Monotropic Polymorphism in Ester-Based Phase Change Materials from Fatty Acids and 1,4-Butanediol
作者:S. Cabus、K. Bogaerts、J. Van Mechelen、M. Smet、B. Goderis
DOI:10.1021/cg400339z
日期:2013.8.7
This article reports on the synthesis, thermal behavior, and morphology of phase change materials based on diesters from 1,4-butanediol with palmitic (BD16), stearic (BD18), or behenic (BD22) acid. The crystalline contents and melting enthalpies of all substances exceed 90% and 180 J/g, respectively. The molecules display monotropic polymorphism. The metastable beta' form is built from outstretched molecules, whereas the denser, stable beta form is composed of molecules with a kinked conformation. BD18 and BD22 crystallize into the beta' form during cooling. Only BD18 transforms into the beta form during subsequent heating via a solid-solid transition. The resistance of BD22 to convert into the beta form is believed to originate from the lack of mobility associated with longer aliphatic chains. In contrast, the polymorphic conversion is thought to be very efficient and to take place during cooling for the shorter BD16 molecules. The hypothesis is put forward that the original BDI6 beta' nuclei are rapidly overgrown by the beta phase by which crystal growth is postponed to larger supercooling where the beta phase can grow from the melt. Consequently, BD16 only occurs in the beta form. The melt crystallization of BD18 and BD22 into the beta' form hardly requires any supercooling.
Viskositätsuntersuchungen an niedermolekularen Kettenmolekülen mit Sauerstoffkettengliedern
作者:G. von Bier
DOI:10.1002/macp.1951.020060111
日期:1951.3
AbstractUm den Einfluß von Sauerstoffatomen auf die Viskositätszahl von Kettenmolekülen zu prüfen. wurden die Distearate von Glyko, Di‐, Tri‐, Tetra‐ und Hexaglykol hergestellt und ihre Viskositätszahl bestimmt. als Vergleichssubstanzen wurden die Distearate von α,ω‐Diolen, und zwar Butandiol, Hexandiol, Decandiol, Hexadecandiol, Hergestellt und ebenfalls ihre Viskositätszahl bestimmt. Die aus den beiden Meß‐Serien erhaltenen Kurven divergieren mit steigendem Molekulargewicht. Für die Serie I besteht ein Zusammenhang von Zη und M, der geringer als linear ist. Für die Serie II besteht ein Zusammenhang der Form Zη = Käqu·n—c. Sauerstoffkettenglieder erhöhen stark die innere Beweglichkeit von Kettenmolekülen.
TOPICAL COMPOSITIONS COMPRISING TELMESTEINE FOR TREATING DERMATOLOGICAL DISORDERS
申请人:Sinclair Pharmaceuticals Limited
公开号:EP1670464B1
公开(公告)日:2011-03-23
POLYLACTIC ACID RESIN COMPOSITION AND MOLDED ARTICLE
申请人:Serizawa Shin
公开号:US20090054559A1
公开(公告)日:2009-02-26
Provided are a resin composition in which a moldability is improved at a temperature at which a polylactic acid resin is crystallized by adding both a carboxylic acid amide or a carboxylic acid ester which has at least one polar group in a molecule and a layered silicate to the polylactic acid resin, and a molded article.