carbon nanotubes is demonstrated. The MWCNTs are chemically oxidized first by a strong oxidizing agent and then functionalized with chlorocarbonyl groups （MW--COC1） via reacting with thionyl chloride. The MW--CH=CH2 are obtained by esterification of co-undecylenyl alcohol with MW--COCI. The MW--CH = CH2 may serve as olefin-type comonomers to fiLrther synthesize core-shell structured copolymers with a multi-walled carbon nanotubes core grafted with side chains of polyethylene via rac-（en）（THInd）2ZrC12 copolymerization catalyst. The core-shell structured nanocomposites were characterized by means of 1H-NMR, SEM, FTIR and TGA. The results confirmed the formation of polyethylene chains growing from the surface of multi-walled carbon nanotubes.
