Linked Life Data

17134202

Source:http://linkedlifedata.com/resource/pubmed/id/17134202

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
2006-11-30
pubmed:abstractText
By adjusting the molecular weight of the poly(l-lactic acid) (PLLA) component in poly(3-hydroxybutyrate) (PHB)/PLLA blends, we investigated the crystallization behaviors of the two components in their immiscible and miscible 50:50 blends by real time infrared (IR) spectroscopy. In the immiscible PHB/PLLA blend, the stepwise crystallization of PHB and PLLA was realized at different crystallization temperatures. PLLA crystallizes first at a higher temperature (120 degrees C). Its crystallization mechanism from the immiscible PHB/PLLA melt is not affected by the presence of the PHB component, while its crystallization rate is substantially depressed. Subsequently, in the presence of crystallized PLLA, the isothermal melt-crystallization of PHB takes place at a lower temperature (90 degrees C). It is interesting to find that there are two growth stages for PHB. At the early stage of the growth period, the Avrami exponent is 5.0, which is unusually high, while in the late stage, it is 2.5, which is very close to the reported value (n approximately 2.5) for the neat PHB system. In contrast to the stepwise crystallization of PHB and PLLA in the immiscible blends, the almost simultaneous crystallization of PHB and PLLA in the miscible 50:50 blend was observed at the same crystallization temperature (110 degrees C). Detailed dynamic analysis by IR spectroscopy has disclosed that, even in such apparently simultaneous crystallization, the crystallization of PLLA actually occurs faster than that of PHB. It has been found that, both in the immiscible and miscible blends, the crystallization dynamics of PHB are heavily affected by the presence of crystallized PLLA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
110
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24463-71
pubmed:dateRevised
2007-3-23
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Crystallization behaviors of poly(3-hydroxybutyrate) and poly(l-lactic acid) in their immiscible and miscible blends.
pubmed:affiliation
Department of Chemistry, School of Science and Technology, and Research Center for Environment Friendly Polymers, Kwansei-Gakuin University, Gakuen, Sanda 669-1337, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't