I have not any luck elsewhere. I am sure there are some experts that frequent this newsgroup that perhaps could assist.
I purchased some quarter inch thick plastic sheet from a surplus store. They had it labeled as polystyrene, but I wouldn't trust that. I'm trying to identify it and am having difficulty.
I have gone through identification charts such as one at
It is a thermoplastic. I put a sample in boiling water. At that temperature it just begins soften slightly and can be bent slightly with fingers.
It floats but does not flame like PE or PP is described in the chart, so I hesitate to call it either. Expanded polystyrene also floats but would lead down the wrong path in the chart, so I'm not sure this is a good test.
When subjected to a butane torch there is an orange flame. The material itself never flames or drips. While exposed to the butane flame there is a dense black smoke with an odor perhaps like diesel. It just smells like typical burning plastic to me. Not acidic or rancid, etc.
After being exposed to flame, the burned material is charcoal like, crumbly and leaves a black soot like substance on hands.
It cuts nicely with a table saw as that is how I cut samples.
I tried ABS cement (MEK) and it stuck pieces together enough that they didn't fall apart but a firm pull separated them. There was no welding or fusing of the pieces.
Ultimately I would like to know what this is so I can determine if there is a good adhesive or if I need to use fasteners. Also knowing what it is and its properties helps determine what projects it can be used for.
Any assistance is greatly appreciated. Thanks.