Effect of inorganic salts on viscosities of dimethyl sulphoxide(DMSO)solutions of acrylonitrile(AN)/ N vinylpyrrolidone( N VP) copolymer was discussed Viscosity was determined by revolving viscosimeter It was shown th...Effect of inorganic salts on viscosities of dimethyl sulphoxide(DMSO)solutions of acrylonitrile(AN)/ N vinylpyrrolidone( N VP) copolymer was discussed Viscosity was determined by revolving viscosimeter It was shown that solution viscosity decreased quickly with addition of KCl and NaCl and the effect of NaCl was more prominent than KCl As the concentration of KCl and NaCl beyond 0 025 mol·L -1 , the viscosity tended to increase The viscosity increased considerably with addition of FeCl 3 and CuCl 2 The change of solution viscosity became less obvious with addition of ZnCl 2 With increasing temperature, the viscosity of copolymer solution containing NaCl decreased most quickly and the copolymer solution containing FeCl 3 decreased most展开更多
The pyrolysis reaction of acrylonitrile(AN)/N-vinylpyrrolidone(N-VP) copolymer in air was studied with DSC. The apparent activation energy of pyrolysis reaction of copolymer was calculated by the Kissinger method. The...The pyrolysis reaction of acrylonitrile(AN)/N-vinylpyrrolidone(N-VP) copolymer in air was studied with DSC. The apparent activation energy of pyrolysis reaction of copolymer was calculated by the Kissinger method. The effect of different copolymerization conditions on the apparent activation energy of copolymer was discussed. It was found that with an increase of DMSO concentration in mixture solvent,the degradation apparent activation energy rose rapidly. When the weight ratio of N-VP/AN was less than 5/95, the apparent activation energy of degradation reduced quickly with the comononer N-VP concentration rising, and when the ratio was more than 5/95, the apparent activation energy became almost constant. When the copolymerization temperature rose, the apparent activation energy also increased.展开更多
文摘以γ射线引发顺丁烯二酸β-环糊精酯(CDM)和N-乙烯基吡咯烷酮(NVP)发生自由基链式反应,制备了顺丁烯二酸β-环糊精酯-N-乙烯基吡咯烷酮聚合物(CDM-NVP)。优化后的CDM-NVP聚合物的合成条件为:CDM∶NVP为1∶0.7(w/w,CDM 3.6 g和NVP 2.52 g),辐照剂量4 k Gy,DMF溶液用量为20 m L。在此条件下制备聚合物的产率为84%,重均分子量为20 k Da。结果表明,此聚合物可以同纳他霉素(NM)和多菌灵(MBC)形成稳定复合物。研究了复合物抑菌活性,测定了其表观稳定常数。利用紫外光谱、核磁图谱和相溶解度对药物复合物进行结构表征。303 K下,NM-CDM-NVP和MBC-CDM-NVP复合物的表观稳定系数分别为12988.54和865.94 L/mol。抑菌实验结果表明,NM-CDM-NVP和MBC-CDM-NVP复合物可以显著提高NM和MBC的溶解性和抑菌活性。
文摘Effect of inorganic salts on viscosities of dimethyl sulphoxide(DMSO)solutions of acrylonitrile(AN)/ N vinylpyrrolidone( N VP) copolymer was discussed Viscosity was determined by revolving viscosimeter It was shown that solution viscosity decreased quickly with addition of KCl and NaCl and the effect of NaCl was more prominent than KCl As the concentration of KCl and NaCl beyond 0 025 mol·L -1 , the viscosity tended to increase The viscosity increased considerably with addition of FeCl 3 and CuCl 2 The change of solution viscosity became less obvious with addition of ZnCl 2 With increasing temperature, the viscosity of copolymer solution containing NaCl decreased most quickly and the copolymer solution containing FeCl 3 decreased most
文摘The pyrolysis reaction of acrylonitrile(AN)/N-vinylpyrrolidone(N-VP) copolymer in air was studied with DSC. The apparent activation energy of pyrolysis reaction of copolymer was calculated by the Kissinger method. The effect of different copolymerization conditions on the apparent activation energy of copolymer was discussed. It was found that with an increase of DMSO concentration in mixture solvent,the degradation apparent activation energy rose rapidly. When the weight ratio of N-VP/AN was less than 5/95, the apparent activation energy of degradation reduced quickly with the comononer N-VP concentration rising, and when the ratio was more than 5/95, the apparent activation energy became almost constant. When the copolymerization temperature rose, the apparent activation energy also increased.
