Study of the Molecular Stress Response of Solid Polymers by Photoelastic Methods
Abstract
The molecular stress response of solid amorphous polymers was studied by measurements of the stress-optical coefficient (SOC) as a function of temperature. Effects of stereospecific structure were investigated with polymeth 1 methacrylate (isotactic, syndiotactic, stereo-block, atactic) and polystyrene (isotactic, atactic). The alpha methyl effect was investigated using polymethyl acrylate, methyl acrylate/methyl methacrylate copolymer (50/50), polymethyl alphachlor acrylate and poly alpha-methyl styrene as comparison materials. Plasticizer effects were studied with polymethyl methacrylate containing 5, 10, and 15% dibutyl phthalate, and elasdulus measure ments were carried out to complement the stress optical data. An electronic Senarmont birefrin gence compensator was developed which gives approximately 60 times the precision of the visual Senarmont compensator. Improvements in the technique of low-temperature SOC measurements allow the temperature to be varied continuously from room temperature to liquid nitrogen.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 15, 1963
- Accession Number
- AD0409472
Entities
People
- R. D. Andrews Jr.
Organizations
- Massachusetts Institute of Technology