基于酶引发的温敏聚合物的合成与性能

以2-甲基-2-丙烯酸-2-(2-甲氧基乙氧基)乙酯(MEO2MA)和低聚乙二醇甲醚甲基丙烯酸酯(OEGMA₅₀₀)为单体,利用辣根过氧化物酶(HRP)/乙酰丙酮(ACAC)/H2O2三元催化体系引发自由基聚合,合成了温敏无规共聚物P(MEO2MA-co-OEGMA₅₀₀)。通过GPC、1HNMR、FTIR、DSC等对合成聚合物的数均分子量、分子量分布、结构及热性能进行了表征。通过测定聚合物溶液在不同温度下的透光率和粒径对聚合物的温敏性能进行了表征。制备了n(MEO2MA)∶n(OEGMA₅₀₀)分别为100∶0、95∶5、93∶7、90∶10、85∶15的温敏聚合物。结果表明,随着单体OEGMA₅₀₀投料占比的增加,合成聚合物的低临界溶解温度(LCST)从24℃增加至39℃,聚合物玻璃化转变温度(Tg)从–11.75℃逐渐降低至–14.74℃;LCST随聚合物水溶液浓度增加而降低;升高温度,聚合物平均粒径增加,比低温条件下聚合物平均粒径大82.5～135.6 nm。     

缩醛化乙烯醇-丙烯酸钠共聚物的合成及温敏性质

首先合成了室温下可溶于水的聚乙烯醇-丙烯酸钠共聚物(PVA-co-AANa),然后部分缩醛后得到一系列不同缩醛度(DA)、不同相对分子质量和单体组成的高分子材料(APVA-co-AANa),该材料具有温敏性。用FTIR和1HNMR表征了其结构。通过APVA-co-AANa水溶液在不同温度的浊度测定,考察了母体PVA-co-AANa相对分子质量、DA和单体组成对APVA-co-AANa的低临界溶解温度(LCST)的影响,发现APVA-co-AANa的DA越高、分子链越长、AA组分用量越小,相对LCST越低。而且,APVA-co-AANa水溶液还表现出盐敏性,LCST随NaCl用量增加而降低。APVA-co-AANa膜的AFM表面形貌的变化也证实了APVA-co-AANa的温敏性。     

酶催化水溶性导电聚苯胺的模板导向合成与表征

对辣根过氧化物酶(HRP)催化水溶性导电聚苯胺的合成进行了研究.以聚乙烯磺酸钠(PVS)作为反应的聚阴离子模板.详细地研究了反应体系的pH值、H2O2浓度及苯胺与PVS的摩尔比对苯胺聚合的影响.用UV-vis-near-IR、FTIR及四探针电导率测试仪对产物进行了表征,并与其他模板聚合产物进行了比较.研究结果表明,PVS可作为HRP催化苯胺聚合的模板,合成的PVS/PANI的电导率为4.78×10-1S·cm-1,反应体系的pH值应控制在4.0～5.0,H2O2浓度以20 mmol·L-1为宜,PVS与苯胺的摩尔比应控制在1～1.5.     

固定化HRP/H2O2/ACAC酶促体系引发下降解淀粉接枝丙烯酰胺共聚物的合成与表征

以壳聚糖为载体、戊二醛为交联剂制备固定化辣根过氧化物酶（HRP）,采用固定化HRP/H₂O₂/乙酰丙酮（ACAC）酶促体系制备降解淀粉-丙烯酰胺接枝共聚物（St-g-PAM）,通过红外光谱、紫外光谱、核磁共振和电镜扫描等手段对接枝共聚产物进行了结构分析。结果表明,丙烯酰胺成功接枝在降解淀粉上。共聚物用做皮革复鞣剂进行了应用实验,应用结果表明复鞣后的革柔软、纤维分散好和选择填充性强。     

温敏聚合物及其水凝胶的研究进展

综述了温度敏感聚合物及其水凝胶最近几年的研究进展,讨论了该聚合物的组成、主链结构、分子量以及聚合方法对水凝胶和温敏聚合物的影响。随着聚合物的主链结构和侧链分子量的改变,聚合物的低临界溶解温度（LCST）可以在较宽的范围内进行调节。同时,活性聚合方法和普通自由基聚合方法也对水凝胶的相转变有着重要的影响。     

温度刺激响应型水溶性聚合物的研究进展

刺激响应型聚合物是材料学科研究的新领域,温度刺激响应型水溶性聚合物是刺激响应型聚合物的一个重要组成分。本文介绍了温度刺激响应型水溶性聚合物的响应机理和研究近况,并展望了未来的发展趋势。     

可逆CO_2/N_2响应型开关聚合物的合成及性能评价

以N-(3-二甲氨基丙基)甲基丙烯酰胺(DMAPMA)和丙烯酰胺(AM)为单体,以过硫酸铵和亚硫酸氢钠为引发剂进行自由基聚合,合成了一种CO_2/N_2开关响应型聚合物P(DMAPMA-AM)。通过单因素实验得出最佳合成条件为:n(AM)∶n(DMAPMA)=4∶1、单体总质量分数为25%、n[(NH_4)_2S_2O_8]∶n(NaHSO_3)=2∶3、引发剂加入量为单体总质量的0.2%、反应温度40℃、反应时间4 h。用FTIR、1HNMR对产物进行了结构表征,测量了质量分数为0.2%的聚合物水溶液在通入CO_2/N2前后的电导率、Zeta电位和平均粒径,并对其乳化性能进行了考察。结果表明:在通入CO_2后,溶液的电导率由12.6μs/cm上升到40.7μs/cm,Zeta电位由1.25 m V上升到10.11 m V,平均粒径由708.6 nm降低到137.1 nm,而向溶液改通N2后溶液的电导率降到14.2μs/cm,Zeta电位下降到1.96 m V,平均粒径上升到589.8 nm,表明P(DMAPMA-AM)具有可逆的CO_2/N2开关响应性能。扫描电镜测试发现,通入CO_2/N_2前后聚合物线团的尺寸以及疏水颗粒的数目发生了显著变化。CO_2/N2能将聚合产物存在的油水混合体系进行有效的破乳/乳化。     

两亲性聚异丙基丙烯酰胺的合成及其温敏性研究

通过自由基聚合和端酰胺键合的方法合成了一系列分子量不同的端胺基聚 N-异丙基丙烯酰胺 ( PNIPAm)及其含双十二和十四长链疏水烷基两亲性聚合物 ,通过聚合物水溶液的透光率随温度变化曲线的拐点确定其低临界溶解温度 ( LCST) ,并研究其影响因素。结果表明 ,两亲性 PNIPAm水溶液相转变温度不仅受聚合物结构如亲、疏水链长比的影响 ,而且与溶液浓度的也有较大关系。     

聚合物刷的合成与应用研究进展

聚合物刷由于在吸附、粘附、润滑以及润湿方面的显著特点,在许多方面都有重要的应用,显示了潜在而巨大的研究价值。本文综述了聚合物刷的基本理论、合成方法及应用的最新研究进展,并着重介绍了可控自由基聚合合成聚合物刷的方法。     

间苯二酚和3,5-二羟基苯甲酸共聚物的酶促合成与表征

在辣根过氧化物酶(HRP)/H2O2的催化体系下,间苯二酚(RSC)和3,5-二羟基苯甲酸(DBA)进行自由基聚合反应,制备了合成鞣剂。研究了单体配比以及反应各因素对共聚物性能的影响。结果表明,在间苯二酚和3,5-二羟基苯甲酸的摩尔配比为2∶1、反应温度为35℃、pH值为7.0、H2O2的滴加时间为90 min时,合成反应具有较高的产率。用红外光谱(FTIR)、核磁共振光谱(NMR)和凝胶渗透色谱(GPC)对聚合产物的结构和性能进行了表征。提出了RSC和DBA的自由基聚合反应机理。应用结果表明,聚合产物具有较好复鞣和助染性能。     

温敏性水凝胶的合成及表征

以羟丙基甲基纤维素与丙烯酰氯为原料,制备了羟丙基甲基纤维素丙烯酸酯;以偶氮二异丁腈为引发剂、以羟丙基甲基纤维素丙烯酸酯为大分子交联剂、N-异丙基丙烯酰胺为单体在N,N-二甲基甲酰胺中70℃下通过自由基聚合反应24 h,制备了温度敏感性水凝胶。用DSC对其相转变温度进行了表征,并测定了不同温度下达到溶胀平衡时水凝胶的溶胀比,进行了水凝胶的去溶胀动力学及干凝胶的再溶胀动力学研究。在聚合过程中,加入羟丙基甲基纤维素丙烯酸酯制得的水凝胶:相转变温度由30℃降为29℃;在10℃时溶胀比由29降为24.8;去溶胀速率加快,例如:该水凝胶在10 m in内失水率由56%降为16%,在30 m in内失水率由86%降为19%;并且减慢了凝胶的再溶胀速率。     

Synthesis and solution properties of temperature‐sensitive copolymers based on NIPAM

A kind of temperature‐sensitive water‐soluble polymers P(NIPAM‐HEMA‐AM) of N‐isopropylacrylamide (NIPAM), hydroxyethyl methacrylate (HEMA) and acrylamide (AM) were synthesized by free radical aqueous solution copolymerization. The polymers were characterized by Fourier transform infrared spectrum (FTIR) method. Solution properties, such as the influences of monomer ratios and additives on the low critical soluble temperature (LCST) of the polymer solutions as well as the viscosity‐temperature properties were studied. The results show that the polymer concentrations have no significant influence on the LCST of polymer solutions. The incorporation of HEMA units leads to a lower LCST, while AM units to a higher LCST. The additions of small molecules such as salt and surfactant also have significant effect on the LCST, the addition of NaCl decreases the LCST, while the addition of sodium dodecylbenzenesulfonate (SDBS) increases the LCST. The apparent viscosity of polymer solutions depends on temperature. The 1.5 wt % aqueous solutions of P(NIPAM‐HEMA‐AM) exhibits good thermo‐thickening behavior over 55°C, whereas the 0.8 wt % aqueous solutions do not show this behavior during the heating process. The aqueous solutions of P(NIPAM‐HEMA‐AM) are viscoelastic fluids, and the viscoelasticities mainly depend on temperature. Both the storage modulus (G') and loss modulus (G'') of 1.5 wt % polymer solutions increase with temperature. Over 55°C, G' exceeds G'', and the polymer solutions are elasticity‐dominated. In contrast, below 55°C, G'' is larger than G', and the polymer solutions are viscosity‐dominated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Simultaneous novel synthesis of conducting,nonconducting, and crosslinked polymers by microwave initiation

A novel synthesis of poly(dibromophenylene oxide) (P), conducting polymer (CP), and/or crosslinked polymer (CLP), and/or radical ion polymers (RIP) was achieved simultaneously from sodium 2,4,6‐tribromophenolate by microwave energy in a very short‐time interval. The synthesized polymers were characterized via elemental analysis, FTIR, ¹H NMR and ¹³C NMR, X‐ray diffraction spectroscopy, SEM, DSC, TGA, ESR, GPC, conductivity measurement, and light scattering. It was found that polymerization proceeds through both 1,2‐ and 1,4‐addition at equal rates. The effects of the energy and time on the % conversion and the polymer synthesis were investigated. The optimum condition for synthesis of P (the highest M_w, 2.97 × 10⁵ g/mol) and CP was 70 W for 5 min in 5 mL water and 100 W for 1 min in 0.5 mL water, having maximum values 23.6% and 27.2%, respectively. In addition, synthesis of CLP and RIP were achieved in 5 mL water at 350 W and 700 W at the end of 1 min, respectively. The direct synthesis of highly conducting polymer, with the conductivity of 1 S cm^?2 was achieved in the absence of applied doping process in a very short time sequence. P, CP, CLP, and RIP had fine granular, sponge‐like, dendrite, and coarse surface structures, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5427–5435, 2006     

Synthesis of novel zwitterionic polymers and their properties as filtrate reducer for water-based drilling fluid

The development of high-temperature and salt-resistant filtrate reducer is of great significance to the exploitation of deep and ultra-deep wells. In this study, Zwitterionic copolymer PANDS was synthesized by free radical polymerization using acrylamide (AM), N-vinylpyrrolidone (NVP), methacryloxyethyl trimethyl ammonium chloride (DMC) and sodium p-styrene sulfonate (SSS) as monomers. Through orthogonal test, the optimum synthesis conditions were determined as follows: n (AM): n (NVP): n (SSS): n (DMC) = 3.5:2:0.5:0.5, the reaction temperature is 50°C, the initiator concentration is 0.4 wt%. The structure and thermal stability of the copolymers were analyzed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (¹H-NMR) and thermogravimetry (TG). In addition, the filtration reduction performance of PANDS was evaluated according to the American Petroleum Institute (API) standard. The mechanism of reducing filtration loss was studied by laser particle size analysis, Zeta potential and scanning electron microscope analysis of mud cake. The results show that PANDS has good temperature resistance and good filtrate loss reduction. With the addition of 1.5%PANDS, the filtrate loss of drilling fluid is 8.7 mL after aging at 160°C for 16 h, and can resist 6 wt% NaCl and 1 wt% CaCl₂.     

Synthesis and characterization of well-defined comb-like branched polymers

Well-defined comb-like branched polymers having one branch in each repeating unit have been successfully synthesized by the coupling reaction of living polystyrene (PS) and polyisoprene (PI) anions with 1, 1-diphenylethenyl (DPE) groups along PS backbone prepared via atom transfer radical polymerization (ATRP) of 4-vinylbenzyloxy benzophenone (Sc) followed by Wittig reaction. The resulting comb-like branched polymers were characterized by IR, ¹H-NMR, gel permeation chromatography (GPC) and static light scattering (SLS) in detail. The effect of living chains and DPE group molar ratio on grafting efficiency was discussed. The results show the coupling reaction of living chains and DPE groups was highly effective, and the coupling efficiency can be controlled via the feed molar ratios of living chains and DPE groups. Moreover, the effect of molecular weights of backbone (PSe) and PSLi or PILi on grafting efficiency was also discussed. The results show that when excess living polymers were used, the almost quantitative grafting efficiency could be achieved. __________ Translated from Acta Polymerica Sinica (China), 2007, (3): 203–208 [译自: 高分子学报]     

聚乙烯己内酰胺的制备与表征

以乙烯己内酰胺单体(VCL)为原料,偶氮二异丁腈(AIBN)为引发剂,在水溶液中通过自由基聚合合成了聚乙烯己内酰胺. 考察了引发剂用量、溶剂用量、聚合反应时间和聚合反应温度对产物分子量和产率的影响,阐述了水溶液中自由基聚合的反应机理. 在VCL:AIBN:H2O=1:0.05:15(质量比),75℃下反应5 h的优化工艺条件下,产率能达到97%,并通过凝胶渗透色谱仪测定了聚合物的平均分子量. 以红外光谱和核磁共振对产品结构进行了表征,用分光光度计测定其临界溶解温度为32℃.     

乙烯基对苯二甲酸类甲壳型液晶高分子的形状记忆性能

通过自由基聚合合成了四种基于乙烯基对苯二甲酸类甲壳型液晶高分子（PBPCS,PMPCS,PDCHVT,PbiPCS）。TGA和DMA表征结果表明,这四种甲壳型液晶高分子均具有较好的热稳定性,其侧基末端基团刚性越大,相对应的片材在30～80℃温度区间刚性越大。形状记忆弯角回复测试表明：四种聚合物热压成型的片材都具有很好的形状记忆固定率,均接近100%。形状记忆回复效果与聚合物侧基的末端基团有关,侧基末端基团分别为对丁氧基苯基和环己基（对应聚合物分别为PBPCS和PDCHVT）时,片材显示出较好的形状记忆性能,形状记忆回复率分别为87%和100%。将PDCHVT通过熔融纺丝制成纤维,采用形状记忆循环DMA测试表征其形状记忆性能,结果表明PDCHVT纤维具有稳定的优异的形状记忆性能。     

温度敏感的固定化纤维素酶的合成及性能

具有低临界溶解温度（LCST）特性的聚合物聚（N-异丙基丙烯酰胺）与纤维素酶键联，对键联后的酶的各种性能进行了研究。实验结果表明，固定化的纤维素酶仍具有LCST特性，其稳定性也有所提高。     

Synthesis of azobenzene-functionalized star polymers via RAFT and their photoresponsive properties

Azobenzene-functionalized star polymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. First, azobenzene-functionalized linear macro chain transfer agents (Macro-CTA) were synthesized by RAFT polymerization of 6-[4-(4′-Methoxyphenylazo)phenoxy]hexylmethacrylate (MAz6Mc) using 2-(2′-cyanopropyl)dithiobenzoate (CPDB) as RAFT agent in presence of AIBN as initiator in anisole. Subsequently, star azopolymers were synthesized by polymerization of a difunctional azomonomer, BMA2Az, with resultant Macro-CTA in presence of AIBN as initiator in anisole. Star azopolymers were characterized by GPC and spectroscopic methods. Thermal properties of star azopolymers were determined by DSC and TMA. Molecular weight versus conversion and molecular weight versus polymerization time attest to living polymerization characteristics. Photoisomerization behaviors of star azopolymers were studied by irradiation of both UV and visible light. Surface relief gratings were inscribed on star azopolymer films upon exposure to an interference pattern of (RCP + RCP) Ar⁺ laser. A diffraction efficiency of 20% was obtained by exposure of Star-8 K(2.6 K) polymer film to an (RCP + RCP) Ar⁺ laser for about 30 min. Surface relief grating structures were investigated by AFM and polarized optical microscopy.     

离子液体在高分子合成中的应用

离子液体是一类新型的软功能材料或介质,具有优良的可设计性。它作为一种绿色溶剂,具有很多独特的物理化学性能。本文介绍了离子液体在自由基聚合反应、活性聚合反应、电化学聚合等高分子合成反应方面的应用。