新型双功能性超支化聚合物的制备及表征

首先以烯丙基缩水甘油醚与N-氨乙基哌嗪反应合成新型B3单体,然后分别以六亚甲基二异氰酸酯和1,6-己二硫醇为A2单体与上述B3单体反应,利用异氰酸-羟基以及巯基-烯的反应,合成了同时含有羟基和烯丙基的双功能性超支化聚(氨酯-胺)和聚(硫醚-胺)。研究了单体种类及投料比与合成的超支化聚合物的化学与拓扑结构的关系。通过红外吸收光谱、核磁共振氢谱和凝胶渗透色谱表征了超支化聚合物的分子结构和化学组成。结果表明:该B3单体同时带有3个羟基与3个烯丙基,当A2和B3单体投料比(物质的量之比)为0.825∶1时,可以成功制备较高分子量的双功能性超支化聚合物。     

三元非等活性自缩合乙烯基聚合体系的Z均回转半径

利用Monte Carlo模拟方法研究了由单体、引发单体和引发核组成的三元自缩合乙烯基聚合反应体系. 重点考察了两类活性基团反应活性的差异、引发单体分数、引发核的配比及活性基团数等因素对体系中无核和有核两类超支化高分子Z均回转半径的影响. 结果表明, 这些因素对超支化高分子的结构和尺度影响显著, 因而通过调节有关参数可以实现对超支化高分子结构和尺度的调控.     

超支化聚合物接枝改性碳纳米管及其分散性能

将碳纳米管用c(K2Cr2O7)=0.25 mol/L,c(H )=1 mol/L混合溶液进行处理,制得表面含有活性羟基的碳纳米管. 在催化剂的存在下,以CNTs为反应中心核,氧化处理后的CNTs表面上的活性羟基与A2B型单体发生一步缩聚反应,将超支化聚合物接到碳纳米管的表面上,实现了碳纳米管的表面修饰. 探讨了反应条件对接枝在CNTs表面上的超支化聚合物(HPAE)量的影响,当反应温度为120 ℃,反应时间为10 h,反应配料比n(CNTs-OH):n(A2B单体)=1:6时,固载量达到0.255. FTIR、XPS、TEM的表征结果证明,CNTs接枝上了超支化聚合物. 透光度的测定和静置实验表明,超支化聚合物接枝改性CNTs在丙酮、乙醇、水等溶剂中具有很好的分散性能.     

可聚合的氧化还原引发体系

胺类具有还原性,可以与多种氧化剂构成氧化还原引发体系,胺类可产生自由基,引发乙烯基单体聚合.若乙烯基单体同时含有胺类基团,则这类自身还原性引发型单体在氧化剂存在的情况下既参与链引发又参与链增长,因此可以形成超支化聚合物.本文首先回顾了胺类氧化还原体系及其引发机理,然后总结自身还原性引发型单体分别与过氧化物、二芳酮、高氧...     

通过自缩合乙烯基氧阴离子聚合制备超支化聚甲基丙烯酸羟丙酯

由甲基丙烯酸羟丙酯通过自缩合乙烯基氧阴离子聚合(self-condensing vinyl oxyanionic polymerization)制备了端羟基的超支化聚甲基丙烯酸酯. 以氢化钾(KH)和冠醚的复合物为引发剂时, 可以得到高分子量的聚合物. 用¹H NMR和¹³C NMR谱图证实了聚合物的超支化结构. 由于在聚合过程中存在质子转移反应, 引发剂与单体的摩尔比会影响所得聚合物的结构. 超支化聚合物的玻璃化转变温度在58.1～81.4 ℃之间, 且随着引发剂与单体的比例的减小而降低. 当引发剂与单体等摩尔比时, 所得聚合物的支化度为0.49.     

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.     

可紫外光固化的超支化聚硅氧烷合成及固化研究

同线型聚硅氧烷聚合物相比，超支化聚硅氧烷聚合物具有低粘度、高反应活性和良好的相容性等特点，其中以制备超支化的聚硅氧烷基硅氧烷和聚烷氧基硅氧烷为主．对于超支化聚硅氧烷主要是以ABx（X=2～6）（其中A为双键，B为硅氢键）型单体为原料，在氯铂酸或Pt／C的催化下，通过硅氢加成反应一步制备，最终聚合物的端基（B）为硅氢键，而双键则完全反应，此外也可通过含不同数目烷氧基硅烷的水解缩合制备超支化聚硅氧烷．     

由A_2, B_2和BB’_2型单体合成超支化共聚物──Ⅳ.N-乙基乙二胺、4,4’-三亚甲基二哌啶与二乙烯基砜的共聚反应

将二官能度单体（Ａ_２）和三官能度单体（ＢＢ’２）反应合成超支化聚合物的方法推广应用于共聚反应．用Ａ２——二乙烯基砜（ＤＶ）,Ｂ２——４,４’－三亚甲基二哌啶（ＴＭ ＤＰ）和ＢＢ’２——Ｎ－乙基乙二胺（ＮＤＡ）单体直接反应合成了超支化共聚物．聚合反应时,ＴＭＤＰ和ＮＤＡ的仲胺基与ＤＶ的双键迅速加成,生成一种带有双键和伯胺基的ＡＢ’２型中间体,该中间体进一步聚合得到超支化聚砜胺．用Ｆｏｕｒｉｅｒ变换红外光谱（ＦＴＩＲ）,色－质联用谱（ＬＣ／ＭＳＤ）等测试手段验证了这一反应机理．产物的支化度随着ＴＭＤＰ与ＮＤＡ的加料比增大而减小,因而可通过这种共聚合方法来控制超支化聚合物的支化度．当ＴＭＤＰ与ＮＤＡ的加料比大于或等于４时,产物是半结晶的．     

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.     

由4',4''-二羟基-2-甲酸－三苯基甲烷及其衍生物制备高碳超支化芳香聚酯

合成了一系列含羟基和乙酰氧基的超支化聚酯,将4',4'二羟基-2-甲酸－三 苯基甲烷（酚酞啉）直接缩聚和将4~＇,4~＂-二羟基-2-甲酸－三苯基甲烷进行酯 交换反应都成功得到了超支化聚酯,以PS作标准物,由GPC测得的重均分子量为 2000到8000,~13C NMR测试表明聚合物支化度略高于50%,聚酯的玻璃化转变温度 依赖于末端和侧基官能团类型,该超支化聚酯末端含有反应性官能团,具有类似线 性高分子的高的热稳定性,相比之下,由于其大分子的形状和官能团的影响,末端 为乙酰氧基的超支化聚枉费显示了优良的溶解性能,这与一般线性高分子大不相同 ,由于氢键的存在,末端为羟基的超支化聚酯的溶解性能不佳,但是酸酯显示了 优良的溶解性能,这与一般线性高分子大不相同,由于氢键的存在,末端为羟基的 超支化聚枉费的溶解性能不佳,但是酸化可破坏氢键网络,得到的超支化聚酯可深 于一般有机溶剂。     

Synthesis and application of water-soluble hyperbranched polyester modified by trimellitic anhydride

In this paper, we aimed to synthesize a water-soluble hyperbranched polyester with pentaerythritol and trimethylolpropane as branching centers and trimellitic anhydride as waterborne functional groups. The condition and principle of water-soluble hyperbranched resin synthesis were explored. The trimellitic anhydride was used to synthesize water-soluble hyperbranched resin at the most appropriate temperature of 160–170°C. The properties of the resin were characterized by FTIR, hydroxyl value, molecular weight, stability, viscosity, and then the relationship among them under different synthesis conditions was further studied. Results indicated that the water-soluble hyperbranched resin had no delamination for more than 6 months at a solid content higher than 60%. Moreover, the resin was mutual soluble with water at any proportion and kept clear and transparent at same time. After water-soluble hyperbranched resin mixing with amino resin in a ratio of 2.5:1, and curing at 130–135°C for 2 hours, the chemical and mechanical properties of the coating were further measured and characterized.     

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．     

Amphiphilic protic anionic oligomeric ionic liquids of hyperbranched structure

The method of synthesizing anionic amphiphilic protic hyperbranched ionic liquids with the controlled ratio between hydrophilic ionic-liquid groups and hydrophobic alkyl urethane fragments in the oligoester nucleus shell is developed. These compounds are synthesized by the interaction of excess hyperbranched polyesterpolyol containing 32 terminal hydroxyl groups with n-octadecyl isocynate followed by the acylation of hydroxyl groups by phthalic anhydride or 2-sulfobenzoic anhydride and the neutralization of the formed carboxyl or sulfonic groups by N-methylimidazole or 1,2,4-1H-triazole. With a rise in the content of alkyl urethane fragments, the synthesized compounds form the crystalline phase. Structuring of the system leads to different effects of the degree of ionicity of ionic-liquid groups on proton conductivity, which is within 10^–7–10^–4 S/cm at 100–120°C under anhydrous conditions. The thermal stability of the hyperbranched ionic liquids is determined by the nature of ionic-liquid groups and the amount of the introduced alkyl urethane fragments; it is in the range of 170–270°C.     

Synthesis of novel low-viscosity liquid epoxidized aromatic hyperbranched polymers

Low-viscosity liquid epoxidized aromatic hyperbranched polymers are synthesized by the reaction between epichlorohydrin (ECH) and carboxy-end hyperbranched polymers prepared from low-cost products trimellitic anhydride (B₃ TMA) and dihydroxy alcohols (A₂). The low-viscosity property, especially the lowest viscosity of epoxidized aromatic hyperbranched polymers is only 350 cp which has not reported among epoxidized aromatic hyperbranched polymers before, make them can be used to coatings and adhesion fields without organic solvent hopefully. The properties of the epoxidized aromatic hyperbranched polymers are measured by GPC, FT-IR and viscometer.     

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...     

UV固化超支化聚酯树脂的制备研究

以双季戊四醇（DPE）为超支化核心，与偏苯三酸酐（TMA）和甲基丙烯酸缩水甘油酯（GMA）反应合成了超支化聚酯树脂。偏苯三酸酐半酯化后产生羧基，羧基再与GMA中的环氧基反应提供UV固化性能。同时研究了温度、催化剂等因素对反应的影响。     

Synthesis of Mesoporous Alumina Using Carboxyl Functional,Hyperbranched Polyesters as Templates

A series of mesoporous aluminas have been synthesized using commercial hyperbranched polyesters of the second to fourth generation as porogens. To achieve a suitable interaction between the polymer and the aluminium source, aluminium sec‐butoxide, the terminal hydroxyl groups of the hyperbranched polymer were first reacted by succinic anhydride. The mesoporous aluminas were analyzed by nitrogen adsorption/desorption, X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). No dependence of the generation of the hyperbranched template on pore size was found in this study. Instead the pore size appears to depend on the amount of water added to the reaction mixture as well as the concentration of the hyperbranched polymer.     

Synthesis and Properties of Hyperbranched Polyimides Combined with Silica

Summary: The novel hyperbranched polyimide - silica hybrid materials containing theoretically 16 wt% of an inorganic phase were prepared via a sol-gel process. An amine terminated polyimide precursor (hyperbranched polyamic acid) was prepared from commercially available monomers 4,4′,4″-triaminotriphenylmethane and 4,4′-oxydiphthalic anhydride in molar ratio 1:1. Tetramethoxysilane and/or 3-glycidoxypropyltrimethoxysilane (also used as a coupling agent) were used as silica precursors. During thermal exposition the polyimide precursor was transformed to hyperbranched polyimide and hydrolyzed alkoxy groups reacted mutually to form silica. The final products were self-standing films, whose structure was characterized by using IR and ¹³C and ²⁹Si solid state NMR spectroscopy. The influence of the amount of silica and/or coupling agent on their structure and thermal properties was described.     

Hemocompatibility and ultrafiltration performance of PAN membranes surface‐modified by hyperbranched polyesters

Maleic anhydride was grafted onto a polyacrylonitrile (PAN) membrane surface via ultraviolet irradiation. Then, hyperbranched polyester, with varying numbers of hydroxyl end‐groups (H20, H30, and H40), was grafted onto the PAN membrane surface by the reaction of hydroxyl groups with anhydride groups of maleic anhydride. The modified membranes were characterized by scanning electron microscopy, static water contact angle, and attenuated total reflectance‐Fourier transform infrared spectroscopy measurements. The modified membranes showed a higher water flux and better antifouling properties than pristine PAN membranes, and their hydrophilicity was significantly improved. Membrane biocompatibility was characterized by platelet adhesion, and the results indicate that the modified membranes exhibited good biocompatibility. Copyright © 2016 John Wiley & Sons, Ltd.     

可光固化星形超支化聚酯的合成与表征

描述了基于季戊四醇和１，２，４ 苯三甲酸酐，经由甲基丙烯酸缩水甘油酯和甲基丙烯酸酐改性的系列超支化聚酯的“发散”合成方法，即合成反应从“中心核”开始，逐步向外扩展，控制链增长，每个分子形成具有大约８，１２和１６个甲基丙烯酸酯双键的超支化臂。这种星形聚酯分子具有三维球状结构，不会产生分子链间的缠结，在辐射固化涂层和粘合剂等领域具有广阔的应用前景．