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首页> 外文期刊>Polymers for advanced technologies >Synthesis and characterization of hyperbranched polystyrene copolymers by atom transfer radical self-condensing vinyl copolymerization
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Synthesis and characterization of hyperbranched polystyrene copolymers by atom transfer radical self-condensing vinyl copolymerization

机译：原子转移自由基自缩合乙烯基共聚制备超支化聚苯乙烯共聚物及其表征

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摘要

A series of hyperbranched polystyrene copolymers were synthesized by atom transfer radical self-condensing vinyl copolymerization (ATR-SCVCP) of p-chloromethylstyrene (CMS) and styrene using the complex CuCl/2,2'-bipyridyl as catalyst. The composition and structures of these hyperbranched polystyrene copolymers were characterized by ~1H-NMR and ~(13)C-NMR spectroscopy, gel permeation chromatography (GPC), and elemental analysis. The thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The influence of the reaction conditions, including comonomer ratios, reaction time, and polymerization temperature, on the molecular weight and degree of branching (DB) of the resulting copolymers were investigated in detail. With increasing ratios of styrene in total monomers from 10 to 90%, the resulting copolymers have number-average molecular weights that change from 6.0 to 10.5 kDa, polydispersities from 2.96 to 4.74, and a degree of branching from 0.01 to 0.45. The experimental results indicated that the structures and properties can be controlled by adjusting the reaction conditions. The concentrations of styrene in the copolymers slightly affect the copolymer structures and T_g when they are less than 50 mol%, but have a large effect at greater concentrations. The results also show that the ATR-SCVP reaction does not follow a complete ATRP feature, but has some characteristics of step-growth polymerization.
机译：以配合物CuCl / 2,2'-联吡啶为催化剂，通过对氯甲基苯乙烯（CMS）和苯乙烯的原子转移自由基自缩合乙烯基共聚（ATR-SCVCP）合成了一系列超支化聚苯乙烯共聚物。这些超支化聚苯乙烯共聚物的组成和结构通过〜1H-NMR和〜（13）C-NMR光谱，凝胶渗透色谱（GPC）和元素分析进行​​了表征。通过差示扫描量热法（DSC）和热重分析（TGA）研究了热性能。详细研究了反应条件，包括共聚单体比例，反应时间和聚合温度，对所得共聚物的分子量和支化度（DB）的影响。随着苯乙烯在总单体中的比例从10％增至90％，所得共聚物的数均分子量从6.0 kDa变为10.5 kDa，多分散度从2.96变为4.74，支化度从0.01到0.45。实验结果表明，通过调节反应条件可以控制结构和性能。共聚物中苯乙烯的浓度小于50 mol％时，对共聚物结构和T_g的影响很小，但在较大浓度下有很大的作用。结果还表明，ATR-SCVP反应不遵循完整的ATRP功能，但具有逐步增长聚合的某些特征。

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