含无规共聚组分的两嵌段聚合物A-b-(B-r-C)的合成以及自组装

通过原子转移自由基(ATRP)方法合成了其中一个嵌段是由2种单体无规共聚的两嵌段聚合物——聚丙烯酸肉桂酸乙酯-b-(聚苯乙烯-r-聚丙烯酸叔丁酯),(记为PCEA-b-(PtBA-r-PS)).讨论了聚合过程中影响分子量分布以及分子量控制的各种因素.通过氢核磁(1H-NMR)确定各嵌段的重复单元数分别为50,111,138.通过透射电镜(TEM)观察,研究了该嵌段聚合物在选择性溶剂1-氯癸烷以及环戊烷中的自组装行为,发现该嵌段聚合物在环己烷中直接分散可以形成有聚集倾向的短棒状或球形胶束,而在1-氯癸烷中直接分散得到的胶束,在膜表面随着1-氯癸烷溶剂的缓慢挥发可以组装得到具有规则微纳结构的相互连接的柱状胶束.     

多臂聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯嵌段共聚物的合成及性能研究

采用电子转移再生催化剂原子转移自由基聚合(ARGET ATRP)制备了端羟基聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯嵌段共聚物(HO-PBA-b-PMMA),在此基础上,与六亚甲基二异氰酸酯三聚体(N3390)反应,合成了多臂聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯嵌段共聚物.通过凝胶渗透色谱(GPC)、核磁共振仪(1H-NMR)、傅里叶变换红外光谱计(FTIR)对聚合物的结构进行了表征,利用原子力显微镜(AFM)观察了其形貌,采用动态热机械分析仪(DMA)和万能拉伸机研究了聚合物的热性能、力学性能及多臂嵌段共聚物对PMMA的增韧性能.结果表明:成功制备了端羟基聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯,以及多臂聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯嵌段共聚物.在异氰酸酯基/羟基(NCO/OH)摩尔比为1.2/1时,制得的多臂嵌段共聚物相对分子质量最大,Mark-Houwink参数α值最小,表明此时三臂嵌段共聚物最多.多臂嵌段聚合物的拉伸强度和断裂伸长率比线型聚合物均有明显提高,且在NCO/OH摩尔比为1.2/1时达到最大,分别为7.6 MPa和73%.多臂嵌段聚合物具有更高的玻璃化转变温度(Tg).通过原子力显微镜(AFM)表明,多臂聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯嵌段共聚物形成了以聚丙烯酸丁酯链段为核,聚甲基丙烯酸甲酯为壳的核壳结构.具有核壳结构的多臂聚丙烯酸丁酯-b-聚甲基丙烯酸甲酯嵌段共聚物对聚甲基丙烯酸甲酯有明显的增韧作用.     

含氟聚甲基丙烯酸酯/聚异丁烯嵌段共聚物的成膜性质研究

利用氧负离子聚合方法制备含氟聚异丁烯三嵌段共聚物,聚异丁烯-b-聚甲基丙烯酸-2-(N,N-二甲氨基)乙酯-b-聚甲基丙烯酸-(2,2,3,3,4,4,5,5-八氟)戊酯(PIB-b-PDMAEMA-b-POFPMA),对PIB60-bPDMAEMA63-b-POFPMA11的物理化学性质和成膜性能进行了研究.利用1H-NMR和GPC表征了聚合物的化学结构、分子量及分子量分布;通过TGA和DSC测试了聚合物的热分解温度与玻璃化转变温度(Tg).实验结果表明,PIB60以及PDMAEMA63的Tg分别为-61℃和5℃,PIB60-b-PDMAEMA63在-4℃左右存在一个Tg,而PIB60-b-PDMAEMA63-b-POFPMA11不仅在-4℃存在玻璃化转变,而且在26℃存在另一个玻璃化转变,对应于POFPMA嵌段的Tg.将聚合物制成薄膜,通过接触角测试发现聚合物薄膜具有一定的疏水疏油性质.根据Owens-Wendt公式计算了聚合物薄膜的自由能、分散能和极性能.利用原子力显微镜(AFM)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和X射线衍射分析(XRD)研究了聚合物中含氟嵌段向薄膜表面迁移富集和堆积结构,结果显示,在退火之后,含氟嵌段向薄膜的表面迁移、富集,并在表面排列形成双层堆积结构.     

结构可控的聚合物长短刷接枝纳米粒子

通过RAFT聚合制备了一系列窄分子量分布的聚(γ-甲基丙烯酰氧基丙基三乙氧基硅烷)(PTEPM)-b-聚甲基丙烯酸甲酯(PMMA)嵌段共聚物和PTEPM、PMMA低聚物.将具有不同PMMA分子量的2种PTEPM-b-PMMA共聚物与低聚物PMMA或PTEPM进行共组装(微相分离),形成片、柱、球等不同PTEPM相区结构.采用盐酸气氛处理,PTEPM相区水解交联形成倍半硅氧烷SiO1.5内核,分离纯化得到聚合物长短刷接枝纳米粒子.使用这种相分离-交联-分散制备方法,调节嵌段共聚物分子结构和三组分比例,可实现聚合物接枝纳米粒子内核形状和尺寸、接枝密度、长短刷比例、长刷长度的精确调控.这些纳米粒子是研究聚合物纳米复合材料结构-性能关系的理想模型体系.     

利用MALDI-TOF质谱技术研究MPEG-b-PCL两嵌段共聚物的嵌段长度及嵌段分布

利用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)结合源后分解(PSD)技术对甲氧基封端的聚乙二醇-b-聚己内酯(MPEG-b-PCL)两嵌段共聚物进行了结构分析. 根据得到的MALDI-TOF MS谱图和PSD碎片信息清晰地确定了嵌段共聚物的嵌段长度和嵌段分布. 结果表明, 采用MALDI-TOF MS结合PSD技术研究这类嵌段共聚物链结构非常有效. 这为更好地认识和应用这类嵌段共聚物提供了重要的依据, 同时也建立了分析这类嵌段共聚物的方法.     

树枝状嵌段聚合物D-PCL-b-PS在不对称末端受限条件下的结晶行为

研究了树枝状嵌段聚合物聚(ε-b-己内酯)-b-聚苯乙烯(D-PCL-b-PS)的分子结构对PCL链段受限结晶行为的影响.首先,通过活性正离子开环聚合(ROP)合成了树枝状的嵌段聚合物D-PCL.在此基础上用原子转移自由基聚合(ATRP)的方法,合成了树枝状的嵌段聚合物D-PCL-b-PS,在结晶的PCL链段的两个末端...     

含强推拉电子型偶氮苯的嵌段共聚物合成与自组装研究

利用原子转移自由基聚合(ATRP)和前体聚合物重氮偶合反应相结合的方法,制备了一种新型含强推拉电子型偶氮苯的嵌段共聚物PEG-b-P6CNAzo.首先使用大分子引发剂PEGBr引发单体甲基丙烯酸6(N-甲基苯胺基)己酯进行ATRP聚合,得到作为前体聚合物的两嵌段共聚物PEG-b-P6MA,然后再与4-氰基苯胺的重氮盐进行重氮偶合反应得到目标产物PEG-b-P6CNAzo.利用GPC1、H-NMR、UV-Vis等手段对制得的聚合物进行了详细的表征.1H-NMR分析结果表明PEG-b-P6MA的聚合度为122-b-13,重氮偶合反应转化率接近100%.GPC结果表明PEG-b-P6MA与PEG-b-P6CNAzo均具有较窄的分子量分布.向浓度为0.2 g/L的PEG-b-P6CNAzo四氢呋喃溶液中以0.5 mL/h速率加水,该嵌段共聚物可以形成直径约11 nm的棒状胶束.     

极性单体锂系阴离子嵌段共聚物的合成与表征

以酚锂作为副反应抑制剂, 以正丁基锂或1,1-二苯基乙烯盖帽的正丁基锂为引发剂, 通过顺次添加单体的方法, 合成了结构明确的聚异戊二烯-b-聚甲基丙烯酸甲酯(PI-b-PMMA)和聚甲基丙烯酸正丁酯-b-聚甲基丙烯酸甲酯(PBMA-b-PMMA)2种嵌段聚合物. 嵌段聚合反应中甲基丙烯酸甲酯(MMA)的转化率均高于90%, 通过核磁图谱计算的链节摩尔比与理论设计值吻合. PI-b-PMMA和PBMA-b-PMMA的分子量分别达到4×10⁴和1.6×10⁴. 在环己烷中, 通过顺次添加单体的方法, 合成了结构明确的聚苯乙烯-b-聚异戊二烯-b-聚甲基丙烯酸甲酯(PS-b-PI-b-PMMA)三嵌段共聚物, 各单体的转化率均达到100%, 并且产物中的链节摩尔比和理论设计值一致, 最终产物的分子量达到7.4×10⁴, 分子量分布仅为1.28, 为极性三嵌段热塑性弹性体以及有机玻璃透明增韧剂的工业化奠定了基础.     

窄分布两亲性嵌段共聚物的合成及其胶束化行为研究

利用原子转移自由基聚合合成了具有两亲性的嵌段聚合物聚苯乙烯-b-聚丙烯酸(PS-b-PAA),用FTIR,¹H NMR,SEC对其进行了表征,并利用荧光探针技术研究了其在水溶液中的胶束化行为.进一步的研究表明,PS-b-PAA胶束可对水中存在的多环芳香化合物芘有效地吸收并进而分离和回收.     

含有机硅三元多嵌段共聚物的研究

以双酚Ａ聚砜（ＰＳＦ）为硬段、聚对羟基苯乙烯（ＰＨＳ）为半硬段、聚二甲基硅氧烷（ＰＤＭＳ）为软段合成了三元多嵌段共聚物，并对其动态力学和抗张性能比较研究，结果表明该三元多嵌段共聚物为多相结构；在引入半硬段ＰＨＳ后两相间的界面相增宽，粘接力增大，其强度和模量高且稳定，使含有机硅高分子材料强度低的弱点得以改善，扭（ＴＢＡ）结果显示，这种三元多嵌段共聚物具有多重转变，且在－２０℃至５０℃间有两个较大的几     

SYNTHESIS AND CHARACTERIZATION OF BLOCK POLYMER OF ALTERNATING COPOLYMERS

Block polymer of alternating copolymers, poly[(ST-a-MA)-b(IP-a-MMA)-b-(ST-a-MA)](I), has been synthesized in the presence of AlEt_(1.5)Cl_(1.5),by using Mn_2(CO)_(10)/CBr_4. initiation system.The GPC results indicate that there is no unreacted prepolymer in I purified by precipitation andfractionation. The study of NMR shows that every block of polymer I has alternating structure. The dynamicmechanical properties of I measured by torsional braid method indicate that the polymer has two T_g s,being 38 and 75℃, respectively. The transmission electron micrographs of I show they have two phasestructure and the domain size increases with increasing molecular weight of hard block.     

N-苯基马来酰亚胺与环己烯共聚物的制备和表征

Ｎ苯基马来酰亚胺（ＰＨＭＩ）是一种很有应用价值的共聚单体,它能赋予共聚物很好的耐热性．有关ＰＨＭＩ与甲基丙烯酸甲酯、苯乙烯及乙烯基醚的二元共聚合反应已有文献报道［１～３］．而有关ＰＨＭＩ与环烯烃特别是环己烯的共聚合研究除我们所做的工作外［４］,报道甚少．作者研究了ＰＨＭＩ与环己烯在溶液中的二元共聚合反应,并对所得的共聚物进行了表征．１　原料ＰＨＭＩ,自制,ｍ．ｐ．８８－７℃;元素分析Ｃ,６９－３３;Ｈ,４－０７;Ｎ,８－１０;理论值Ｃ,６９－３６;Ｈ,４－０７;Ｎ,８－０９,１ＨＮＭＲ（δ）…     

丁二烯与甲基丙烯酸甲酯交替共聚物及其嵌段聚合物的13C-NMR研究

本文研究了丁二烯(BD)与甲基丙烯酸甲酯(MMA)交替共聚物的¹³C-NMR谱,结果表明,交替度达99.2%。其中,反式1,4-,顺式1,4-和1,2-BD分别约占97.6%,1.3%和1.1%。对交替共聚物的嵌段聚合物Poly[(ST-a-MA)-b-(BD-a-MMA)-b-(ST-a-MA)]的¹³C-NMR谱研究,证明其为嵌段结构,每一段都是交替共聚物。     

完全交替结构乙烯-丙烯共聚物的制备与表征

对顺-1,4含量为100%的高顺式聚异戊二烯(HCPI)进行加氢反应,得到了序列结构高度规整的乙烯-丙烯交替共聚物(alt-EP).所用的HCPI有适当的分子量(Mn=41×104)和极窄的分子量分布(Mw/Mn=1.02).HCPI的加氢反应以环烷酸镍和三异丁基铝为催化剂,在60℃和4.0MPa氢压的条件下反应3h,加氢产物的加氢度为100%.GPC测试结果显示所得乙烯-丙烯交替共聚物保持了窄分布的特点,表明HCPI加氢后未发生交联和降解反应;NMR,FTIR和广角X射线衍射测试结果表明此乙烯-丙烯交替共聚物具有高度规整的序列结构,为完全交替结构的乙烯-丙烯共聚物.并通过TGA和DSC对乙烯-丙烯交替共聚物的热性能进行了表征.     

Synthesis of Sequence-specific Poly(ester-carbonate) Copolymers via Chemoselective Terpolymerization Controlled by the Stoichiometric Ratio of Phosphazene/Triethylborane

Chemoselective terpolymerization can produce polymer materials with diverse compositions and sequential structures, and thus have attracted considerable attention in the field of polymer synthesis. However, the intrinsic complexity of three-component system also brings great chanllenge, in regard to the reactivity and selectivity of different monomers. Herein, we report the terpolymerization of CO₂/epoxide/anhydride by a binary organocatalytic C₃N₃-Py-P₃/TEB (triethylborane) system. Both the activity and chemoselectivity were highly dependent upon the molar ratio of C₃N₃-Py-P₃ to TEB, and sequence-controlled poly(ester-carbonate) copolymers were readily synthesized through one-pot/one-step methodology by tuning the stoichiometric ratio of phosphazene/TEB. In particular, C₃N₃-Py-P₃/TEB with a molar ratio of 1/0.5 exhibited an unprecedentedly high chemoselectivity for ring-opening alternating copolymerization (ROAC) of cyclohexene oxide (CHO) and phthalic anhydride (PA) first and then ROAC of CO₂/CHO. Thus, well-defined triblock polycarbonate-b-polyester-b-polycarbonate copolymers can be produced from the mixture of CO₂, CHO and PA using a bifunctional initiator. With C₃N₃-Py-P₃/TEB=1/1, tapered copolymers were obtained, while random copolymers with high content of polycarbonate (PC) were synthesized with further increasing the amount of TEB. The mechanism of the unexpected chemoselectivity was further investigated by DFT calculations.     

A Transformable and Bulky Methacrylate Monomer That Enables the Synthesis of an MMA-nBA Alternating Copolymer: Sequence-Dependent Self-Healing Properties

In this study, we designed a methacrylate molecule with an alkyl-substituted trichloro salicylic acid pendant as a transformable bulky monomer to enable the synthesis of an alternating copolymer of methyl methacrylate (MMA) and n-butyl acrylate (nBA). The adamantyl-substituted methacrylate monomer ( 1-Ad ) showed very low homopolymerization propensity in radical polymerizations, but afforded the alternating copolymer with nBA via copolymerization. The 1-Ad units in the resultant copolymer were quantitatively and selectively transformed into MMA via transesterification with methanol to yield the alternating copolymer of MMA and nBA. Its alternating sequence was clearly demonstrated by a structural analysis via ¹³C NMR spectroscopy as well as the low reactivity ratios for the 1-Ad and nBA pair. Finally, we verified the superior self-healing ability of the alternating copolymer compared to that of the corresponding 1 : 1 statistical copolymer.     

NON-LINEAR LEAST SQUARE CURVE FITTING OF COPOLYMERIZATION MODELS TO THE ALTERNATING TRIAD FRACTION OF COPOLYMERS OF STYRENE AND CITRACONIC ANHYDRIDE,AND COPOLYMERS OF STYRENE AND MALEIC ANHYDRIDE PREPARED IN N,N-DIMETHYLFORMAMIDE

Copolymers of styrene (ST) and citraconic anhydride (α-methylmaleic anhydride) (CA) were prepared in a very polar solvent, N,N-dimethylformamide (DMF), at 50.0°C with AIBN. The monomer unit triad fractions were determined by ¹³C NMR in acetone-d ₆ solution. Non linear least square (NLLS) curve fitting was performed for the copolymerization models of the terminal model, the penultimate unit effect model, the complex participation model, the complex dissociation model, and the so-called comppen model. The theoretical equations for the ST-centered alternating triad mole fraction were fitted by NLLS minimization routine to the triad fraction data of the ST-CA copolymers and that of the ST-maleic anhydride (MA) copolymers prepared in identical polymerization conditions. It was found that for rigidly alternating copolymers of ST-MA, the difference among the copolymerization models disappeared and all models merged together. The difference among the copolymerization models were somewhat more apparent for less alternating copolymers of ST-CA copolymers. The sum of squares values indicated that the copolymerization models, which involved some complex participation, fit the data better with the comppen model. This was a combination of a complex participation and penultimate unit effects, which performed best.     

电化学合成吡咯与己内酰胺导电共聚物

采用恒电位方法实现了吡咯与己内酰胺在导电玻璃电极上的直接电化学共聚,聚合反应在含有0.1mol/L吡咯和1.5 mol/L己内酰胺的硝基甲烷电解质溶液中进行,外加电位控制在1.2 V以上.聚合产物中聚吡咯与聚己内酰胺链段的组成可通过调节合成电位加以控制.共聚物的形貌、结构与性质采用扫描电子显微镜、热重分析、红外光谱等手...     

丙烯-马来酸哌啶酯共聚物的合成与表征

<正> 以2,2,6,6-四甲基哌啶为母体的衍生物作为受阻胺光稳定剂,其效率约为镍-螯合物光稳定剂的2—6倍,已引起人们的注意,但是小分子受阻胺易于挥发,从而使其光稳定作用较差。为了克服上述缺点,使受阻胺稳定剂高分子化是近年来展的趋势,本文合成了含有“丙烯”单元的高分子受阻胺光稳定剂——丙烯-马来酸哌啶酯共聚物,力求改进它与丙烯的相容性,提高光稳定效率,本文还对共聚物进行表征。