Poly(3-hydroxyoxetane)―An analog of poly(vinyl alcohol): synthesis, characterization, and properties
Poly(3-hydroxyoxetane)―An analog of poly(vinyl alcohol): synthesis, characterization, and properties
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聚（3-羟基氧杂环丁烷）——聚（乙烯醇）的类似物：合成、表征和性能
DOI：
10.1002/pola.1989.080270918
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
R. Nieman
中科院分区：
文献类型：
--
作者：
E. J. Vandenberg;J. Mullis;R. S. Juvet;T. Miller;R. Nieman
由3-羟基氧杂环己烷(HO)形成的自发性聚合物是由Wojowicz和Polak首次报道的，它是一种具有OCH2CH(OH)CH2OH端基的线性、低分子、水溶性、无规、高结晶度的聚(3-羟基氧杂环己烷)(Pho)。这种无规聚合物的高度结晶性质可能与无规聚乙烯醇的结晶性质有关，因为pho可以被认为是乙烯醇和甲醛的共聚物。在室温下放置几个月，Ho在空气中氧化生成的羧酸明显地通过阳离子聚合形成自发的PhO。在HO中加入2%的羟基乙酸即可实现聚合反应。这种不寻常的阳离子聚合速率随着酸强度的增加而大大增加，例如，三氟甲磺酸与纯Ho发生爆炸性反应。提出了阳离子聚合的反应机理。在I-Bu3Al-0.7H2O阳离子催化剂作用下，HO的三甲基硅基醚聚合，再经水解反应制得高相对分子质量、水溶性、线性无规、高结晶度的磷酸盐(熔点=155°C)。在400 MHz频率下发现了两种不同类型的亚甲基单元，甲基质子解偶联，建立了两种测定邻苯二甲酸二异辛酯的~1H-核磁共振方法。此外，还建立了一种测量HO聚合物支化程度的~1H-核磁共振方法。以Tm=223°C的水不溶组分的形式，以较低的产率获得了等规度提高(80%)的高相对分子质量的线形磷光催化剂。
The spontaneous polymer formed from 3-hydroxyoxetane (HO), as first reported by Wojtowicz and Polak, is linear, low molecular weight, water-soluble, atactic, poly(3-hydroxyoxetane) (PHO) of high crystallinity with OCH2CH(OH)CH2OH end units. The highly crystalline nature of this atactic polymer may be related to the crystalline nature of atactic poly(vinyl alcohol) since PHO can be considered a copolymer of vinyl alcohol and formaldehyde. Spontaneous PHO apparently is formed in a cationic polymerization by the carboxylic acids produced by the air oxidation of HO on standing at room temperature for several months. The polymerization can be duplicated by the addition of 2% hydroxyacetic acid to HO. The rate of this unusual cationic polymerization increases greatly with acid strength, e.g., trifluoromethanesulfonic acid reacts explosively with pure HO. A mechanism is proposed for this cationic polymerization. High molecular weight, water-soluble, linear atactic, and highly crystalline PHO (mp = 155°C) was made by polymerizing the trimethylsilyl ether of HO with the i-Bu3Al–0.7 H2O cationic catalyst followed by hydrolysis. Two 1H-NMR methods for measuring the tacticity of PHO were developed based on finding two different types of methylene units at 400 MHz with the methine protons decoupled. Also, an 1H-NMR method was developed for measuring branching in HO polymers. High molecular weight, linear PHO with enhanced isotacticity (80%) has been obtained in low yield as a water-insoluble fraction with Tm = 223°C. The low molecular weight PHO prepared previously by the base-catalyzed, rearrangement polymerization of glycidol is highly branched.