Multiple Endotherm Melting Behavior in Relation to the Morphology of Poly(3,3-bis(ethoxymethyl oxetane)
Abstract
Two crystalline melting peaks have been observed by differential scanning calorimetry for low molecular weight poly(3,3-bis- (ethoxymethyl) oxetane), polyBEMO, whereas only one melting peak has been observed for samples of higher molecular weight. Crystallization of low mol. wt. samples at large supercoolings produces the lower melting form, while low supercooling or annealing favors the higher melting species. Enthalpy of fusion values obtained by DSC for a multiple melting endotherm sample range from 28 to 39 j/g for crystallization temperatures from 58 to 35 C, respectively. Optical microscopy studies indicate that the lower melting peak corresponds to a spherulitic type of morphology and the higher melting peak correlates to a fine grained crystal structure. Wide angle x-ray powder diffraction studies do not detect differences in the crystal structures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 22, 1989
- Accession Number
- ADA204612
Entities
People
- Catherine J. Murphy
- J. J. Fay
- L. H. Sperling
Organizations
- Lehigh University