Cocrystallization in blends of poly(butylene terephthalate) and poly(ester-ether) segmented block copolymers

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5681589

Gallagher, K P; Zhang, Xuifang; Runt, J P ^[1]; Huynh-ba, Gia ^[2]; Lin, J S ^[3]

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1. Pennsylvania State Univ., University Park, PA (USA)
2. Du Pont de Nemours (E.I.) and Co., Wilmington, DE (USA). Research and Development Div.
3. Oak Ridge National Lab., TN (USA)

Only a few cases of cocrystallization (i.e. crystallization of two different polymers into the same crystalline lamellae) have been reported in the literature and, of these, all of the blended polymers are very similar in chemical structure. In addition, there is an indication that some of these blends only cocrystallize upon rapid crystallization. Blends of poly(butylene terephthalate) (PBT) and poly(ester-ether) segmented block copolymers (PEE) seem to be excellent candidates to exhibit cocrystallization for a number of reasons. First, it is well known that only the hard segments in PEE crystallize and they are identical in chemical structure to PBT. Second, pure PBT and PEE crystallize into the same unit cell and have identical lattice parameters. These two conditions that arise from the blocky nature of the copolymer make it possible, in principle, for both polymers to crystallize into the same lamellae. However, if PBT and PEE are separated into two phases in the melt, it is difficult to imagine cocrystallization occurring since both polymers could not be located at the crystallization growth front at the same time. Therefore, another necessary condition for cocrystallization is at least partial melt miscibility. Optical microscopy and small angle light scattering experiments were conducted on this blend, but no separate crystallization of the component polymers could be detected. This was taken as evidence that cocrystallization is likely in this blend. 8 refs., 4 figs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5681589
• Report Number(s): CONF-910812-4; ON: DE91012224
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
COPOLYMERS
CRYSTAL GROWTH
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALLIZATION
CRYSTALS
LIGHT SCATTERING
MICROSTRUCTURE
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POLYMERS
SCATTERING
SOLUBILITY