Thermogravimetric study of medical transfusion tube （MTT） waste containing polyvinyl chloride （PVC） was carried out using the thermogravimetric analyser （TGA） with N2, at different heating rates of 5, 10, 20, 30...Thermogravimetric study of medical transfusion tube （MTT） waste containing polyvinyl chloride （PVC） was carried out using the thermogravimetric analyser （TGA） with N2, at different heating rates of 5, 10, 20, 30, 50 ℃/min. The purpose is to obtain pyrolysis characteristics and kinetic parameters of medical waste. The experimental results indicate that the pyrolysis behavior of the MTT sample is in agreement with its main ingredient of PVC, appearing two stair stepping stages. The influence of the additives in MTT on pyrolysis behavior was also revealed, which could improve MTT pyrolysis at lower temperature in the first stage, and cause obvious unsmoothness and asymmetry of the second DTG peak. Four n-order kinetic models of Coats-Redfern, Ozawa, Kissinger and Freeman-carroll were used to get the kinetic parameters. Furthermore, a novel ＂two-step four-reaction model＂ was established to simulate the whole continuous process. The different methods and the kinetic parameters thus obtained were discussed and compared with each other in literatures. The reasons of deviation among kinetic values were tried to be elucidated. The new established model could more satisfactorily describe the pyrolysis process of MTT, being more mechanistic and conveniently serving for the engineering.展开更多
A novel type of thermal stabilizer-lanthanum tris (mono- i -octyl phthalate) (LTMP) was synthesized by double-decomposition reaction o f sodium mono- i -octyl phthalate with lanthanum chloride at 60 ℃. Sodium m ono- ...A novel type of thermal stabilizer-lanthanum tris (mono- i -octyl phthalate) (LTMP) was synthesized by double-decomposition reaction o f sodium mono- i -octyl phthalate with lanthanum chloride at 60 ℃. Sodium m ono- i -octyl phthalate was prepared by sodium hydrate and mono- i -octy l phthalate prepared by reaction of isooctyl alcohol and phthalic anhydride in th e presence of sulfuric acid catalyst at 110 ℃. The yield of lanthanum tris (mon o- i -octyl phthalate) is about 84.5%. Its thermal stabilities were measured by heat-ageing oven test when incorporated into PVC. The experimental results show that the heat stability time is about 40min at 190 ℃ when adding 3phr (pe r hundred resin) to PVC. The thermal stability of this product is better than th at of Ca-Zn complex and basic lead salt stabilizers, and equal to that of dibut yltin dilaurate.展开更多
Antimony mercaplde heat stabilizer for polyvinyl chlorideis synthesized from antimony trioxide and mercaptocarboxylic acid esters, HS(CH2).COoi-C8H17 (n=1～2) at 100～115 C In the presence of 0. 5%～1 % an organic aci...Antimony mercaplde heat stabilizer for polyvinyl chlorideis synthesized from antimony trioxide and mercaptocarboxylic acid esters, HS(CH2).COoi-C8H17 (n=1～2) at 100～115 C In the presence of 0. 5%～1 % an organic acid catalyst. Some physicochemicalconstants of the compounds, such as density and refractive index, aredetermined. The complexes are hydrolabll in aqueous solutions andthe bond of Sb-S is weaker than that of Sb-o. The forming bondproperty of antimony tris (mercaptoacid ester ) has been elucidatedby measurement of infrared spectra in comparison with mercaptocarboxylic acid esters. The polyvinyl chloride resins containing antimony mercaptide heat stabilizers, do not darken at elevated temperatures and exhibit a high degree of stability. It is proposed that mercaptocarboxylic acid ester freeradicals can esterify PVC microradicals at carbon atoms with upaired electrons.展开更多
基金Project(50378062) supported by the National Natural Science Foundation of ChinaProject(09JCYBJC08100) supported by the Natural Science Foundation of Tianjin City,China
文摘Thermogravimetric study of medical transfusion tube （MTT） waste containing polyvinyl chloride （PVC） was carried out using the thermogravimetric analyser （TGA） with N2, at different heating rates of 5, 10, 20, 30, 50 ℃/min. The purpose is to obtain pyrolysis characteristics and kinetic parameters of medical waste. The experimental results indicate that the pyrolysis behavior of the MTT sample is in agreement with its main ingredient of PVC, appearing two stair stepping stages. The influence of the additives in MTT on pyrolysis behavior was also revealed, which could improve MTT pyrolysis at lower temperature in the first stage, and cause obvious unsmoothness and asymmetry of the second DTG peak. Four n-order kinetic models of Coats-Redfern, Ozawa, Kissinger and Freeman-carroll were used to get the kinetic parameters. Furthermore, a novel ＂two-step four-reaction model＂ was established to simulate the whole continuous process. The different methods and the kinetic parameters thus obtained were discussed and compared with each other in literatures. The reasons of deviation among kinetic values were tried to be elucidated. The new established model could more satisfactorily describe the pyrolysis process of MTT, being more mechanistic and conveniently serving for the engineering.
文摘A novel type of thermal stabilizer-lanthanum tris (mono- i -octyl phthalate) (LTMP) was synthesized by double-decomposition reaction o f sodium mono- i -octyl phthalate with lanthanum chloride at 60 ℃. Sodium m ono- i -octyl phthalate was prepared by sodium hydrate and mono- i -octy l phthalate prepared by reaction of isooctyl alcohol and phthalic anhydride in th e presence of sulfuric acid catalyst at 110 ℃. The yield of lanthanum tris (mon o- i -octyl phthalate) is about 84.5%. Its thermal stabilities were measured by heat-ageing oven test when incorporated into PVC. The experimental results show that the heat stability time is about 40min at 190 ℃ when adding 3phr (pe r hundred resin) to PVC. The thermal stability of this product is better than th at of Ca-Zn complex and basic lead salt stabilizers, and equal to that of dibut yltin dilaurate.
文摘Antimony mercaplde heat stabilizer for polyvinyl chlorideis synthesized from antimony trioxide and mercaptocarboxylic acid esters, HS(CH2).COoi-C8H17 (n=1～2) at 100～115 C In the presence of 0. 5%～1 % an organic acid catalyst. Some physicochemicalconstants of the compounds, such as density and refractive index, aredetermined. The complexes are hydrolabll in aqueous solutions andthe bond of Sb-S is weaker than that of Sb-o. The forming bondproperty of antimony tris (mercaptoacid ester ) has been elucidatedby measurement of infrared spectra in comparison with mercaptocarboxylic acid esters. The polyvinyl chloride resins containing antimony mercaptide heat stabilizers, do not darken at elevated temperatures and exhibit a high degree of stability. It is proposed that mercaptocarboxylic acid ester freeradicals can esterify PVC microradicals at carbon atoms with upaired electrons.
