Poly[3,3‐bis(hydroxymethyl) oxetane]—an analog of cellulose: Synthesis, characterization, and properties
Poly[3,3‐bis(hydroxymethyl) oxetane]—an analog of cellulose: Synthesis, characterization, and properties
复制标题
聚[3,3-双（羟甲基）氧杂环丁烷]——纤维素类似物：合成、表征和性能
DOI：
10.1002/pola.1989.080270917
复制
发表时间：
1989
期刊：
影响因子：
--
通讯作者：
R. S. Juvet
中科院分区：
文献类型：
--
作者：
E. J. Vandenberg;J. Mullis;R. S. Juvet
以3，3-双羟甲基氧杂环丁烷的三甲基硅醚为原料，在i-Bu 3Al-0.7H2O阳离子催化剂作用下，低温聚合，然后水解，制备了高相对分子质量（ηinh达5.2）的聚[3，3-双羟甲基氧杂环丁烷]（PBHMO）。PBHMO是晶体，非常高的熔点（314°C）和高度不溶性，非常像它的类似物，纤维素。它在30°C下可溶于75%的H2SO 4中，65%转化为酸性硫酸酯;这些条件可用于粘度测量，因为降解速率低，并且至少比纤维素在该溶剂中的降解速率低一个数量级。PBHMO可以使用较低熔点的二乙酸酯（184°C）制备为取向膜和纤维，其可以是熔融或溶液（CHCl 3）制造的，然后将取向形式皂化成取向的PBHMO。BHMO可以在室温下用三氟甲磺酸催化剂直接聚合成低分子量的，可能有些支化的PBHMO（ηinh 0.1）。聚（3-甲基-3-羟甲基氧杂环丁烷），（PMHMO），通过与PBHMO相同的方法以高分子量（ηinh高达3.8）制备，比PBHMO更易溶且熔点更低（165°C），似乎是无规立构的，并且可以在195°C下压缩模塑成容易取向的坚韧透明膜。BHMO与MHMO的共聚物在整个组成范围内都是结晶的，Tm随组成线性变化，这是聚合物领域中同晶性的一个新例子。
Poly[3,3-bis(hydroxymethyl)oxetane], PBHMO, was prepared in high molecular weight (ηinh up to 5.2) by polymerizing the trimethylsilylether of 3,3-bis(hydroxymethyl)oxetane with the i-Bu3Al–0.7 H2O cationic catalyst at low temperature, followed by hydrolysis. PBHMO is crystalline, very high melting (314°C) and highly insoluble, much like its analog, cellulose. It is soluble in 75% H2SO4 at 30°C, being 65% converted to the acid sulfate ester; these conditions are useful for viscosity measurement, since the degradation rate is low and at least an order of magnitude less than for cellulose in this solvent. PBHMO can be prepared as oriented films and fibers using the lower melting diacetate (184°C) which can be melt or solution (CHCl3) fabricated and then the oriented forms saponified to oriented PBHMO. BHMO can be directly polymerized to low molecular weight, perhaps somewhat branched, PBHMO (ηinh 0.1) with trifluoromethanesulfonic acid catalyst at room temperature. Poly(3-methyl-3-hydroxymethyloxetane), (PMHMO), prepared in high molecular weight (ηinh up to 3.8) by the same method used for PBHMO, is more soluble and lower melting (165°C) than PBHMO, appears to be atactic and can be compression molded at 195°C to a tough, clear film which is readily oriented. Copolymers of BHMO with MHMO are crystalline over the entire composition range with a linear variation of Tm with composition, a new example of isomorphism in the polymer area.