The Effect of the Environment on the Mechanical Bahavior of Semi-Crystalline Polymers at High Pressures.
Abstract
The effect of a silicon oil environment on the mechanical behavior of the semicrystalline polymers polyethylene, polypropylene and polyoxymethylene, under conditions of superposed hydrostatic pressure have been studied. These studies show that silicon oil does not affect the modulus and yield stress of these polymers: thus the modulus and yield stress increase with pressure but stress-strain curves of samples exposed to the silicon oil and sealed from it coincide in this region. Silicon oil does however affect both the mechanism and extent of plastic deformation occurring in these polymers. Thus samples of polyethylene and polypropylene which are exposed to the oil show a transition in the mode of plastic deformation from neck formation and propagation at test pressures below 1 to 2 kbar to enhanced ductility without strain hardening. Similar behavior is observed in polyoxymethylene but is less pronounced. In terms of morphology this affect is suggested as possibly occurring due to lamellar slip facilitated by silicon oil plasticized inter-lamellar regions and further experiments are being undertaken to verify this. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 10, 1976
- Accession Number
- ADA032741
Entities
People
- E. Baer
- S. Kapur
Organizations
- Case Western Reserve University