کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1987363 | 1540286 | 2011 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Microbial medium chainlength poly[(R)-3-hydroxyalkanoate] shows liquid crystal behaviour Microbial medium chainlength poly[(R)-3-hydroxyalkanoate] shows liquid crystal behaviour](/preview/png/1987363.png)
Medium chainlength (mcl) polyhydroxyalkanoates (PHAs) are a class of polymers receiving attention because of their potential as renewable, biodegradable and high tech properties. Unlike most short chain PHAs, mcl-PHAs are low crystallinity and elastomeric in character. In this paper we wish to point out that in their broad properties mcl-PHAs might be classified as thermotropic liquid crystals with dynamic conformational disorder and long range orientational order. As the characterization of mcl-PHAs progresses, their similarities to liquid crystalline elastomers are noteworthy. Wunderlich coined the acronym CONDIS from the words “conformational disorder” to categorize this type of liquid crystal. Thermal analysis reveals a Tg of −40 to −45 °C with several Tm peaks. The chemistry of the elastomer from 13C NMR confirms the poly(3-hydroxynonanoate), PHN, composition of the starting material along with two other samples containing double bonds: PHNU-18 and PHNU-31 where the numeral stands for the percent of double bonds.
Journal: International Journal of Biological Macromolecules - Volume 48, Issue 2, 1 March 2011, Pages 271–275