Poly（1,4-Dioxan-2-one）or poly（p-dioxanone）,PPDO,was synthesized by ring-opening polymerization of 1,4-dioxan-2-one using Lanthanum isopropoxide（La（OiPr）3）as an initiator.The investigation showed that the react...Poly（1,4-Dioxan-2-one）or poly（p-dioxanone）,PPDO,was synthesized by ring-opening polymerization of 1,4-dioxan-2-one using Lanthanum isopropoxide（La（OiPr）3）as an initiator.The investigation showed that the reaction rate of polymerization,monomer conversion and molecular weight of PPDO were influenced dominantly by the ratio of monomer to initiator,reaction temperature and reaction time.PPDO with a weight-average molecular weight of 25200 and dispersity of 1.3 can be synthesized at 80℃ within 5 hours,and the corresponding conversion of monomer reach ac.90%.展开更多
MgO has been prepared by precipitation of magnesium nitrate solution with ammonium hydroxide,and the dechlorination abilities of the MgO for PP/PVC have been investigated.Moreover,effects of the MgO preparation condit...MgO has been prepared by precipitation of magnesium nitrate solution with ammonium hydroxide,and the dechlorination abilities of the MgO for PP/PVC have been investigated.Moreover,effects of the MgO preparation conditions,including types of washing solutions and calcination atmosphere on dechlorination behaviors of PP/PVC have been discussed.Results prove that the obtained MgO(washing solution: ethanol;calcinations atmosphere: nitrogen) possesses much higher dechlorination ability than that of commercial grade MgO,which exhibits dechlorination degree of PP/PVC as high as 95.71wt.%.展开更多
For the Poly(vinyl chloride)(PVC)/Poly(ethylene glycol)(PEG)/Potassium hydroxide(KOH)reaction system,effects of solvent type,PVC concentration and reaction time on dechlorination of PVC have been investigated.Results ...For the Poly(vinyl chloride)(PVC)/Poly(ethylene glycol)(PEG)/Potassium hydroxide(KOH)reaction system,effects of solvent type,PVC concentration and reaction time on dechlorination of PVC have been investigated.Results proved that the addition of solvents could effectively enhance the dechlorination of PVC for the PVC/PEG/KOH system.Moreover,the properties of solvents as well as the PVC concentration greatly influence the dechlorination behaviors of PVC.When the PVC concentration is less than 1.6 wt%,PVC owns higher dechlorination degree(DD)at 25℃in tetrahydrofuran(THF)than that in 1,4-dioxane(DOA),and the DD of PVC decreases with the increase of the PVC oncentration in both solvents;when the PVC concentration is higher than 1.6 wt%while less than 3.2 wt%,PVC owns higher dechlorination degree in DOA than that in THF,and the DD of PVC increases with the increase of the PVC oncentration in DOA;with further increase of PVC concentration,the DD of PVC decreases in both solvents.In addition,the DD of PVC first rapidly increase,then decrease slowly with the increase of reaction time for PVC/THF system,while it keeps on increasing for PVC/DOA system,suggesting the dechlorinated PVC is more stable in DOA.展开更多
文摘Poly（1,4-Dioxan-2-one）or poly（p-dioxanone）,PPDO,was synthesized by ring-opening polymerization of 1,4-dioxan-2-one using Lanthanum isopropoxide（La（OiPr）3）as an initiator.The investigation showed that the reaction rate of polymerization,monomer conversion and molecular weight of PPDO were influenced dominantly by the ratio of monomer to initiator,reaction temperature and reaction time.PPDO with a weight-average molecular weight of 25200 and dispersity of 1.3 can be synthesized at 80℃ within 5 hours,and the corresponding conversion of monomer reach ac.90%.
文摘MgO has been prepared by precipitation of magnesium nitrate solution with ammonium hydroxide,and the dechlorination abilities of the MgO for PP/PVC have been investigated.Moreover,effects of the MgO preparation conditions,including types of washing solutions and calcination atmosphere on dechlorination behaviors of PP/PVC have been discussed.Results prove that the obtained MgO(washing solution: ethanol;calcinations atmosphere: nitrogen) possesses much higher dechlorination ability than that of commercial grade MgO,which exhibits dechlorination degree of PP/PVC as high as 95.71wt.%.
文摘For the Poly(vinyl chloride)(PVC)/Poly(ethylene glycol)(PEG)/Potassium hydroxide(KOH)reaction system,effects of solvent type,PVC concentration and reaction time on dechlorination of PVC have been investigated.Results proved that the addition of solvents could effectively enhance the dechlorination of PVC for the PVC/PEG/KOH system.Moreover,the properties of solvents as well as the PVC concentration greatly influence the dechlorination behaviors of PVC.When the PVC concentration is less than 1.6 wt%,PVC owns higher dechlorination degree(DD)at 25℃in tetrahydrofuran(THF)than that in 1,4-dioxane(DOA),and the DD of PVC decreases with the increase of the PVC oncentration in both solvents;when the PVC concentration is higher than 1.6 wt%while less than 3.2 wt%,PVC owns higher dechlorination degree in DOA than that in THF,and the DD of PVC increases with the increase of the PVC oncentration in DOA;with further increase of PVC concentration,the DD of PVC decreases in both solvents.In addition,the DD of PVC first rapidly increase,then decrease slowly with the increase of reaction time for PVC/THF system,while it keeps on increasing for PVC/DOA system,suggesting the dechlorinated PVC is more stable in DOA.
