EFFECTS OF L-PHENYLALANINE ON THE RADIATION SYNTHESIS OF POLY(N,N''''-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE)(MICRO)GELS

The effects of L-phenylalanine(L-Phe)on the synthesis of poly(N,N'-methylenebisacrylamide-co-4-vinylpyridine) (poly(Bis-co-4-VP))(micro)gels by γ-ray irradiation were studied.The addition of L-Phe could not only decrease the gelation dose(D_g)of the synthesis obviously,but also transform the morphology of copolymer from microgel to gel.In addition,the swelling ability of the(micro)gels was also affected in the presence of L-Phe.The decrease of D_g was ascribed to the effect of pH,while the transformation of the morphology was ascribed to the effect of L-Phe on the stability of the poly(Bis-co-4-VP)microgel.Such an effect was confirmed further as compared with the effects of L-alanine,L-glutamic acid,L-arginine,sulfuric acid and aqueous ammonia.     

STABILITY OF POLY（N,N＇-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE） MICROGEL DISPERSION AND ADJUSTMENT OF THE HYDROPHOBICITY IN THE MICROGELS

In the UV-Vis spectra of pure light-scattering systems, there is an exponential relationship between absorbance and wavelength （A = Kλ^-n）. Here, the exponent n is named as flocculation-coagulation parameter. In the present paper, the effects of different additives on the stability of poly（N,N＇-methylenebisacrylamide-co-4-vinylpyridine） （poly（Bis-co-4-VP）） microgel dispersion were studied in detail via this parameter. The results showed that the stability of the dispersion mainly comes from the ionization of pyridine groups, making the microgel positively charged on its surface. This was confirmed by the measurement of Zeta potential and the result of conductometric titration. The result of fluorescence analysis indicated that the hydrophobicity in the microgels is enhanced with the increase in total 4-VP unit content.     

NOVEL HYPERBRANCHED POLY（PHENYLENE OXIDE）S WITH PHENOLIC TERMINAL GROUPS： EFFECTS OF REACTION TIME AND CORE MOLECULES ON THE MOLECULAR WEIGHT AND POLYDISPERSITY

A novel hyperbranched poly（phenylene oxide） （HPPO） with phenolic terminal groups was prepared from 4-bromo-4＇,4＂-dihydroxytriphenylmethane as AB2 monomer in dimethylsulfoxide （DMSO） via a modified Ullmann reaction. The molecular weight and polydispersity （PD） of the resulting polymers increased with increasing reaction time. In the presence of core molecules （bisphenol A and 1,3,5-trihydroxybenzene）, which have the similar molecular backbones to the reactive monomer, the molecular weight could be controlled by varying the core-to-monomer ratio. Incorporation of a very small amount of core molecules could lead to a higher molecular weight as compared with that without the addition of core molecules. However, when the core content reached certain extent, the molecular weight would decrease with the further increase in the core content. A new similar behavior of control over the PD was also obtained. The resulting polymers were characterized by ^1H-NMR, ^13C-NMR, FT-IR, and GPC.     

STUDIES ON THE PRENYLFLAVOIDS PART Ⅹ Ⅵ SYNTHESIS OF （±）－3＇， 4＇－METHYLENEDIOXYISODERICINE－A AND （±）－PONGAPINONE－B

ＳＴＵＤＩＥＳＯＮＴＨＥＰＲＥＮＹＬＦＬＡＶＯＩＤＳＰＡＲＴⅩⅥＳＹＮＴＨＥＳＩＳＯＦ（±）－３＇，４＇－ＭＥＴＨＹＬＥＮＥＤＩＯＸＹＩＳＯＤＥＲＩＣＩＮＥ－ＡＡＮＤ（±）－ＰＯＮＧＡＰＩＮＯＮＥ－Ｂ￥ＸｉａｎＹｏｎｇＢＵ；ＬｉａｎＹｕｎＺＨＡＯａｎ...     

RAPID SYNTHESIS OF NOVEL OPTICALLY ACTIVE POLY（AMIDE-IMIDE）S DERIVED FROM N,N′-（PYROMELLITOYL）-BIS-L-ALANINE DIACID CHLORIDE AND HYDANTOIN DERIVATIVES UNDER MICROWAVE IRRADIATION

Eight novel poly(amide-imide)s were synthesized under microwave irradiation by using a domestic microwaveoven from the polycondensation reactions of N,N′-(pyromellitoyl)-bis-L-alanine diacid chloride (1) with eight different derivatives of hydantoin compounds (2a-h) in the presence of a small amount of a polar organic medium such as o-cresol. The polycondensation proceeded rapidly, compared with the conventional solution polycondensation and was completed within 8-10min, producing a series of new poly(amide-imide)s (3a-h) with inherent viscosities about 0.35-0.68dL/g in high yields. The obtained PAIs (3a-h) were fully characterized by means of FT-IR spectroscopy, elemental analyses, inherent viscosity (ηinh), solubility and specific rotation measurements. All of the resulting polymers show optical rotation and are optically active. Thermal properties of the poly(amide-imide)s were investigated by using thermal gravimetric analysis(TGA).     

STUDIES ON THE SYNTHESIS AND REACTIONS OF N－（1－OXO－4－CARBONYL－2，6，7－TRIOXA－1－PHOSPHABICYCLO ［2．2．2］ OCTANE）－N＇－ARYL THIOUREAS

ＳＴＵＤＩＥＳＯＮＴＨＥＳＹＮＴＨＥＳＩＳＡＮＤＲＥＡＣＴＩＯＮＳＯＦＮ－（１－ＯＸＯ－４－ＣＡＲＢＯＮＹＬ－２，６，７－ＴＲＩＯＸＡ－１－ＰＨＯＳＰＨＡＢＩＣＹＣＬＯ［２．２．２］ＯＣＴＡＮＥ）－Ｎ’－ＡＲＹＬＴＨＩＯＵＲＥＡＳＹｕＧｕｉＬＩ；Ｘｕ...     

水下超疏油聚(3,4-乙烯基二氧)噻吩薄膜的制备

以离子液体溴化(1-己基-3-甲基咪唑盐)作为电解质和掺杂剂采用电化学一步法制备了微纳米复合结构的聚(3,4-乙烯基二氧噻吩)薄膜, 薄膜由槽内排布着纳米珠链的棒状结构组成. 研究表明, 通过控制电流密度的大小, 可以调节棒状结构和珠状结构的平均直径. 离子液体中的咪唑阳离子和对阴离子均掺杂到聚合物中, 该薄膜具有可逆的电化学活性及水下超疏油特性.     

水下超疏油聚(3,4-乙烯基二氧)噻吩薄膜的制备简

以离子液体溴化(1-己基-3-甲基咪唑盐)作为电解质和掺杂剂采用电化学一步法制备了微纳米复合结构的聚(3,4-乙烯基二氧噻吩)薄膜,薄膜由槽内排布着纳米珠链的棒状结构组成. 研究表明,通过控制电流密度的大小,可以调节棒状结构和珠状结构的平均直径. 离子液体中的咪唑阳离子和对阴离子均掺杂到聚合物中,该薄膜具有可逆的电化学活性及水下超疏油特性.     

Bola型表面活性剂N,N′-二苯丙氨酸酰基-1,8-辛二胺的合成及性质研究

以L-苯丙氨酸为亲水部分和1,8-辛二胺为疏水部分,通过酯化生成酰胺和HCl脱去BOC保护基两步反应,合成一种新型Bola型表面活性剂N,N′-二苯丙氨酸酰基-1,8-辛二胺(DAOPh),采用IR、质谱和~1H NMR对其结构进行了表征.应用酸碱滴定法测得其pKa,采用电导率法、表面张力和芘荧光探针法测定了DAOPh水溶液的临界胶束浓度(CMC),进而预测其在水溶液中的聚集行为,探讨其作为药物载体的潜在优势.     

聚烯丙基胺硅胶复合材料的合成及其吸附性能

氯丙基三氯硅烷-硅胶;聚烯丙基胺硅胶复合材料的合成及其吸附性能     

四(4-重氮基苯基)卟啉的合成及其与聚苯乙烯磺酸钠自组装的研究

卟啉是一类重要的功能性小分子染料,近年来,在光化学治疗^[1,2]、光电转换^[3,4]、传感元件^[5]、烯烃环氧化催化剂^[6]和光敏化剂^[7]等方面的研究与应用引起了人们的广泛注意.通过两亲卟啉分子衍生物,或带有负电荷的卟啉衍生物,特别是带磺酸基的卟啉分子与正离子聚电解质自组装,制备带有卟啉结构单元的LB膜和自组装膜已有很多报道^[8～14].     

四臂聚乳酸/线性聚乳酸共混物的结晶行为及机理研究

为了探究四臂聚乳酸对线性聚乳酸结晶行为的影响,将四臂聚乳酸与线性聚乳酸的共混物在示差扫描量热仪(DSC)和偏振光显微镜(PLM)热台中加热到熔点附近的不同温度下恒温后分别进行了降温—升温程序,考察了四臂聚乳酸对线性聚乳酸的结晶行为的影响.结果表明,随着四臂聚乳酸含量增加,四臂聚乳酸在共混物形成的晶体中的比例增大且四臂聚乳酸有促进共混物晶体完善的作用,导致了熔融过程中熔点的上升.进一步研究证明,在共混物中完全熔融的四臂聚乳酸的支化结构能够促进结晶成核点的形成,从而促进四臂聚乳酸/线性聚乳酸共混物的结晶;而部分熔融的四臂聚乳酸能大幅促进共混物的结晶能力,这是未完全熔融的晶体的成核作用所导致的.     

稀土对氢氧化铝凝胶加热转变过程的影响

采用TG DTG DSC热分析、X射线衍射物相分析等方法研究了稀土元素对氢氧化铝凝胶加热转变过程的影响。实验结果表明 :稀土的添加加速了非晶Al2 O3的形成 ;提高了非晶态Al2 O3的晶化温度 ;对γ Al2 O3向α Al2 O3转变的影响随稀土添加种类及添加量不同而不同 ,添加的 4种稀土元素对该转变的抑制作用由强到弱为 :La >(Y ,Nd) >Ce。对稀土作用机制的初步分析结果表明 :稀土添加减少了Al2 O3中残余的羟基 ,因而降低了晶化过程中铝离子的扩散速率 ,从而减少了γ Al2 O3的晶化速率 ;稀土对γ Al2 O3向α Al2 O3转变的抑制作用主要是由于稀土铝酸盐的形成 ,LaAl1 1 O1 8(磁铅石结构 )的形成能更有效地抑制γ Al2 O3向α Al2 O3的转变 ,而YAlO3和NdAlO3的抑制作用则较小 ,以氧化物形式沉淀出来的CeO2 对γ Al2 O3向α Al2 O3转变没有明显影响