Premium
Miscibility, melting, and crystallization behavior of poly(hydroxybutyrate) and poly( D , L ‐lactic acid) blends
Author(s) -
Gunaratne L.M. Wasantha K.,
Shanks R.A.
Publication year - 2008
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.21051
Subject(s) - miscibility , materials science , small angle x ray scattering , differential scanning calorimetry , crystallinity , crystallization , chemical engineering , polymer , recrystallization (geology) , polymer blend , polymer chemistry , composite material , copolymer , scattering , thermodynamics , paleontology , physics , biology , optics , engineering
Melting behavior and crystal morphology of poly(3‐hydroxybutyrate)‐poly( D , L ‐lactic acid) (PHB‐RPLA) blends with various compositions have been investigated by modulated temperature differential scanning calorimetry (mt‐DSC), polarized optical thermomicroscopy (POTM), modulated force thermomechanometry (mf‐TM), and small angle X‐ray scattering (SAXS). Thermal properties were investigated after fast cooling crystallization treatment. Multiple melting peak behavior was observed for all polymers. mt‐DSC data revealed that PHB‐RPLA blends undergo melting‐recrystallization‐remelting during heating, as evidenced by exothermic peaks in the nonreversing heat capacity. A decrease in degree of crystallinity due to significant melt‐recrystallization was observed for blends. PHB‐RPLA showed different crystal morphologies for various compositions. POTM results showed that the crystallization rates and sizes of spherulites were significantly reduced as RPLA content increased. mf‐TM results confirmed miscibility of these two polymers. SAXS data provided evidence of lamella thickness of blends, which increased with increasing RPLA content. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers