The melting and recrystallization behaviour of poly（vinylcyclohexane）-b-poly（ethylene）-b-poly（vinylcyclohexane）（PVCH-PE-PVCH） triblock copolymer in supercritical carbon dioxide(CO2) was investigated by（using...The melting and recrystallization behaviour of poly（vinylcyclohexane）-b-poly（ethylene）-b-poly（vinylcyclohexane）（PVCH-PE-PVCH） triblock copolymer in supercritical carbon dioxide(CO2) was investigated by（using） of DSC.The effect of the rate of the depressurization of CO2 on the crystallization of the samples was also examined.It is found that there are three melting peaks on each DSC curve of the samples treated in supericritical CO2 at the temperature above tm of the untreated PVCH-PE-PVCH.They corresponded to the 'hard' confined crystallization of PE blocks homogeneous nucleation,the 'soft' confined crystallization of PE blocks homogeneous nucleation and the self-seeding nucleation free crystallization of PE blocks respectively.Furthermore,these three kinds of crystallization could be controlled by changing the competition between the crystallization of PE block and the vitrifaction of PVCH block in the samples,which depended on the rate of the depressurization of CO2.展开更多
The extraction method based on the reversible chemical complexation is highly effective and selective for separating polar organic solutes from dilute solutions,and the basicity of the extractant is one of the most im...The extraction method based on the reversible chemical complexation is highly effective and selective for separating polar organic solutes from dilute solutions,and the basicity of the extractant is one of the most important parameters affecting the extraction equilibrium.In this paper,the determination of basicity of Lewis basic extractant and its mixture solvent was first proposed on the basis of extraction behavior of HCl and the appropriate stoichiometric ratio of solute to extractant.The basicities of two Lewis basic chemicals,n-octy-lamine and di-n-butylamine,and some basicity of typical Lewis basic extractant mixture,trioctylamine(TOA)/1-octanol and trialkylphosphine oxide(TRPO)/kerosene,were measured at 25 ℃ by using this me-thod.The results show that this method was more accurate and simple,the basicity of Lewis basic chemicals was in agreement with the values reported in the literature,and the basicity of the mixture solvent depended on the extractant type and concentration.展开更多
文摘The melting and recrystallization behaviour of poly（vinylcyclohexane）-b-poly（ethylene）-b-poly（vinylcyclohexane）（PVCH-PE-PVCH） triblock copolymer in supercritical carbon dioxide(CO2) was investigated by（using） of DSC.The effect of the rate of the depressurization of CO2 on the crystallization of the samples was also examined.It is found that there are three melting peaks on each DSC curve of the samples treated in supericritical CO2 at the temperature above tm of the untreated PVCH-PE-PVCH.They corresponded to the 'hard' confined crystallization of PE blocks homogeneous nucleation,the 'soft' confined crystallization of PE blocks homogeneous nucleation and the self-seeding nucleation free crystallization of PE blocks respectively.Furthermore,these three kinds of crystallization could be controlled by changing the competition between the crystallization of PE block and the vitrifaction of PVCH block in the samples,which depended on the rate of the depressurization of CO2.
文摘The extraction method based on the reversible chemical complexation is highly effective and selective for separating polar organic solutes from dilute solutions,and the basicity of the extractant is one of the most important parameters affecting the extraction equilibrium.In this paper,the determination of basicity of Lewis basic extractant and its mixture solvent was first proposed on the basis of extraction behavior of HCl and the appropriate stoichiometric ratio of solute to extractant.The basicities of two Lewis basic chemicals,n-octy-lamine and di-n-butylamine,and some basicity of typical Lewis basic extractant mixture,trioctylamine(TOA)/1-octanol and trialkylphosphine oxide(TRPO)/kerosene,were measured at 25 ℃ by using this me-thod.The results show that this method was more accurate and simple,the basicity of Lewis basic chemicals was in agreement with the values reported in the literature,and the basicity of the mixture solvent depended on the extractant type and concentration.
