Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes...Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.展开更多
The ethylenediamine-functionalized resin-supported Pd（0） complex was prepared from PdCl2 and ethylenediamine-functionalized chloromethylated polystyrene, followed by reduction with KBH4. The complex was characterize...The ethylenediamine-functionalized resin-supported Pd（0） complex was prepared from PdCl2 and ethylenediamine-functionalized chloromethylated polystyrene, followed by reduction with KBH4. The complex was characterized by FT-IR, XRD, BET, SEM and EDS. The resin-supported catalyst exhibited high catalytic activity in the Heck reaction and could be reused up to 17 times in NMP or 16 times in DMF at 90 ℃ in the Heck reaction of iodobenzene with acrylic acid. The leaching investigation disclosed that the palladium leaching was caused by the interaction of iodobenzene with the metal Pd（0） on supported catalyst. The leached palladium species in filtrate was very stable and could be reused five times after the solid catalyst was filtered off. A cross-transfer test in recycling in the presence of additional carbon disclosed that the soluble leached palladium species had much higher catalytic activity than supported and/or adsorbed palladium in solid-solution heterogeneous Heck reaction.展开更多
目的评价乙二胺四乙酸(EDTA)和次氯酸钠(NaClO)对自粘接树脂水门汀与牙本质间粘接强度的影响。方法选择新鲜无龋、无裂纹的人离体前磨牙27颗,去除颊侧釉质,暴露浅层牙本质,随机分为对照组(A组)、EDTA组(B组)和NaClO组(C组)。分别选用蒸...目的评价乙二胺四乙酸(EDTA)和次氯酸钠(NaClO)对自粘接树脂水门汀与牙本质间粘接强度的影响。方法选择新鲜无龋、无裂纹的人离体前磨牙27颗,去除颊侧釉质,暴露浅层牙本质,随机分为对照组(A组)、EDTA组(B组)和NaClO组(C组)。分别选用蒸馏水、3%EDTA溶液和1%NaClO溶液处理牙本质表面后与自粘接树脂水门汀Rely X Unicem进行粘接,将其中24个试件置于37℃生理盐水中浸泡24 h后测定剪切强度,采用SPSS 17.0统计学软件对数据进行统计分析,在扫描电镜(SEM)和体视显微镜下分别观察粘接界面及断裂模式。结果 A组与B组的剪切强度分别为(8.55±0.63)MPa和(8.47±0.56)MPa,二者间差异无统计学意义(P>0.05);C组的剪切强度为(12.97±0.59)MPa,与A组和B组间差异均有统计学意义(P<0.05)。SEM下观察可见,C组自粘接树脂水门汀Rely X Unicem与牙本质间结合紧密,但均未见树脂突,而A组与B组粘接界面均不理想。体视显微镜下观察可见,A组与B组试件破坏模式以内聚破坏为主,C组试件全部为内聚破坏。结论 1%Na Cl O处理牙本质可以提高自粘接树脂水门汀Rely X Unicem与牙本质之间的粘接强度,3%EDTA处理对提高自粘接树脂水门汀Rely X Unicem与牙本质之间的粘接强度无影响。展开更多
A novel aliphatic sulfonie acid ion exchange resin was prepared from ethylenediamined polystyrene(PS-acyl-EDA),2-acrylamido-2-methylproanesulfonic acid(AMPS)by Michael reaction.This kind of resin has a longer chain th...A novel aliphatic sulfonie acid ion exchange resin was prepared from ethylenediamined polystyrene(PS-acyl-EDA),2-acrylamido-2-methylproanesulfonic acid(AMPS)by Michael reaction.This kind of resin has a longer chain than conventional sulphonic polystyrene resin,that is,the former is easier to react with other compound.The effect of the reaction time,reaction temperature,catalyst amount,reagent amount and the charge ration on reaction result were discussed.Under the optimum condition,the maximum loading of the sulfonie acid ion exchange resin could be up to 1.15 mmol·g-1 resin.The product was characterized with FT-IR.The filling material of chromatographic column could be prepared by this method.展开更多
文摘Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.
文摘The ethylenediamine-functionalized resin-supported Pd（0） complex was prepared from PdCl2 and ethylenediamine-functionalized chloromethylated polystyrene, followed by reduction with KBH4. The complex was characterized by FT-IR, XRD, BET, SEM and EDS. The resin-supported catalyst exhibited high catalytic activity in the Heck reaction and could be reused up to 17 times in NMP or 16 times in DMF at 90 ℃ in the Heck reaction of iodobenzene with acrylic acid. The leaching investigation disclosed that the palladium leaching was caused by the interaction of iodobenzene with the metal Pd（0） on supported catalyst. The leached palladium species in filtrate was very stable and could be reused five times after the solid catalyst was filtered off. A cross-transfer test in recycling in the presence of additional carbon disclosed that the soluble leached palladium species had much higher catalytic activity than supported and/or adsorbed palladium in solid-solution heterogeneous Heck reaction.
文摘目的评价乙二胺四乙酸(EDTA)和次氯酸钠(NaClO)对自粘接树脂水门汀与牙本质间粘接强度的影响。方法选择新鲜无龋、无裂纹的人离体前磨牙27颗,去除颊侧釉质,暴露浅层牙本质,随机分为对照组(A组)、EDTA组(B组)和NaClO组(C组)。分别选用蒸馏水、3%EDTA溶液和1%NaClO溶液处理牙本质表面后与自粘接树脂水门汀Rely X Unicem进行粘接,将其中24个试件置于37℃生理盐水中浸泡24 h后测定剪切强度,采用SPSS 17.0统计学软件对数据进行统计分析,在扫描电镜(SEM)和体视显微镜下分别观察粘接界面及断裂模式。结果 A组与B组的剪切强度分别为(8.55±0.63)MPa和(8.47±0.56)MPa,二者间差异无统计学意义(P>0.05);C组的剪切强度为(12.97±0.59)MPa,与A组和B组间差异均有统计学意义(P<0.05)。SEM下观察可见,C组自粘接树脂水门汀Rely X Unicem与牙本质间结合紧密,但均未见树脂突,而A组与B组粘接界面均不理想。体视显微镜下观察可见,A组与B组试件破坏模式以内聚破坏为主,C组试件全部为内聚破坏。结论 1%Na Cl O处理牙本质可以提高自粘接树脂水门汀Rely X Unicem与牙本质之间的粘接强度,3%EDTA处理对提高自粘接树脂水门汀Rely X Unicem与牙本质之间的粘接强度无影响。
文摘A novel aliphatic sulfonie acid ion exchange resin was prepared from ethylenediamined polystyrene(PS-acyl-EDA),2-acrylamido-2-methylproanesulfonic acid(AMPS)by Michael reaction.This kind of resin has a longer chain than conventional sulphonic polystyrene resin,that is,the former is easier to react with other compound.The effect of the reaction time,reaction temperature,catalyst amount,reagent amount and the charge ration on reaction result were discussed.Under the optimum condition,the maximum loading of the sulfonie acid ion exchange resin could be up to 1.15 mmol·g-1 resin.The product was characterized with FT-IR.The filling material of chromatographic column could be prepared by this method.
