Synthesis of versatile poly(PMMA‐b‐VI) macromonomer‐based hydrogels via infrared laser ignited frontal polymerization

In this work, poly((PMMA‐b‐VI)‐co‐AA) (MMA = methyl methacrylate; VI = 1‐vinylimidazole; AA = acrylic acid) hydrogels and poly((PMMA‐b‐VI)‐co‐AA)/TPU (TPU = thermoplastic polyurethane) IPN (interpenetrating polymer networks) hydrogels have been fabricated via versatile infrared laser ignited frontal polymerization by using poly(PMMA‐b‐VI) macromonomer as the mononer. The frontal velocity and T_max (the highest temperature that the laser beam detected at a fixed point) can be adjusted by varying monomer weight ratios, the concentration of BPO (BPO = benzoyl peroxide) and the amount of TPU. Moreover, the addition of TPU enhances the reactant viscosity to suppress the “fingering” of frontal polymerization (FP) and decrease T_max of the reaction, providing a new inert carrier (TPU) to assist FP. Through the characterization of Fourier transform‐infrared spectroscopy (FT‐IR), scanning electron microscope (SEM), and differential scanning calorimetry (DSC), the desired structure can be proved to exist in the IPN hydrogels. Furthermore, poly((PMMA‐b‐VI)‐co‐AA)/TPU IPN hydrogels possesses more excellent mechanical behaviors than hydrogels without IPN structure. Besides, the poly((PMMA‐b‐VI)‐co‐AA) hydrogels present splendid sensitive properties toward substances of different flavor including sourness (CA, citric acid or GA, gluconic acid), umami (SG, sodium glutamate), saltiness (SC, sodium chloride), sweetness (GLU, glucose), enabling their potential as artificial tongue‐like sensing materials. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1210–1221     

RAFT copolymerization of methacrylic acid and poly(ethylene glycol) methyl ether methacrylate in the presence of a hydrophobic chain transfer agent in organic solution and in water

RAFT polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA, 1100 g mol^?1) was first performed using cyanoisopropyl dithiobenzoate (CPDB). The control of PEGMA homopolymerization, carried out in THF ([PEGMA] = 40 wt %) at 65 °C (reflux) using 2,2′‐Azobis(isobutyronitrile) (AIBN) as initiator, was shown by the linear increase of molar masses and the low polydispersity indices (PDI) observed with conversion and also by the determination of a high chain transfer constant (C_tr = 9.1) for CPDB in this system. Copolymerization of PEGMA with methacrylic acid (MAA) ([PEGMA]/[MAA] = 40/60) was then undertaken first in dioxane at 85 °C. High conversion (89%) was obtained in 3 h without any composition drift and with a good level of control (PDI < 1.40). When the polymerization was performed in water, a strong increase in polymerization rate was observed with almost quantitative conversion (98%) in 2 h without affecting the level of control of the final copolymers (PDI ～ 1.30). These last results were tentatively explained by the formation of hydrophobic domains in which the polymerization occurred as in bulk. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3045–3055, 2009     

疏水改性聚丙烯酰胺的合成

表面活性大单体;疏水改性聚丙烯酰胺的合成     

聚硅氧烷大单体与丙烯酸酯乳液共聚合

乳液聚合;交联程度;聚硅氧烷大单体与丙烯酸酯乳液共聚合     

梳形接枝共聚物的合成(Ⅱ)——载体化钌卡宾络合物催化降冰片烯基聚苯乙烯的开环岐化聚合

由石油化工副产C₅馏份提取双环戊二烯(DCPD)、以聚合物负载三氟化硼为催化剂进行DCPD与烯丙基氯(AC)的Diels-Alder反应合成5-氯甲基-2-降冰片烯(NBCH₂Cl),经锂代反应后用以引发苯乙烯的活性阴离子聚合合成了降冰片烯(NB)基聚苯乙烯(PS)大分子环烯单体NB-PS,在聚合物负载钌卡宾络合物[RuCl₂(PPh₃)₂(=C=CHtBu)]催化(引发)作用下进行大分子单体NB-PS的开环歧化聚合(ROMP)合成了梳形接枝共聚物PNB-g-PS.实验结果表明所合成聚合物负载硼、钌络合物催化剂的性能均明显优于对应非负载体.讨论了上述催化剂的聚合物载体效应的机理及温度、溶剂等对活性阴离子聚合反应的影响.     

含乙烯基超支化聚(酯-酰胺)大单体的合成

以顺丁烯二酸酐、二乙醇胺、邻苯二甲酸酐等为原料,利用官能团活性的差异,通过逐步展开的方法合成了含有双键和端羟基的聚（酯-酰胺）型分子结构的超支化大单体（3）。IR分析表明：3的分子末端为大量伯羟基,具有较高的反应活性;3含有可供聚合的乙烯基,将3与其它乙烯基单体共聚可以获得含超支化结构的共合物。     

结构规整的高密度两亲性接枝聚合物刷的合成及其自组装研究

大分子单体通过两种可控聚合方法, 即开环易位聚合(ROMP)和原子转移自由基聚合(ATRP)的联用, 合成一种新型两亲性接枝聚合物刷. 具有高环张力的降冰片烯单侧链大分子单体norbornene-graft-poly(ε-caprolactone)/Br (PCL- NBE-Br)首先进行ROMP反应, 生成聚合物主链, 每个单体单元上含有一条PCL链和一个溴官能团; 然后用含溴的ROMP聚合物poly(norbornene)-graft-poly(ε-caprolactone)/Br (PCL-PNBE-Br)作为大分子引发剂引发单体2-(dimethyl- amino)ethyl methacrylate)的ATRP反应, 生成结构明确的高密度两亲性接枝聚合物刷poly(norbornene)-graft-poly(ε- caprolactone)/poly(2-(dimethylamino)ethyl methacrylate) (PCL-PNBE-PDMAEMA), 其主链每个单体单元上均含有一条疏水性PCL接枝链和一条亲水性PDMAEMA接枝链. 最后, 研究此类高密度两亲性接枝聚合物刷的自组装行为, 用动态激光光散射(DLS)研究其在混合溶剂(THF/H2O)中的胶束行为, 考察胶束溶液的浓度以及不同长度的亲水性接枝链对胶束尺寸的影响; 利用透射电镜(TEM)观察胶束为球形, 具有类似线团或草莓状的形态.     

Amphiphilic polymer gel electrolytes. II. Influence of the ethylene oxide side‐chain length on the gel properties

Amphiphilic polymers consisting of copolymethacrylates carrying about 26 wt % ethylene oxide [(EO)_n] side chains of different lengths were used as matrices in gel electrolytes. The gel electrolytes were composed of 30 wt % copolymer and 70 wt % 1 M LiPF₆ in a mixture of ethylene carbonate and γ‐butyrolactone (2/1 w/w). The coordination of lithium ions by the (EO)_n side chains in competition with the solvent was studied by Raman spectroscopy. A significantly stronger lithium coordination was observed when the gel electrolyte was based on a copolymer carrying (EO)₉ units in comparison with copolymers having (EO)₁, (EO)₂, and (EO)₄ units. Despite the observed stronger lithium coordination by (EO)₉ units in the gel, the ion conductivity was not significantly lower with respect to the gels based on the other copolymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1519–1524, 2001