A Facile Synthesis and Structural Verification of Etorphine and Dihydroetorphine from Codeine

In this study, an improved process for the synthesis of etorphine and dihydroetorphine from codeine with an overall yield of 2.7% and 1.5% respectively is described. The structure of 19‐propylthevinol 7 was verfied by X‐ray structure analysis. This result is promising for synthesizing various morphine‐based drugs.     

Polyamide 6‐polycaprolactone multiblock copolymers: Synthesis,characterization, and degradation

This work describes the synthesis and characterization of polyamide 6 (PA 6)‐polycaprolactone (PCL) multiblock copolymers. Low molar mass, fully amine end‐capped PA 6 was prepared by the addition of a diamine monomer during ε‐caprolactam polymerization. A low molar mass PCL was selected to be incorporated as the biodegradable block and was fully end‐capped with toluene 2,4‐diisocyanate. End group analysis and molecular weight characterizations were performed for both end‐functionalized polymers by SEC, NMR and titration analysis. Incorporation of PCL into PA 6 was mainly achieved by solution mixing of the two end‐functional blocks and, was continued after the removal of the solvent with solid state polymerization (SSP) by gradual heating until about 40 °C below the melting temperature of the PA 6. Molecular weights started to grow immediately during solution mixing and only increased marginally during the SSP treatment. FTIR and SEC studies confirmed the reaction between the two components. DSC data, in combination with the enhanced molar mass during solution mixing pointed to a blocky microstructure, for which distinct melting and crystallization temperatures were observed for the PCL and the PA 6 blocks. Hydrolytic and enzymatic degradation studies were performed at 25 °C where the degree of degradation was followed by weight loss analysis, SEM and SEC. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis,characterization, and properties of tunable thermosensitive amphiphilic dendrimer‐star copolymers with Y‐shaped arms

Novel and well‐defined amphiphilic dendrimer‐star copolymer poly(ε‐caprolactone)‐block‐(poly(2‐(2‐methoxyethoxy)ethylmethacrylate‐co‐oligo(ethylene glycol) methacrylate))₂ with Y‐shaped arms were synthesized by the combination of ring‐opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The investigation of thermal properties and the analysis of crystalline morphology indicate that the high‐branched structure of dendrimer‐star copolymers with Y‐shaped arms and the presence of amorphous P(MEO₂MA‐co‐OEGMA) segments together led to the complete destruction of crystallinity of the PCL segments in the dendrimer‐star copolymer. In addition, the hydrophilicity–hydrophobicity transition of the dendrimer‐star copolymer film can be achieved by altering the external temperatures. The amphiphilic copolymers can self‐assemble into spherical nanomicelles in water. Because the lower critical solution temperature of the copolymers can be adjusted by varying the ratio of MEO₂MA and OEGMA, the tunable thermosensitive properties can be observed by transmittance, dynamic laser light scattering, and transmission electron microscopy (TEM). The release rate of model drug chlorambucil from the micelles can be effectively controlled by changing the external temperatures, which indicates that these unique high‐branched amphiphilic copolymers have the potential applications in biomedical field. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

抗粘、耐酸汽车钢化玻璃油墨的制备与性能

采取自制的调墨油、耐酸钢化颜料黑(低熔点玻璃粉和高温陶瓷黑色素的混合物)和助剂制备了抗粘、耐酸的汽车钢化玻璃油墨,进行了同步热分析,并采用SEM和XRD研究了烧结温度和时间对油墨釉层表面析晶、表面形貌及其对釉层光泽度和耐酸性的影响,确定了油墨的最佳烧结温度和时间.结果显示:低熔点玻璃粉的软化点为512℃,与调墨油树脂的最终分解温度(470℃)较接近,从而在600～700℃的烧结温度范围内可以充分熔融流动并代替树脂作为连结料;钢化颜料黑在579.4℃开始析晶,起到了降低油墨烧结温度和抗粘的作用;采用SEM和XRD研究了烧结温度和时间对油墨釉层表面析晶、表面形貌及对釉层光泽度和耐酸性的影响,确定了油墨的最佳烧结温度和时间分别为660℃和4 min;所制备的油墨具有良好的抗粘性、耐酸性以及较好的光泽度.     

CaSnO_3/膨润土复合光催化剂的制备及对亚甲基蓝的光催化降解性能

采用水热合成法制备出CaSnO3/膨润土复合光催化剂,采用XRD、SEM和IR等分析手段对该样品的形貌和结构进行表征,并研究了其对亚甲基蓝水溶液的光催化降解性能.结果表明:负载比例为3%的CaSnO3/膨润土复合光催化剂对亚甲基蓝水溶液的降解效果最好,当催化剂用量为60 mg,反应时间为14 min时,降解率可达98%.     

植物离体成花及其与整体成花的比较研究

成花机理问题长期以来受到人们的关注,不仅因为它是生物学的基本问题之一,而且因为成花生理研究的任何进展都将对生产实践产生特别重要的影响。目前,离体成花研究的报道大致反映了以下几方面的研究结果:(1)试管内培养物成花;(2)外植体种类和性状对成花的影响;(3)营养供应、外源激素和环境条件对试管成花的影响;(4)外植体培养物成花前后的内源多胺、激素、蛋白质、核酸等的变化。这表明离体成花研究的内容已经比较广泛而丰富,但人们还没有充分掌握外植体成花的规律。本文对离体成花的研究结果进行了比较系统的探讨,并与整体成花加以比较,以便进一步使离体实验能在成花研究中更好地发挥作用。     

气隙式膜蒸馏法分离浓缩透明质酸水溶液的研究

介绍了应用气隙式膜蒸馏分离技术对透明质酸热敏性水溶液的浓缩分离情况. 结果表明, 使用膜孔径为0.2μm的聚四氟乙烯微孔疏水膜可使原料液的浓度提高1.6倍以上, 透明质酸截留率为80%以上. 探讨了循环时间、平均温差、热侧温度等条件对分离效果的影响, 并讨论了膜蒸馏过程热效率的变化规律.     

时效对微晶Al—Si系合金α—Al相晶格常数的影响

研究了时效对微晶态Ａｌ－Ｓｉ二元合金和Ａｌ－Ｓｉ－Ｆｅ－Ｃｕ－Ｍｇ多元合金相组成、基体α－Ａｌ相晶格常数的影响。结果表明：时效初期合金中第二相质量分数明显增加，时效一定时间后，第二相质量分数不再变化，而α－Ａｌ相晶格常数一直增大，直至超过纯铝晶格常数值；两种合金时效１００ｈ后，晶格常数趋于一致。