Syntheses and Surface Properties of Polyacrylonitrile-based Copolymer Membranes Containing Sugar Moieties

Introduction Asatypeofwidelyusedmembranematerials, polyacrylonitrile(PAN)hasbeeninvestigatedby manyresearchersinthefieldsofpervaporation,ul- trafiltration,anddialysis[1_4].However,PAN- basedmembranesarerelativelyhydrophobicwitha lowbiocompatibility.Thesepropertieslimittheir furtherapplicationsinaqueoussolutionseparation andtheirusageasbiomedicaldevices.Muchatten- tionhasbeenpaidtoimprovingthecharacteristics ofPAN-basedmembranes.Thecopolymerization ofANwithhydrophilicmonomersisconsideredas…     

含金鸡纳碱的光活性聚合物──Ⅰ．金鸡纳碱／丙烯酰胺共聚物的合成与表征

研究了金鸡纳碱与丙烯酰胺的自由基共聚反应。发现在氯仿／乙醇混合溶剂中采用硫酸奎宁作为金鸡纳碱共聚单体可以合成收率和金鸡纳碱含量均较高的新型水溶性共聚物。对共聚物用元素分析、核磁共振、粘度和旋光度测定等方法进行表征，发现在假定丙烯酰胺链节为非光活性的条件下共聚物中金鸡纳碱链节的比旋光度随聚合配方中金鸡纳碱含量的增加而增加。     

Synthesis and physicochemical properties of copolymers of aniline and 3,4-ethylenedioxythiophene

Copolymers of various compositions have been synthesized via copolymerization of aniline with 3,4-ethylenedioxythiophene in the presence of a poly(4-styrenesulfonic acid) matrix, and a mechanism of copolymerization has been suggested. It has been shown that the synthesized copolymers are included in non-stoichiometric interpolyelectrolyte complexes with matrices stabilized by salt bonds and nonionic interactions. The copolymers of aniline and ethylenedioxythiophene possess electrical conductivity and can enter into redox and acid-base reactions.     

聚氯乙烯-丙烯酸丁酯接枝共聚物的结构表征

以通用聚氯乙烯(PVC)和脱氯化氢PVC树脂为基体,采用悬浮溶胀接枝共聚法合成聚氯乙烯-丙烯酸丁酯接枝共聚物,对脱氯化氢PVC和接枝共聚物的结构进行了表征.结果表明,以碱液为介质加热PVC能脱除少量氯化氢,得到以链节数为2,3,4的共轭双键为主的不饱和结构,而树脂的分子量变化不大;在相同接枝反应条件下,采用脱氯化氢PVC与丙烯酸丁酯接枝共聚可以提高接枝率和接枝效率;PVC接枝共聚物的特性粘度随接枝率增加而增加,其重均分子量和分子量分布指数均大于接枝所用的PVC树脂.     

Head-to-head vinyl polymers. V. Preparation and characterization of alternating head-to-head copolymers of alkyl acrylates with alkyl methacrylates

Alternating head-to-head (h-h) copolymers of methyl or n-butyl acrylates with the corresponding methacrylates were synthesized by alternating copolymerization of ethylene with citraconic anhydride, followed by esterification and Characterization. The respective equimolar (1:) head-to-tail (h-t) copolymers were also prepared by conventional radical copolymerization as comparison. The alternating, relatively low molecular weight h-h copolymers obtained showed softening, glass transition, and degradation temperatures somewhat higher than those displayed by the 1:1 h-t copolymers. After pyrolysis the main decomposition products from both h-h and h-t copolymers were alcohols, acrylates, and methacrylates. Furthermore, the ratios of alcohols to acrylates were larger for the h-h than for the h-t copolymers and smaller for the methyl than for the n-butyl esters.     

Functional copolymers with triazole and acetate fragments

New functional copolymers of different composition with triazole and acetate fragments in the macromolecules were synthesized by free radical copolymerization of 1-vinyl-1,2,4-triazole with vinyl acetate. The reactivity of the comonomers was studied and the monomer copolymerization constants were calculated. The structure and composition of the copolymers were determined by elemental analysis, IR and ¹H NMR spectroscopy.     

Synthesis of polystyrene-based cationic copolymers and their colloidal properties in water

A series of polystyrene-based cationic copolymers was synthesized by two different methods: (1) solution copolymerization of styrene and vinylbenzyl trimethylammonium chloride (VBTMAC) in ethanol, and (2) surfactant-free emulsion copolymerization of styrene and vinylbenzyl chloride in water followed by reaction with trimethylamine. The results indicated that the different synthesis methods would result in different polymer structures and, therefore, affect the solubility and colloidal properties of the copolymers in water. For the copolymers prepared by method 2, partial crosslinking was observed. The copolymers made by this method are almost water-insoluble. In contrast, the copolymers made from direct copolymerization of styrene and VBTMAC in ethanol are water-soluble or dispersible, but the solubility and the particle size of microaggregates formed by these copolymers in water strongly depend on charge density and temperature. One of the important results from this study is that uniform colloidal particles with a very small particle size (30–50 nm) can be obtained by dispersing polystyrene-based cationic copolymers in water without adding any surfactants. Received: 29 July 1998 Accepted in revised form: 28 September 1998     

N-苯基马来酰亚胺/对氯甲基苯乙烯活性可控超支化交替共聚合的研究

采用核磁共振氢谱, 研究了N-苯基马来酰亚胺(NPMI)与对氯甲基苯乙烯(PCMS)在氘代氯仿中的络合性能. 以PCMS作为引发剂单体, 通过原子转移自由基聚合(ATRP)引发NPMI-PCMS电子转移络合物(CTC)进行活性可控超支化共聚合. 考察了单体初始摩尔分数对共聚物组成和其玻璃化转变温度的影响, 用Kelen-Tudos法计算得到两种单体的竞聚率分别为 r_NPMI＝0.11和r_PCMS＝0.25. 结果表明, 当单体配比f_NPMI＝0.4～0.7时, 共聚物具有交替结构, 其耐热性随着NPMI含量的增加而提高. 此外还考察了溶剂、聚合温度等对共聚合反应动力学的影响. 并进一步用所得超支化交替共聚物作为大分子引发剂, 引发甲基丙烯酸甲酯(MMA)聚合, 制得了多臂超支化接枝共聚物 poly(NPMI-co-PCMS)/poly(MMA).     

GRAFTING OF ACRYLAMIDE ONTO SURFACE OF COPOLYMERS CONTAINING P-TOLYLCARBAMOYL PENDANT GROUP INITIATED WITH CERIC SALT

Two copolymers containing p-tolylcarbamoyl pendant group poly (MAMT-co-VAc) and poly(MAMT-co-MA) were synthesized f and the graft copolymerization of AAM onto these two func-tional copolymers films initiated with ceric salt were carried out in aqueous solution for variousperiods at 30℃. The formation of graft copolymer was verified by water absorption, ESCA andSEM photographs. Based on the results of the study of the initiation mechanism of model com-pounds and ceric salt systems, the reaction mechanism of the graft copolymerization initiated withceric salt was proposed.     

8-苯胺-1-萘磺酸钛配合物的合成及催化乙烯与降冰片烯共聚合反应

合成了新型催化剂8-苯胺-1-萘磺酸钛配合物, 并应用于乙烯与降冰片烯的共聚合反应中. 分别考察了助催化剂种类[甲基铝氧烷(MAO)和三乙基铝(TEA)]、 降冰片烯浓度、 Al/Ti摩尔比、 聚合温度和聚合压力对催化活性与共聚性能的影响. 通过核磁共振、示差扫描量热和凝胶渗透色谱等对所制备的共聚物进行了表征. 结果表明, 在相同条件下, 以MAO为助催化剂时, 共聚催化活性更高, 催化剂为单活性中心, 可得到分子量分布较窄(PDI≈3)的共聚产物, 其共聚反应机理为加成聚合. 另外, 随着降冰片烯浓度的升高, 共聚物中降冰片烯单元的摩尔比呈线性上升趋势, 所得共聚物的熔点随之降低.     

SYNTHESIS AND CHARACTERIZATION OF AMPHIPHILIC GRAFT COPOLYMER CONTAINING MICROPHASE SEPARATED AND LONG POLY(ETHYLENE OXIDE) SIDE CHAIN STRUCTURES**

Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called "selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed "comb- model" was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.     

Synthesis and Characterization of Amphiphilic Block Copolymer Containing PVP and Poly(5-benzyloxytrimethylene carbonate)

Amphiphilic block copolymers have attracted great interest recently, especially for thebiomedical uses1, . The hydrophilic blocks improve the biocompatibility of copolymer, 2while the hydrophobic blocks enhance the mechanics of the material and providever…     

聚环氧乙烷-g-聚己内酯两亲性接枝共聚物的合成及药物释放行为

通过环氧丙醇(GL)与环氧乙烷(EO)的阴离子顺序开环聚合制备了水溶性嵌段共聚物PEO-b-PGL, 以PGL嵌段每个重复单元的侧羟基为引发点进一步引发ε-己内酯(CL)的开环聚合, 合成了结构规整的以聚环氧乙烷(PEO)为主链的两亲性接枝共聚物(PEO-b-PGL-g-PCL). 研究了PEO-b-PGL-g-PCL在水相中的自组装行为, 采用稳态荧光探针法测定了胶束的临界胶束浓度(cmc). 以疏水性药物阿霉素(DOX)为模型药物, 研究了两亲性接枝共聚物的化学组成对药物的扩散释放以及降解释放行为的影响.     

聚(丙烯酸-co-甲氧基聚乙二醇甲基丙烯酸酯)梳状高分子的侧链结晶行为

以不同分子量的甲氧基聚乙二醇甲基丙烯酸酯(mPEG1000MA或mPEG2000MA)为大单体,与丙烯酸(AA)、甲基烯丙基磺酸钠(SMAS)等单体通过自由基聚合反应合成了一系列具有不同分子量、不同侧链长度、不同侧链密度的聚(丙烯酸-co-甲氧基聚乙二醇甲基丙烯酸酯)梳状高分子.用乌氏黏度计测定梳状高分子的特性黏数以表征其分子量大小.采用示差扫描量热法(DSC)测量梳状高分子中甲氧基聚乙二醇(mPEG)侧链的结晶温度和熔点.分析认为,当mPEG1000MA与AA共聚后,处于玻璃态的PAA主链对mPEG侧链的物理限制作用很大程度上影响了mPEG侧链的结晶行为.这种在受限环境中mPEG的结晶温度和结晶熔点均发生明显漂移,低于PEG在本体中的结晶.结晶温度和熔点的偏移受到主链长度、侧链疏密、侧链长度、磺酸侧基含量等诸多分子结构和组成因素的影响.研究结果表明:共聚物中侧链越稀疏,侧链结晶受限作用越明显;mPEG侧链分子量越大,其结晶受到主链的限制作用越弱;在梳状高分子主链上引入磺酸侧基官能团后,侧链的结晶的受限程度增加,并且由于非晶侧链的增多,表现出明显的侧链玻璃化转变.     

含氟丙烯酸酯共聚物结晶性与涂膜表面润湿性能研究

以甲基丙烯酸2-全氟辛基乙酯( FOEMA)分别和不同烷烃链长丙烯酸酯(RA,CH2=CHCOOCnH2n+1,n=4,8,12,16,18)为单体,用自由基聚合法合成了一系列的含氟丙烯酸酯共聚物,通过X射线衍射(XRD)和示差扫描量热法(DSC)对共聚物进行了表征,发现结晶性与丙烯酸酯的烷烃链长度密切相关,当n=4,...     

乳酸-3-苯甲基-2,5-吗啉二酮共聚物的合成及共聚物组分分析

以苯丙氨酸为原料合成3-苯甲基-2,5-吗啉二酮(PMD),以辛酸亚锡为催化剂,研究PMD与丙交酯(LA)开环共聚得到乳酸-3-苯甲基-2,5-吗啉二酮共聚物,用IR、1H-NMR、DSC对共聚物进行分析表征,表明可得到含有苯丙氨酸的聚乳酸共聚物.利用红外定量分析法替代1H-NMR法测定共聚物中PMD的组分含量,以1671.53cm-1和870.82cm-1两波数处特征峰的吸光度比值,作标准工作曲线Y=0.05567X+0.1091,r=0.9993.比较了催化剂浓度、反应时间、温度对共聚物组分含量、共聚物特性黏数[η]的影响.结果表明,低催化剂浓度条件下(0.025mol%与0.1mol%),产物特性黏数[η]随反应时间的延长先增加然后下降;而在高催化剂浓度(0.2mol%)的条件下,因主链中形成了更多更稳定的酰胺键,产物特性黏数[η]10h内维持不变;随PMD加入量的增多,进入共聚物中的PMD组分也相应地呈线性增加,但因PMD的开环活性低于丙交酯,所以苯丙氨酸引入聚乳酸链段中比较困难,但在低投料比条件下(<20mol%),升高反应温度有利于PMD含量的增加;同样也因为PMD在共聚物中组分含量的增多,苯环的稳定性使共聚物[η]受催化剂浓度及温度的影响逐渐减弱.     

含氟两亲接枝共聚物的制备及其与牛血清蛋白作用的研究

用端基反应法合成了对乙烯基苄基的聚乙二醇大分子单体,将该大分子单体与甲基丙烯酸六氟丁酯共聚,合成了一种含氟两亲接枝共聚物.利用1H-NMR1、9F-NMR、GPC对大分子单体和两亲接枝共聚物进行了表征.表面张力法测定了两亲接枝共聚物的临界胶束浓度,发现随着共聚物中含氟链段含量的增加,其临界胶束浓度降低.采用荧光光谱研究了含氟两亲接枝共聚物与牛血清蛋白(BSA)的相互作用,结果表明由于含氟链段疏水力的作用,含氟两亲接枝共聚物能与牛血清蛋白发生相互作用使其荧光增强,随着含氟两亲接枝共聚物浓度和共聚物中含氟链段含量的增加,荧光增强幅度加大.通过透射电子显微镜(TEM)和激光光散射粒度仪(PCS)测试发现,当BSA加入到含氟两亲接枝共聚物的胶束溶液后,所得胶束的粒径和粒径分布变大,共聚物胶束由规整的实心核壳结构变为囊泡状核壳结构.     

茂金属催化乙烯与降冰片烯共聚合研究

研究了茂金属催化体系Ｍｅ２ＳｉＣｐ２ＭＣｌ２／ＭＡＯ（Ｍ＝Ｚｒ，ｔｉ）催化乙烯与降冰片烯共聚合，考察了不同聚合条件下的共聚及乙烯动力学行为，对共聚物的结构进行了ＤＳＣ，１３Ｃ ＮＭＲ表征．研究表明，在相同的聚合条件下，Ｚｒ较Ｔｉ有更佳的共聚合催化性能．在相近的投料比条件下，得到了降冰片烯含量和Ｔｇ均较文献高的乙烯与降冰片烯的共聚物．     

Polyfluorenes containing pyrazine units:Synthesis,photophysics and electroluminescence

A series of conjugated copolymers of 9,9-dioctylfluorene and symmetrical pyrazine unit (BY) were synthesized by Suzuki copolymerization and were used as novel light-emitting materials in PLEDs.Efficient energy transfer was observed in both thin film and solution.Compared with the lowest occupied molecular orbital (LUMO) energy level of the polyfluorenes homopolymer (PFO),the lower LUMO energy levels of copolymers indicated that the introduction of the BY unit would be benefit to electron injection.The turn-...     

负载型钴二亚胺配合物-TiCl_4复合催化剂制备新型乙烯/1-丁烯共聚产物结构性能研究

合成了三种负载型二亚胺配体钴配合物 TiCl4复合催化剂 (CL1、CL2、CL3催化剂 ) .不用MAO ,以烷基铝为助催化剂 ,用它们催化乙烯 1 丁烯淤浆共聚合制备一系列塑性体和弹性体共聚物 .研究表明 ,复合催化剂性质受二亚胺配体性质影响 ,配体L1制备的复合催化剂具有低聚及原位共聚性能 ,可制得高支化度(36 0～ 6 1 5branchnumber 10 0 0C)低密度和极低密度 (0 885～ 0 910g cm3)塑性体和弹性体共聚物 .在 1 丁烯用量低于 5 %时 ,CL1催化剂制备的共聚产物中 1 丁烯含量超过投料比