Stress-induced structural changes in thermoplastic composites

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1990

OSTI ID:6976989

Kitano, A

Polymeric Composites: Cyclic stress effects on PEEK (Poly-ether-ether-ketone) matrix thermoplastic composite system were examined by thermal-analysis techniques: DSC (Differential Scanning Calorimeter), DMA (Dynamic Mechanical Analysis), TMA (Thermomechanical Analysis), TGA (Thermogravimetric Analysis), TMA (Thermomechanical Analysis), TGA (Thermogravimetric Analysis), DGT (Density Gradient Technique), and WAXS (Wide angle X-ray Scattering). These measurements identified for the first time stress-induced crystallization of PEEK below the glass transition temperature (Tg). Also, PEEK crystallization above T[sub g] was kinetically studied by DSC and DMA, and a previously developed dual-crystallization methodology was extended to account for the influence of stress on crystallization. Finally, a fatigue kinetic model for un-notched PEEK films and a crack propagation model for PEEK composites were also developed providing a relation between matrix morphology and end-use performance. Collectively, this work established the importance of structural changes in thermoplastic-based composites that can be both monitored and influenced by dynamic (cyclic) mechanical experiments.

• Research Organization: Washington Univ., Seattle, WA (United States)
• OSTI ID: 6976989
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
COMPOSITE MATERIALS
CRYSTALLIZATION
MATERIALS
MATRIX MATERIALS
MORPHOLOGY
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PLASTICS
POLYMERS
STRESS ANALYSIS
STRESSES
SYNTHETIC MATERIALS
THERMODYNAMIC PROPERTIES
THERMOPLASTICS
TRANSITION TEMPERATURE