Hi everyone. First of all, thanks for your attention. I have compounded a polymer based to produce some EVA-based foams with more than 1500 % volume change. The results are perfect in small batch sizes (3 Kg), but when we scale up to 300 Kg, the results are not repeated. it seems the foam cells are collapsed. this compound includes azodicarbonamide as a blowing agent and DCP peroxide as a curing agent, (I also use antioxidants). Has anybody experienced a similar problem? Thanks for sharing your comments.
There is a possibility the antioxidants are consuming the peroxide, leading to slow or poor state of cure causing collapse. The rates of peroxide decomposition, crosslinking, reaction with antioxidants and blowing will all be temperature dependent, so trying different cure temperatures could be worthwhile, otherwise select an antioxidant that will not interfere with the peroxide cure.