紫外光固化超支化聚酯的合成及性能

以季戊四醇为核,2,2-羟甲基丙酸为臂,采用熔融缩聚法合成并表征了末端含大量羟基的超支化聚酯,其支化度高,黏度低,具有良好的热稳定性.以甲基丙烯酸酐改性超支化聚酯,得到链末端含有C=C的超支化甲基丙烯酸酯,在最佳反应条件下改性反应的转化率可达89%以上.改性后的超支化聚酯表现出更低的黏度,热失重曲线呈现为两段,玻璃态转...     

氢键作用对端羟基超支化聚酯熔体流变性能的影响

以三羟甲基丙烷(TMP)为核,二羟甲基丙酸(DMPA)为支化单体,通过熔融缩聚法合成了第一至五代端羟基脂肪族超支化聚酯,采用旋转流变仪系统地研究了氢键作用对端羟基超支化聚酯熔体流变性能的影响.结果表明,与高代数超支化聚酯相比,低代数超支化聚酯的线性黏弹区较窄,松弛时间更长.无论是稳态剪切测试还是振荡测试,第一、二代端羟基超支化聚酯熔体均表现出假塑性流体的剪切变稀行为,而第三至五代端羟基超支化聚酯熔体则表现为牛顿流体的流变行为.端羟基超支化聚酯的流变行为均不遵循Cox-Merz方程.温度谱的测定发现,低代数超支化聚酯相对于高代数的结晶度更高.流变测试中所出现的现象都与分子间的氢键作用密切相关.     

带有端烷烃链的超支化聚酯的受限结晶及动态黏弹行为

以三羟甲基丙烷(TMP)为核,二羟甲基丙酸(DMPA)为支化单体,通过熔融缩聚法合成了第3代端羟基脂肪族超支化聚酯,并用十八酸对其进行端基改性,采用广角X射线衍射(WAXD)、示差扫描量热分析(DSC)及红外光谱(FTIR)研究了不同端基改性程度的超支化聚酯的结晶熔融行为及端烷烃链的构象和堆积结构随温度的变化,采用旋转流变仪研究了端烷烃链对脂肪族超支化聚酯熔体动态黏弹行为的影响.结果表明,这类改性超支化聚酯的结晶归因于长链端烷烃的有序排列,改性程度越高,衍射峰强度越大.受限结晶的端烷烃链在升温后并不能完全转变为无序的结构状态,改性超支化聚酯在"熔点"以上仍有部分有序结构存在.超支化聚酯的线性黏弹区随着端基改性程度的增大而逐渐变短,超支化聚酯的弹性逐渐增大,剪切变稀越明显.动态流变测试中所出现的现象与改性超支化聚酯中端烷烃链的受限密切相关.     

两亲性芳香族超支化聚酯的合成、表征及自组装研究

以1,2,4-苯三酸酐和聚乙二醇(聚乙二醇300、聚乙二醇400、聚乙二醇600)为反应单体,首次通过缩聚法合成了一系列两亲性芳香族超支化聚酯.通过FT-IR、1H NMR、GPC、DSC、TGA对超支化聚酯的结构和性能进行了表征,结果表明,利用缩聚法成功合成了两亲性超支化聚酯,并且两亲性超支化聚酯的热性能稳定.两亲性超支化聚酯在水中自组装成囊泡,可以用作微反应器和药物封装等.     

偏苯三酸酐-环氧丙烷丁基醚合成超支化碱溶性聚酯

通过1,2,4-偏苯三甲酸酐(TA)和环氧丙烷丁基醚(BGE)合成超支化碱溶性聚酯,利用合成聚合物分子外围的羧基与烯丙基缩水甘油醚(AGE)反应,在超支化聚合物分子外围引入反应性烯丙基醚.研究了树脂组成对感光性和碱溶性的影响;结果表明:调整反应物料配比,可以获得较好的碱溶性和光固化性能,其树脂的反差γ可达到3.92.     

基于酸-碱动态化学的超支化聚赖氨酸的合成

报道了离子型单体e-四氟硼酸盐-L-赖氨酸-N-羧酸酐(NH3BF4-Lys NCA)的合成,其化学结构和纯度采用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H-NMR)、碳谱(13C-NMR)、氟谱(19F-NMR)和飞行时间质谱(TOF-MS)进行了确认.在大于20oC时,单体中的胺基氟硼酸盐动态解离出e-胺基,原位转化为AB*型引发单体(inimer-NCA),一锅法生成了超支化聚赖氨酸氟硼酸盐.产物经脱盐处理,得到了支化度为0.34~0.53的超支化聚赖氨酸.在25~55oC聚合温度内,离子单体的开环聚合符合一级动力学,表观速率常数kp,obs从25oC的0.01 h~(-1)逐渐增大到55oC的0.11 h~(-1).采用异核单量子相干谱(1H-13C HSQC)、傅里叶变换离子回旋共振质谱(FTICR-MS)和FTIR对超支化聚合物的结构和聚合机理进行了解析.     

季戊四醇-偏苯三酸酐-环氧氯丙烷合成超支化聚合物

以季戊四醇为“中心核”,与1,2,4-偏苯三甲酸酐和环氧氯丙烷反应合成超支化碱溶性聚酯,利用合成聚合物分子外围的羧基与甲基丙烯酸缩水甘油酯反应,在超支化聚合物分子外围引入反应性甲基丙烯酰氧基.研究了树脂组成对感光性和碱溶性的影响.结果表明:通过调整分子外围的羧基及反应性甲基丙烯酰氧基含量,可以获得较好的碱溶性和光固化性能.     

由苯-1，2，4-三羧酸-1，2—酐和羟乙基哌嗪合成酰胺键、叔氨和酯键交替排列的水溶性超支化聚合物

基于官能团非等活性原理，由商品化多组分单体一步法合成了超支化聚合物． 用苯—1，2，4-三羧酸—1，2酐(BTAA)与羟乙基哌嗪(HEPZ)为原料，利用氨基和羟 基反应活性不同，制备了结构非对称超支化聚酰胺—酯．分别用红外、核磁共振确 定了所得聚合物的结构．该聚合物分子骨架中含有交替排列的酰胺键、叔氨和酯键 ，易溶于水．本合成方法原料易得、工艺简单，适合大量制备超支化聚合物．     

含光敏剂184结构的超支化碱溶性感光聚合物的合成及性能

以季戊四醇为“中心核”,通过与偏苯三酸酐,环氧氯丙烷反应合成超支化聚酯,利用合成聚合物分子外围的羧基与含环氧基的1-羟基环己基苯基酮、甲基丙烯酸缩水甘油酯反应合成分子末端含光敏剂结构的超支化碱溶性感光聚合物。聚合反应转化率在1 h内可达80%以上;合成聚合物的玻璃化转变温度为200℃,200℃以内无失重,200~300℃之间有轻微失重,其粘度表现为超支化聚合物的粘度特性,并且在碱性水溶液中溶解性好,无需外加光敏剂,在紫外光照射下便可固化、交联,具有较小的凝胶曝光能量E0(1×10-3~1×10-2J/cm2)和较好的光敏性。     

超支化聚酯修饰多壁碳纳米管

将碳纳米管先用V(H2SO4)∶V(HNO3)=3∶1混合溶液进行处理,再用V(H2SO4)∶V(H2O2=4∶1的混合溶液进一步酸化,制得含有羧基的碳纳米管。将羧基化碳纳米管与二氯亚砜反应使碳纳米管连接酰氯基团,利用酰氯基团与超支化聚酯上的羟基反应,将超支化聚酯接到碳纳米管的表面上,实现了碳纳米管的表面修饰。利用红外光谱、拉曼光谱、透射电镜观察分析测试结果表明,超支化聚酯以共价键形式连接到碳纳米管的表面。热失重分析结果表明,修饰密度为每321个C原子连接1个H20分子,每842个C原子上连接1个H40分子。修饰后的碳纳米管在有机溶剂中的溶解性能明显提高。     

由苯-1,2,4-三羧酸-1,2-酐和二乙醇胺合成结构非对称超支化聚(酰胺-酯)

通过准发散法和一步法由苯 1 ,2 ,4 三羧酸 1 ,2 酐 (BTAA)和二乙醇胺 (DEA)合成了新型水溶性结构非对称超支化聚 (酰胺 酯 ) .聚合物的端基可通过BTAA与DEA的加料比来调节 .产物结构经FTIR ,1 H NMR和TGA进行了表征 .在一步法中 ,当BTAA于DEA的加料比大于 2 0 4时 ,反应体系不易凝胶 ,当加料比小于 2时 ,体系容易发生交联 .在准发散法中 ,不用中间分离过程 ,采用合成树状大分子发散法相同的加料方式 ,可得到大分子产物     

超支化聚合物制备方法的研究进展

超支化聚合物是一类可以通过一步法来合成的具有高度支化结构的体型大分子.经过二十年的研究,超支化聚合物由于其独特的结构和性能特点以及可实现规模化生产的特点, 已经迅速成为一类重要的和具有广阔应用潜力的高分子材料.本文从单体类型的角度介绍了超支化聚合物的主要制备方法及其发展历程,主要涉及ABx型,AB*型,A2 B3型以及潜在ABx型单体(包括开环聚合和偶合单体法)等,同时论述了各制备方法的优点和局限性 .     

对苯二胺和均苯三酸及对氨基苯甲酸制备可溶性芳香聚酰胺共聚物的研究

分别通过一步加料和分步加料的方法,以对苯二胺(A2)、均苯三酸(B3)和对氨基苯甲酸(AB)为原料进行溶液缩聚反应,制备了具有良好溶解性的芳香聚酰胺共聚物.产物的结构通过IR、1H-NMR得到证实.采用IR和1H-NMR对一步加料共聚反应的共聚行为进行研究,并初步考察了3种不同单体对反应的影响.     

酶促开环聚合与自缩合乙烯基共聚合相结合制取超支化聚合物

在Novozyme 435脂肪酶催化下, 甲基丙烯酸羟乙酯(HEMA)引发己内酯(ε-CL)开环聚合反应, 得到一端为双键, 另一端为羟基的直链聚己内酯(PCL)产物; 将其端羟基官能化得到大分子AB*型单体, 与苯乙烯以原子转移自由基聚合(ATRP)反应形式进行自缩合乙烯基共聚合, 得到超支化结构聚苯乙烯-b-聚己内酯产物.     

Kinetic theory of self-condensing vinyl polymerization

This review introduces the kinetic theory of self-condensing vinyl polymerization (SCVP), including the SCVP of AB* inimers, the SCVP with non-equal reactivity between A* and B* groups, the SCVP in the presence of a small amount of multifunctional initiators, also the SCVP of both inimers and comonomers. The analytical expressions of various molecular parameters for the resulting hyperbranched polymers, such as the molecular size distribution function, the average molecular weight, the polydispersity index and the degree of branching, are reviewed systematically.     

Statistical and thermodynamic properties of binary self-condensing vinyl polymerization

The thermodynamic properties of a binary self-condensing vinyl polymerization system consisting of monomers and inimers are investigated by the principle of statistical mechanics.In detail,in terms of two types of canonical partition functions constructed from different viewpoints,the equilibrium free energy,the law of mass action and the size distribution of hyperbranched polymers are obtained.As an application,the specific heat,equation of state and isothermal compressibility concerning the polymerization...     

Synthesis of novel hyperbranched poly(ester‐amide)s based on neutral α‐amino acids via “AD + CBB′” couple‐monomer approach

A series of novel hyperbranched poly(ester‐amide)s (HBPEAs) based on neutral α‐amino acids have been synthesized via the “AD + CBB′” couple‐monomer approach. The ABB′ intermediates were stoichiometrically formed through thio‐Michael addition reaction because of reactivity differences between functional groups. Without any purification, in situ self‐polycondensations of the intermediates at elevated temperature in the presence of a catalyst afforded HBPEAs with multihydroxyl end groups. The degrees of branching (DBs) of the HBPEAs were estimated to be 0.40–0.58 and 0.24–0.54 by quantitative ¹³C NMR with two different calculation methods, respectively, depending on polymerization conditions and structure of monomers. The influences of catalyst, temperature, and intermediate structure on the polymerization process and molecular weights as well as properties of the resultant polymers were investigated. FTIR, NMR, and DEPT‐135 NMR analyses revealed the branched structure of the resultant polymers. The HBPEAs possess moderately high molecular weights with broad distributions, glass transition temperatures in the range of ?25.5 to 36.5 °C, and decomposition temperatures at 10% weight loss under nitrogen and air in the regions of 243.4–289.1 °C and 231.4–265.6 °C, respectively. Among them, those derived from D ,L ‐phenylalanine display the lowest degree of branching, whereas the highest glass transition temperature and the best thermal stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

A convenient room temperature polycondensation toward hyperbranched AB2‐type all‐aromatic polyesters with phenol terminal groups

As a convenient alternative to the classical melt polycondensation the one‐pot solution polycondensation of suitable AB₂ monomers under mild conditions has been successfully adapted to hyperbranched all‐aromatic polyester with phenol terminal groups. The polymerization was performed in solution at room temperature directly using commercially available 3,5‐dihydroxybenzoic acid as monomer and 4‐(dimethylamino) pyridinium 4‐tosylate as catalyst to suppress the formation of N‐acylurea. Different carbodiimides as coupling agents were investigated to find the optimal esterification conditions. The polymers have been characterized extensively and were compared with their well‐known analogs synthesized in melt. The characterization was carried out by NMR spectroscopy, size exclusion chromatography, and asymmetric flow‐field flow fractionation as an alternative separation technique for multifunctional polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5158–5168, 2009     

一锅法合成含磺酸基超支化聚氨酯

N-三羟甲基甲基氨基乙磺酸(TES)的胺基与异佛尔酮二异氰酸酯(IPDI)环上活性较高的NCO在低温15℃下发生选择性反应,生成AB3型单体.随后提高反应温度(70～90℃),使AB3型单体原位聚合,一锅法合成出含磺酸基超支化聚氨酯.随着聚合温度的提高,超支化聚氨酯的支化度、分子量及分子量分布系数变大.90℃时,聚合产物的Mn为22410,支化度达到0.87.以此含磺酸基超支化聚氨酯为基础制得的聚合物电解质膜具有良好的耐热性、机械强度,其锂盐室温(约25℃)的离子电导率为3.1×10-5S/cm,100℃达到1.4×10-3 S/cm.     

Hyperbranched methacrylates by self-condensing group transfer polymerization

The synthesis of hyperbranched methacrylates was achieved by self-condensing group transfer polymerization of 2-(2-methyl-1-triethylsiloxy-1-propenyloxy)ethyl methacrylate ( 1 ). “Back-biting” is shown to be the predominant side reaction. In spite of this, the compact nature of the hyperbranched molecules was demonstrated through SEC-viscosity measurements and comparison with a linear analogue. The degree of branching can be controlled by copolymerization with conventional monomers, e.g. MMA, and the living polymers can be used as macroinitiators for star-shaped polymers.