水溶性聚合物和两亲聚合物:9.新型丙烯酰胺基两亲单体及其两亲聚合物的单层膜研究

本文对新型两亲单体,2-丙烯酰胺基十六烷磺酸(AMC_(16)S),及其两亲聚合物PAMC_(16)S在空气-水界面上形成单层膜的特点进行了研究。AMC_(16)S可通过在亚相中添加Ca~(2+)或Cd~(2+)等多价阳离子在界面上原位生成不溶性磺酸盐的方法获得满意的成膜行为。PAMC_(16)S不溶于水,可直接成膜。发现,PAMC_(16)S的成膜行为与亚相的性质明显相关。纯水亚相下PAMC_(16)S的极限单体链节面积较大,如亚相含有Ca~(2+)或Cd~(2+),极限面积明显缩小,说明烷基碳氢链的排列趋向紧密。     

兼具有强阴离子性与疏水缔合性的丙烯酰胺三元共聚物

在微乳液介质中实施了丙烯酰胺 (AM)、苯乙烯 (St)、2 丙烯酰胺基 2 甲基丙磺酸钠 (NaAMPS)的共聚合 ,制备了既含有强阴离子性基团 (—SO3Na)又含有疏水基团 (St)的丙烯酰胺三元共聚物AM NaAMPS St;通过红外光谱法、紫外分光光度法及元素分析法对共聚物的结构及组成进行了表征 ;稀释外推粘度法测定了共聚物的特性粘数 ;测定了共聚物纯水溶液及盐水溶液的表观粘度 ;荧光探针法考察了三元共聚物的疏水缔合性以及离子基团对疏水缔合性的影响规律 .实验结果表明 ,在聚丙烯酰胺 (PAM )分子主链上同时引入强阴离子性基团与疏水基团后 ,阴离子的电粘效应与疏水基团的疏水缔合作用相互协同 ,会使共聚物水溶液的黏度显著提高 ;盐溶液对疏水缔合作用的增强效应与强阴离子基团对盐的较大容忍度相互结合 ,会使共聚物水溶液的抗盐性能明显得以提高 ;大分子链上的强阴离子基团磺酸根的存在 ,在一定程度上会削弱疏水基团之间的疏水缔合作用 ,即对疏水基团的疏水缔合行为会产生一定的负性影响 .     

一种两性三元共聚物的合成

选用聚乙二醇二丙烯酸酯(PEGDA)为扩链剂,以丙烯酰胺(AM)、2-甲基-2-丙烯酰胺基丙磺酸(AMPS)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为主单体,采用水溶液聚合方法合成了两性三元共聚物AM/AMPS/DMC;测定了共聚物的性能,并利用红外光谱研究了其分子结构.结果表明,所合成的共聚物具有良好的耐酸和高温稳定性,以及高抗剪切率.     

强阴离子型丙烯酰胺共聚物P(AM-co-NaAMPS)的结构与性能

在水介质中实施了丙烯酰胺 (AM)与 2 丙烯酰胺基 2 甲基丙磺酸钠 (NaAMPS)的溶液共聚合 ,制备了组成系列变化的强阴离子型共聚物P(AM co NaAMPS) ;通过红外光谱法与元素分析法对共聚物的组成进行了表征 ;稀释外推粘度法测定了共聚物的特性粘数及Huggins常数 ;测定了共聚物纯水溶液及盐水溶液的表观粘度及高温下共聚物盐水溶液的粘度保持率 ;重点考察了共聚物的结构与组成对其各种性能的影响规律 .实验结果表明 ,在聚丙烯酰胺 (PAM)分子主链上引入NaAMPS链节后 ,磺酸根的强阴离子性与庞大侧基的位阻效应 ,赋于共聚物P(AM co NaAMPS)以优良的溶解、增稠、耐温与抗盐性能 ,且这些性能随共聚物的结构与组成的改变发生规律性的变化 .     

丙烯酰胺—丙炮酸甲酯—2—丙烯酰胺基—2—甲基丙磺酸共聚物的合成及表征

以丙烯酰胺，丙烯酸甲酯和２－丙烯酰胺基－２－甲基丙磺酸为原料，通过水溶液共聚，合成了一种新的三元共聚物。研究了影响共聚反应的因素，并对其结构进行了表征。     

聚(2-丙烯酰胺基-2-甲基丙磺酸/丙烯酰胺)水凝胶合成与性能研究

以2-丙烯酰胺基-2-甲基丙磺酸和丙烯酰胺为原料,以PEG6000为成孔剂,采用水溶液法合成多孔性聚(2-丙烯酰胺基-2-甲基丙磺酸/丙烯酰胺)水凝胶,研究了凝胶的溶胀性和电场作用下的退溶胀性能.在凝胶制备过程中,PEG6000分子充当成孔剂,通过综合性能比较和红外光谱测试可知,所得凝胶具有多孔结构,这种孔洞结构有利于水分子的进出.结果显示,当引发剂为0.005 mol/L,交联剂为0.008 mol/L,摩尔比AMPS:PEG6000=100∶1,AMPS:AAm=2∶1时,可得综合性能较好的PAMA凝胶.     

丙烯酰胺型阴离子表面活性单体与丙烯酰胺共聚物水溶液的流变特性

以丙烯酰胺型阴离子表面活性单体2-丙烯酰胺基十四烷基磺酸钠(NaAMC14S)为共单体,与丙烯酰胺(AM)的水溶液均相共聚合,使NaAMC14S的浓度分别处于临界胶束浓度上下,分别制备了具有无规结构与微嵌段结构的两类共聚物;用红外光谱法对共聚物的结构进行了表征,使用乌氏粘度法测定了特性粘数,相对表示出了共聚物的分子量;采用荧光探针法与表观粘度法重点研究了两类共聚物的疏水缔合性与水溶液的流变特性.研究结果表明,具有微嵌段结构的共聚物具有很强的疏水缔合性,当其水溶液的浓度达0.2wt%后,表观粘度迅速提高;其水溶液的切力变稀行为具有明显的可逆性,表现出强的抗剪切性能.本研究中特别发现,具有微嵌段结构的共聚物其盐水溶液的表观粘度远高于纯水溶液的表观粘度,当共聚物浓度为0.3wt%、CaCl2浓度为2wt%时,溶液的表观粘度竟然提高了3个数量级,表现出独特的正性盐敏性(即遇盐变稠).     

丙烯酰胺－丙烯酸甲酯－2－丙烯酰胺基－2－甲基丙磺酸共聚物的合成及表征

以丙烯酰胺（ＡＭ），丙烯酸甲酯（ＭＡ）和２－丙烯酰胺基－２－甲基丙磺酸（ＡＭＰＳ）为原料，通过水溶液共聚，合成了一种新的三元共聚物。研究了影响共聚反应的因素，并对其结构进行了表征。     

AM/SAMPS反相乳液聚合产物的表征

用过硫酸铵 (NH4 S2 O8)为引发剂 ,失水山梨醇酐单油酸酯 (Span - 80 )为乳化剂 ,合成了丙烯酰胺 (AM) / 2-丙烯酰胺基 - 2 -甲基丙磺酸钠 (SAMPS)反相乳液聚合产物 ,测试了该共聚物的红外光谱、和热性能 ,讨论反应温度、SAMPS、以及乳化剂浓度对分子量的影响     

(2-甲基丙烯酰氧乙基)三甲基氯化铵-丙烯酰胺双水相共聚合

将(2-甲基丙烯酰氧乙基)三甲基氯化铵(DMMC)与丙烯酰胺(AM)在聚乙二醇(PEG)水溶液中进行双水相共聚合(ATPC),并与DMMC/AM均相水溶液共聚合(HASC)进行比较.在均相水溶液共聚合体系中得到了DMMC/AM共聚体系的竞聚率分别为rDMMC=1.77、rAM=0.32,并给出了竞聚率的95%,99%联合置信区域.比较了两种共聚合体系的转化率-时间曲线和共聚组成,表明双水相共聚合体系初期反应速率高于均相水溶液共聚合体系,但最终转化率相似;两种共聚合体系得到的共聚物组成有较大差别.测得了DMMC、AM以及DMMC-AM共聚物(CPAM)在65℃、反应条件下的相分配系数为K1=0.035、K2=0.125和Kp=0.011.结合双水相聚合的本质以及单体和共聚物在两相的分配系数,提出了一个计算双水相共聚组成的新方法,用该方法计算的双水相共聚合体系的共聚组成与实验点吻合较好.     

聚烯丙基氯化铵模板对AM/AA共聚物结构的影响

采用IR,1H-NMR和13C-NMR研究了聚烯丙基氯化铵(PAAC)模板对丙烯酰胺(AM)/丙烯酸(AA)共聚产物结构的影响,发现这种模板对共聚物P(AM/AA)序列结构和分子量有重要影响.由于共聚合体系中AA单体在PAAC模板聚合物上预组装,使得模板体系共聚物比无模板体系共聚物的AA和AM序列长度显著增加.这种类似多嵌段结构得到pKa′测定的进一步验证.另外模板分子量大小,模板和AA单体摩尔比,AM和AA摩尔比对共聚物结构的影响也进行了研究.应当指出这种模板聚合产物分离模板后仍有少量不能分离掉的PAAC聚合物存在.     

表面活性单体AMC14AB在水溶液中的聚合动力学研究

采用溴酸钾-溴化钾法研究了阳离子型表面活性单体(2-丙烯酰胺基)乙基十四烷基二甲基溴化铵(AMC14AB)在水溶液中的聚合动力学,分别考察了引发剂浓度与单体浓度对聚合速率的影响,确定了聚合速率方程,分析了聚合机理,考察了温度对聚合反应的影响,测定了聚合表观活化能。研究结果表明,由于AMC14AB在水溶液中的胶束化行为,使其具有较快的聚合速率,于60℃下聚合,40min内转化率即可达到80%以上;AMC14AB的聚合速率方程为Rp=k[M]0.92[I]0.48,说明链终止为双基终止方式,引发过程与单体无关;聚合表观活化能为80.72kJ/mol。     

DNA sequencing by capillary electrophoresis using copolymers of acrylamide and N,N-dimethylacrylamide

Copolymers of acrylamide (AM) and N,N-dimethylacrylamide (DMA) with AM to DMA molar ratios of 3:1, 2:1 and 1:1 and molecular weights of about 2.2 MDa were synthesized. The polymers were tested as separation media in DNA sequencing analysis by capillary electrophoresis (CE). The dynamic coating ability of polydimethylacrylamide (PDMA) and the hydrophilicity of polyacrylamide (PAM) have been successfully combined in these random copolymers. A separation efficiency of over 10 million theoretical plates per meter has been reached by using the bare capillaries without the additional polymer coating step. Under optimized separation conditions for longer read length DNA sequencing, the separation ability of the copolymers decreased with decreasing AM to DMA molar ratio from 3:1, 2:1 and 1:1. In comparison with PAM, the copolymer with a 3:1 AM:DMA ratio showed a higher separation efficiency. By using a 2.5% w/v copolymer with 3:1 AM:DMA ratio, one base resolution of 0.55 up to 699 bases and 0.30 up to 963 bases have been achieved in about 80 min at ambient temperatures.     

丙烯酰胺/2-丙烯酰胺基十六烷磺酸铵无规共聚物的形态结构研究

 本工作应用透射电子显微镜研究了丙烯酰胺/2-丙烯酰胺基十六烷磺酸铵无规共聚物(AM/AMC₁₆SNH₄)的形态结构.给出共聚物在水溶液中具有伸展网状结构,并存在一定程度的疏水基因间的缔合作用.是一种在耐盐性和储存稳定性方面有明显改善的新型改性聚丙烯酰胺.     

二乙基二烯丙基氯化铵均聚及其与丙烯酰胺或丙烯酸共聚动力学研究

采用膨胀计法研究了以过硫酸铵为引发剂,二乙基二烯丙基氯化铵(DEDAAC)在水溶液中的均聚及其与丙烯酰胺(AM)和丙烯酸(AA)共聚动力学,测定了相应的聚合表观活化能;采用元素分析法测定了DEDAAC分别与AM和AA在低转化率下共聚物的组成,并采用氯离子选择性电极法测定了DEDAAC-AM共聚物中的氯离子含量,按Kelen-Tudos方法求得了相应的竞聚率.结果表明,DEDAAC均聚速率方程为RP=k[M]0.99[I]0.76,表观活化能Ea=77.00kJ/mol,说明链终止为单基终止和双基终止并存,引发过程与单体浓度无关;DEDAAC与AM在摩尔比为4∶1时,共聚动力学方程为RP=[M]2.53[I]0.90,表观活化能Ea=67.06kJ/mol,单体竞聚率为rDE=0.31±0.02、rAM=5.27±0.53;DEDAAC与AA在摩尔比为4∶1时,共聚动力学方程为RP=k[M]2.94[I]0.83,表观活化能Ea=70.07kJ/mol,竞聚率为rDE=0.28±0.03、rAA=5.15±0.28;DEDAAC与AM和AA等共聚为非理想共聚,得到的产物均为无规共聚物.     

Amphiphilic Poly(4‐acryloylmorpholine)/Poly[2‐(N‐carbazolyl)ethyl acrylate] Random and Block Copolymers Synthesized by NMP

A series of random copolymers and block copolymers containing water‐soluble 4AM and fluorescent VAK are synthesized by NMP. The homopolymerizations of 4AM and VAK and 4AM/VAK random copolymerization are performed in 50 wt% DMF using 10 mol% SG1, resulting in a linear increase in versus conversion, and final polymers with narrow molecular weight distributions ( < 1.4). Reactivity ratios r_VAK = 0.64 ± 0.52 and r_4AM = 0.86 ± 0.66 are obtained for the 4AM/VAK random copolymerization. In addition, a poly(4AM) macroinitiator is used to initiate a surfactant‐free suspension polymerization of VAK. After 2.5 h, the resulting amphiphilic block copolymer has = 12.6 kg · mol^?1, = 1.48, molar composition F_VAK = 0.38 with latex particle sizes between 270 and 475 nm.

     

Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and rDE and rNaAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.     

SYNTHESIS AND CHARACTERIZATION OF A NOVEL FLUORINE-CONTAINING HYDROPHOBICALLY ASSOCIATING POLYMER*

In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer withacrylamide is reported. 2 -perfluoroamyl -4- hydroxylquinoline 2 was synthesized from ethyl 2, 2 -dihydro-perfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in highyields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer wereinvestigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that therheological properties of aqueous solutions of polyacrylamide were modified significantly when a smallproportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles,pseudoplasticity of these solutions and the effect of the presence of surfactant These results could beexplained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of thesecopolymers.     

Modeling random methyl branching in ethylene/ propylene copolymers using metathesis chemistry: synthesis and thermal behavior

The structure of random ethylene/propylene (EP) copolymers has been modeled using step polymerization chemistry. Six ethylene/propylene model copolymers have been prepared via acyclic diene metathesis (ADMET) polymerization and characterized for primary and higher level structure using in-depth NMR, IR, DSC, WAXD, and GPC analysis. These copolymers possess 1.5, 7.1, 13.6, 25.0, 43.3, and 55.6 methyl branches per 1000 carbons. Examination of these macromolecules by IR and WAXD analysis has demonstrated the first hexagonal phase in EP copolymers containing high ethylene content (90%) without the influence of sample manipulation (temperature, pressure, or radiation). Thermal behavior studies have shown that the melting point and heat of fusion decrease as the branch content increases. Further, comparisons have been made between these random ADMET EP copolymers, random EP copolymers made by typical chain addition techniques, and precisely branched ADMET EP copolymers.     

含有吡啶环的可溶型聚苯并咪唑共聚物的合成及表征

采用溶液缩聚法合成了不同摩尔比的3,3′-二氨基联苯二胺(DAB)、2,3,5,6-四氨基吡啶(TAP)盐酸盐和4,4′-二羧基二苯醚(DCDPE)的共聚物。用红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)、热重分析(TGA)以及电子拉力机对聚合物的结构和性能进行了表征。结果表明:共聚反应中,当TAP在两种胺类单体中的摩尔分数分别为0.1、0.2、0.3时,30℃的特性黏度对应为0.806、0.8161、.028 dL/g。共聚物在N,N-二甲基酰胺(DMF)、二甲基亚砜(DMSO)、N-甲基-2-吡咯烷酮(NMP)等极性溶剂和浓H2SO4中有良好的溶解性。3种单体可以在短时间内形成共聚产物,产物具有良好的成膜性、热稳定性和力学性能。