Lactide was synthesized using lactic acid and stannous octoate as raw material and catalyst, respectively. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was prepared by lactide and poly (ethylene glycol) (PEG) via...Lactide was synthesized using lactic acid and stannous octoate as raw material and catalyst, respectively. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was prepared by lactide and poly (ethylene glycol) (PEG) via ring-opening polymerization. The most appropriate technological conditions of synthesis of lactide were researched in the paper. The copolymers were measured by Infrared spectroscopy (IR) and <sup>1</sup>H nuclear magnetic resonance (<sup>1</sup>H NMR). The results proved that the lactide and PLA-PEG were synthesized successfully. Hydrophilic performance of the copolymer was measured by a water contact angle tester after prepared into a flat membrane. The water contact angle changed from 81.5? to 71.6?, which proved that the hydrophily of PLA-PEG was better than PLA.展开更多
选择甲酰胺作磁性Fe3O4微晶的分散剂，通过设计反相悬浮聚合体系，合成了粒径分布窄、球状亲水性含环氧基磁性聚合物（MGM）．利用扫描电子显微镜（SEM）、红外光谱（FT-IR）、X射线粉末衍射仪（XRD）、振动样品磁强计（VSM）和低温N2...选择甲酰胺作磁性Fe3O4微晶的分散剂，通过设计反相悬浮聚合体系，合成了粒径分布窄、球状亲水性含环氧基磁性聚合物（MGM）．利用扫描电子显微镜（SEM）、红外光谱（FT-IR）、X射线粉末衍射仪（XRD）、振动样品磁强计（VSM）和低温N2吸附以及化学分析方法对聚合物进行了性能表征．结果表明，合成的MGM呈球形，且粒度分布较窄，粒径为0．13，0．28mm的粒子占91％；甲酰胺分散Fe3O4，微晶表面的亲水性进一步增强，单体甲基丙烯酸缩水甘油酯和N，N＇-亚甲基双丙烯酰胺交联共聚生成的胶粒能够包埋Fe3O4微晶形成胶核，胶核聚集形成均匀、稳定的MGM微球．MGM中Fe3O4含量为6．17％时，比饱和磁化强度σ．达6．5emu／g；其比表面积、平均孔径和孔容分别为117．6m^2／g，15．6nm和0．46cm^3/g，表面环氧基团含量为0．53mmol／g．MGM借助自身的活性环氧基团在十分温和的条件下共价偶联青霉素酰化酶（penicillin G acylase EC 3．5．1．11，简称PGA），制备的固定化酶在37℃下催化水解青霉素G钾生成6-氨基青霉烷酸（6-APA）的表观活性达502IU／g，并且在使用过程中投有出现磁聚集现象．展开更多
文摘Lactide was synthesized using lactic acid and stannous octoate as raw material and catalyst, respectively. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was prepared by lactide and poly (ethylene glycol) (PEG) via ring-opening polymerization. The most appropriate technological conditions of synthesis of lactide were researched in the paper. The copolymers were measured by Infrared spectroscopy (IR) and <sup>1</sup>H nuclear magnetic resonance (<sup>1</sup>H NMR). The results proved that the lactide and PLA-PEG were synthesized successfully. Hydrophilic performance of the copolymer was measured by a water contact angle tester after prepared into a flat membrane. The water contact angle changed from 81.5? to 71.6?, which proved that the hydrophily of PLA-PEG was better than PLA.
文摘选择甲酰胺作磁性Fe3O4微晶的分散剂，通过设计反相悬浮聚合体系，合成了粒径分布窄、球状亲水性含环氧基磁性聚合物（MGM）．利用扫描电子显微镜（SEM）、红外光谱（FT-IR）、X射线粉末衍射仪（XRD）、振动样品磁强计（VSM）和低温N2吸附以及化学分析方法对聚合物进行了性能表征．结果表明，合成的MGM呈球形，且粒度分布较窄，粒径为0．13，0．28mm的粒子占91％；甲酰胺分散Fe3O4，微晶表面的亲水性进一步增强，单体甲基丙烯酸缩水甘油酯和N，N＇-亚甲基双丙烯酰胺交联共聚生成的胶粒能够包埋Fe3O4微晶形成胶核，胶核聚集形成均匀、稳定的MGM微球．MGM中Fe3O4含量为6．17％时，比饱和磁化强度σ．达6．5emu／g；其比表面积、平均孔径和孔容分别为117．6m^2／g，15．6nm和0．46cm^3/g，表面环氧基团含量为0．53mmol／g．MGM借助自身的活性环氧基团在十分温和的条件下共价偶联青霉素酰化酶（penicillin G acylase EC 3．5．1．11，简称PGA），制备的固定化酶在37℃下催化水解青霉素G钾生成6-氨基青霉烷酸（6-APA）的表观活性达502IU／g，并且在使用过程中投有出现磁聚集现象．
