聚(苯乙烯-b-2-甲基-2-（口恶）唑啉)嵌段共聚物的合成

核磁、离子色谱等测试方法证明 ,以烯丙基型卤代烷烃为引发剂引发的过渡金属催化的活性自由基聚合 ,所得聚合物的端基为卤素[13].由于Ｃ—Ｘ(Ｘ =Ｃｌ,Ｂｒ)键容易断裂 ,因此卤素端基的存在会影响聚合产物的热稳定性 .但由于Ｃ—Ｘ键易于进行各种反应 ,含卤素端基的聚合物可以作为大分子引发剂用于引发其它合适单体反应 ,从而使卤素端基转化为其它基团 ,或合成新型结构的共聚物 .环状单体 2 甲基 2 唑啉 (Ｍｅ ＯＸＺ)亲核性较强 ,可以直接由烯丙基型卤代物引发剂引发活性开环聚合[4 6 ],因此可望以含卤端基的活性聚合产物作为Ｍｅ ＯＸ…     

活性正离子聚合及原位制备聚醋酸乙烯酯-g-聚四氢呋喃共聚物/纳米银复合材料

通过将烯丙基溴/高氯酸银引发体系引发四氢呋喃活性正离子开环聚合与"grafting onto"合成方法相结合,原位制备了不同接枝密度和接枝链长度的新型聚醋酸乙烯酯-g-聚四氢呋喃接枝共聚物(PVAc-g-PTHF)及其与纳米银(Ag)的复合材料.采用傅里叶变换红外光谱(FTIR)、核磁共振波谱(1H-NMR)和多角度激光光散射-黏度-凝胶渗透色谱仪(MALLS-VIS-GPC)分别表征了该接枝共聚物的化学结构、共聚组成、分子量、分子量分布、接枝支链数目及支化度,采用原子力显微镜(AFM)、示差扫描量热分析(DSC)、偏光显微镜(POM)研究了接枝共聚物中接枝支链数目及支链长度对其微观形态、单端受限链段结晶行为的影响,并探讨了该纳米复合材料的抗菌性能.结果表明:所制备的不同支链数目和支链长度的PVAc-g-PTHF/Ag纳米复合材料,均表现出良好的抗菌性能;接枝共聚物PVAc-g-PTHF的重均分子量可达4.52×10~5,分子分子量较窄(M_w/M_n~1.8),支化因子可达0.19.接枝共聚物PVAc-g-PTHF可形成明显的相分离结构,其微观形态与接枝支链数目有关;相比相同分子量的双端不受限的PTHF链,PVAc-g-PTHF接枝共聚物中单端受限PTHF支链的结晶速率明显降低;在确定接枝支链数目的情况下,随着支链中PTHF链段长度增加,其结晶逐渐增强,结晶熔融温度及熔融焓均稍有增加.     

Polycaprolactone–poly(ethylene glycol) block copolymer,I: synthesis and degradability in vitro

A new type of biodegradable polymer material, poly(caprolactone)–poly(ethylene glycol) block copolymer (PCL-b-PEG), was synthesized by means of direct copolycondensation of ε-caprolactone with poly(ethylene glycol) in the presence of a Ti(OBu)₄ catalyst. The degradability of the polycaprolactone was improved by introducing a PEG component into it. The degradation of PCL-b-PEG copolymer increase with a decreasing crystallinity of the copolymer, and can be controlled by adjusting the component ratio of the copolymer.     

Y-shaped block copolymers of poly(ethylene glycol) and poly(N-isopropylacrylamide) synthesized by ATRP

Novel Y-shaped block copolymers of poly(ethylene glycol) and poly(N-isopropylacrylamide),PEG-b-(PNIPAM)_2,were successfully synthesized through atom transfer radical polymerization(ATRP).A difunctional macroinitiator was prepared by esterification of 2,2-dichloroacetyl chloride with poly(ethylene glycol) monomethyl ether(PEG).The copolymers were obtained via the ATRP of N-isopropylacrylamide(NIPAM) at 30℃with CuCl/Me_6TREN as a catalyst system and DMF/H_2O(v/v = 3:1) mixture as solvent.The resulting copo...     

Synthesis of poly(vinyl acetate)-b-poly(dimethylsiloxane)-b-poly(vinyl acetate) triblock copolymers by iodine transfer polymerization

Iodine transfer polymerization of vinyl acetate in bulk, initiated by α,α′-azobisisobutyronitrile at 80 °C, has been successfully performed in the presence of an α,ω-diiodo-poly(dimethylsiloxane) macrotransfer agent. The formation of a triblock copolymer PVAc-b-PDMS-b-PVAc has been proved by ¹H NMR and size exclusion chromatography analyses. The analysis of the chain-ends has been performed using ¹H NMR. It was found that a large amount of inverse chain-ends is present at the end of the polymerization. Moreover, the formation of several other side products by degradation of the functional chain-ends has been evidenced.     

Poly(2-oxazoline)-Containing Triblock Copolymers: Synthesis and Applications

This review focuses on poly(2-oxazoline) containing triblock copolymers and their applications. A detailed overview of the synthetic techniques is provided. Triblock copolymers solely based on poly(2-oxazoline)s can be synthesized by sequential monomer addition utilizing mono- as well as bifunctional initiators for the cationic ring-opening polymerization of 2-oxazolines. Crossover and coupling techniques enable access to triblock copolymers comprising, e.g., polyesters, poly(dimethylsiloxane)s, or polyacrylates in combination with poly(2-oxazoline) based segments. Besides systematic studies to develop structure property relationships, these polymers have been applied, e.g., in drug delivery, as (functionalized) vesicles, in segmented networks or as nanoreactors.     

三臂支化PLLA-PDLA嵌段共聚物的合成及立构复合结晶行为

以三羟甲基乙烷为起始剂, 开环聚合L-丙交酯(LLA), 合成三臂支化左旋聚乳酸(PLLA)预聚物. 采用端基活化技术对预聚物进行端羟基活化, 再与D-丙交酯(DLA)进行开环聚合, 合成了不同分子量的三臂支化左旋聚乳酸-右旋聚乳酸(PLLA-PDLA)嵌段共聚物. 采用核磁共振谱和凝胶渗透色谱等对样品的结构和分子量进行测试, 结果表明,合成的嵌段共聚物链结构具有链段立构规整度和高分子量的特点; 通过调节DLA单体与PLLA预聚物的投料比, 可实现对PLLA-PDLA嵌段共聚物的序列结构调控. 差示扫描量热仪和广角X 射线衍射结果表明, 三臂支化PLLA-PDLA嵌段共聚物的异构体分子间生成立构复合晶体, 其熔点高于200℃; 共聚物的嵌段序列结构对材料的凝聚态转变行为有很大的影响.     

Synthesis and MALDI-TOF-MS of PS-PMA and PMA-PS block copolymers

The synthesis of well-defined block copolymers from styrene and methyl acrylate via ATRP is discussed in this contribution. Kinetic studies on these block copolymerizations as well as characterization studies were performed to investigate the monomer composition in the respective PS and PMA blocks. MALDI-TOF-MS was performed to clarify the exact number of repeating units of each block and the total number of units in the block copolymer. Block copolymers up to 22 kDa could be analyzed by MALDI-TOF-MS, whereby polymers with PMA as first block showed a large second distribution corresponding to PMA homopolymers. However, SEC demonstrated that only a small amount of homopolymer was present indicating that care needs to be taken with interpreting MALDI-TOF-MS data, which is a qualitative rather than a quantitative technique.     

含聚氧乙烯链段的两亲嵌段共聚物及接枝共聚物的分子设计,合成及性能

论述了由聚烯链段与聚苯乙烯或聚（甲基）丙烯酸酯链段组成的各种嵌段或接枝共聚物（包括二嵌段、两种三嵌段、星型嵌段、多嵌段、二种规整接枝共聚物等）的分子设计及合成,并总结了其两亲性质、络合碱金属离子性及微观相分离等特性。     

ABA型聚L-丙氨酸-聚乙二醇嵌段共聚物的合成及其表征

利用L-α-丙氨酸和三聚光气反应制备了N-羧基-α-丙氨酸-环内酸酐(NCA).以聚乙二醇(PEG)为原料.制备了端氨基聚乙二醇(PEG-NH₂),并以此作为引发剂,引发NCA开环聚合.合成了不同组成和分子量的聚L-丙氨酸-聚乙二醇(PLAA-PEG-PLAA)嵌段共聚物.利用IR、¹H NMR、DSC、WAXD、CD等方法对共聚物结构进行了表征.结果表明,PEG-NH₂引发NCA开环聚合得到的是嵌段共聚物,通过¹H NMR谱得到共聚物组成及数均分子量;引入PEG的结果使聚L-丙氨酸的亲水性有所改善;CD测诚结果表明共聚物在水溶液中主链主要以α-螺旋构象存在.     

Effects of polystyrene-b-poly(aminomethyl styrene)s as stabilizers on dispersion polymerization of styrene in alcoholic media

The effects of polystyrene-b-poly(aminomethyl styrene) (PS_n-b-PAMS_m) stabilizers on the particle size (D_n) and size distribution (PSD) in dispersion polymerization of styrene were investigated. The block copolymers, PS_n-b-PAMS_m, were prepared as follows: (i) atom transfer radical polymerization (ATRP) of styrene (PS-Br), (ii) ATRP of vinylbenzylphthalimide with the PS-Br (PS-b-PVBP), and (iii) treatment of the PS-b-PVBP with hydrazine. When the dispersion polymerization of styrene proceeded at 60 °C in ethanol with PS₁₉-b-PAMS₁₃₀ stabilizer, spherical polystyrene particles with D_n=0.91 μm (PSD = 1.01) were obtained. The particle size was strongly affected by the copolymer composition. With an increase in PAMS block length from m=54 to 100 in PS₁₇-b-PAMS_m, particle diameter became smaller from 1.55 to 0.91 μm. On the other hand, an increase in the length from m=20 to 82 in PS₃₄-b-PAMS_ms caused an increase in particle size from 0.35 to 0.70 μm. Titration of the particles suggests that 14–81% of stabilizers used in the polymerization system were attached on the polystyrene particle surfaces, depending on the composition of the block copolymers. Thus, for the dispersion polymerization of styrene, PS_n-b-PAMS_m block copolymers have both functions as a stabilizer during polymerization and surface-modification sites of polystyrene particles.     

基团转移聚合合成PMMA—PEA—PAN嵌段共聚物的研究

丙烯酸系橡胶的综合性能仅次于氟橡胶,成本较低,若制成可重复加工的热塑性弹性体则更有价值。前人曾用阴离子聚合法进行过合成试验,均因副反应太多等原因而未能获得满意的结果。基团转移聚合(GTP)是八十年代建立的合成高分子新方法,在室温下进行“活性聚合”是其重要特征。本文利用GTP方法、单官能团引发剂,仅通过适当控制加料次序和时机就合成了软段居中的三元共聚物,为合成全丙烯酸系热塑弹性体奠定了基础。     

聚天冬氨酸/3,5-二氨基苯甲酸的合成及缓蚀阻垢性能

通过氨基开环的方法合成了聚天冬氨酸/3,5-二氨基苯甲酸接枝共聚物(PASP/3,5-DMBA),采用静态阻垢、动态腐蚀等方法考察了该共聚物的阻垢和缓蚀性能。结果表明,3,5-二氨基苯甲酸的引入可有效改善聚天冬氨酸(PASP)的阻垢与缓蚀性能,尤其在较低的浓度下对CaSO_4和Ca_3(PO_4)_2的阻垢性能有明显的提高。当PASP/3,5-DMBA药剂用量分别为1.25mg/L、6mg/L时,其对CaCO_3、CaSO_4的阻垢效率接近100%。当用量为18mg/L时,对Ca_3(PO_4)2的阻垢效率可达75%。通过扫描电镜(SEM)观察发现,加入PASP/3,5-DMBA后钙垢晶体结构发生了畸变,呈分散开花状。     

Synthesis and Characterization of Chitosan-g-poly- （D, L-lactic acid） Copolymer

Biodegradable chitosan-g-poly (D, L-lactic acid) copolymers were prepared via two methods. (1) The lactide was grafted onto hydroxyl groups of chitosan by using macromolecular initiator sodium of trimethylsilyl-chitosan, (2) poly (D,L-lactic acid)(PLA) with low molecular weight can be linked to the amino group by coupling activated PLA to trimethylsilyl-chitosan. Two graft copolymers had hydrophilic-hydrophobic character and can be applied as carriers for drug delivery.     

阴离子聚合法合成PMMA-b-PMTFPS嵌段共聚物

以含缩醛官能团的有机锂为引发剂, 将甲基丙烯酸甲酯(MMA)与含氟硅氧烷单体1,3,5-三甲基-1,3,5-三(3',3',3'-三氟丙基)环三硅氧烷(F3)阴离子嵌段共聚, 获得了窄分子量分布的聚甲基丙烯酸甲酯-b-聚[甲基(3,3,3-三氟丙基)硅氧烷](PMMA-b-PMTFPS)嵌段共聚物, 并用GPC, 1H NMR, FTIR和DSC对嵌段共聚物进行了表征. 研究结果表明, 在THF中利用PMMA-OLi对F3进行阴离子开环聚合时, 单体F3浓度的选择对提高嵌段共聚物产率至关重要.     

Oxidative and photooxidative degradation of poly(acrylic acid)

The oxidative degradation of poly(acrylic acid) (PAA), a water soluble polymer, was studied at various temperatures with different concentrations of persulfates, potassium persulfate (KPS), ammonium persulfate (APS) and sodium persulfate (SPS). The photodegradation of PAA was also examined with APS as oxidizer. The degraded samples were analyzed for the time evolution of molecular weight distribution by gel permeation chromatography. A theoretical model based on the continuous distribution kinetics was developed that accounted for the polymer degradation and the dissociation of persulfate. The rate coefficients for the oxidative and photooxidative degradation of PAA were determined from the parametric fit of the model with experimental data. The rate of degradation increased with increasing amount of persulfate in both oxidative and photooxidative degradation. The rate of degradation also increased with increasing temperature in the case of oxidative degradation.     

SYNTHESIS OF AN AMPHIPHILIC PPESK-g-P(PEGMA) GRAFT COPOLYMER VIA ATRP AND ITS USE IN BLEND MODIFICATION OF PPESK MEMBRANES

Preparation of an amphiphilic graft copolymer having poly(phthalazinone ether sulfone ketone)(PPESK) as main chains was carried out by atom transfer radical polymerization(ATRP).The precursor,chloromethylated PPESK (CMPPESK),was prepared by using chioromethylether as chloromethylation agent.Then,poly(ethylene glycol) methyl ether methacrylate(PEGMA) was used as monomer to synthesize PPESK-g-P(PEGMA) by ATRP method under the catalysis of a cuprous chloride/2,2'-bipyridyl system.PPESK/PPESK-g-P(PEGMA) blen...     

苯胺四聚体-PEG两亲性嵌段共聚物的合成、表征及自组装行为

以二环己基碳二亚胺（DCC）为缩合剂与聚乙二醇单甲基醚（mPEG）反应的产物再与苯胺四聚体（AT）反应得到了两嵌段共聚物. 采用1H-NMR和FTIR分析方法确认了共聚物的结构,UV-Vis及CV的测试结果表明该共聚物具有良好的电活性特征. 用扫描电镜与光散射的方法对粒径大小进行了测量,共聚物在水溶液中可形成直径125 nm左右的均匀球形组装体,并通过透射电镜确定了组装体的实心结构. 当嵌段共聚物处于中间氧化态时,组装体的尺寸会随着溶液pH值的不同而变化. 对组装体的形成及pH敏感性的可能机理进行了讨论.     

Synthesis of poly[arylene ether sulfone-b-vinylidene fluoride] block copolymers

A series of α,ω-dihydroxy polyarylene sulfones (PAES) were synthesized comprising bisphenol A (PAES1, M_n=1800, 4900, and 9500 daltons), 4,4^′-biphenol (PAES2, M_n=4100 daltons), and hexafluorobisphenol A (PAES3, M_n=3300 daltons). These were reacted with α,ω-dibromo poly(vinylidene fluoride) (PVDF, M_n=1200 daltons) prepared by telomerization, to yield block copolymers possessing rigid and flexible segments. Block copolymers were characterized by FTIR, NMR, GPC, DSC, TGA and TEM. In several cases the block copolymers exhibited distinct thermal transitions, i.e. T_m and T_g for PVDF and PAES segments, respectively. Where observable, T_g of PAES domains in the block copolymers occurred at a temperature lower than the corresponding PAES homopolymer due to the flexible nature of the surrounding PVDF domains. Block copolymers exhibited a similar thermal stability to the corresponding PAES homopolymers but higher stability than the PVDF homopolymer, and much higher still than α,ω-dibromo PVDF. TEM analyses indicate that phase separation of PAES and PVDF domains occurs on the nanometer scale.     

ATRP大分子引发剂的合成及应用

原子转移自由基聚合(ATRP)是一种新型的可控/活性聚合技术,现已广泛应用于聚合物分子结构设计、无机材料表面修饰、蛋白质检测以及生物大分子的分离和杀菌防污等.在此类反应过程中涉及的三大要素:单体、引发体系(引发剂、催化剂、配位剂)及反应介质,其中核心要素为ATRP引发剂,其结构与性质是ATRP反应成败的决定因素之一.本文在综述了小分子引发剂的种类与性质及ATRP的反应机理的基础上,着重综述了近年来官能团反应法、偶联反应法及自由基聚合法制备ATRP大分子引发剂的最新进展.同时还综述了大分子引发剂通过ATRP反应在聚合物结构设计中的应用,以及对无机材料和生物材料的表面修饰的最新进展,最后对ATRP引发体系的未来发展与应用进行了展望.