It would be convenient to use a temperature adjustable heat plate (element)/mug warmer for the massive amount of blender bottles accumulated over the years.
What are safe thresholds to safely warm the contents in seemingly, relatively safe plastic containers, BPA- and Phthalate-free, without leaching chemicals into the contents. Is plastic even a safe or effective, heat conductor long term?
It seems the type pf plastic they use is made with High-density polyethylene (HDPE) & Polypropylene (PP). The melting point of HDPE and PP is respectively 267.44°F and 340°F. High-density polyethylene is a relatively poor heat conductor with a value of .42-.51. Porcelain and better yet Stainless steel have much higher thermal conductivity values, 1.40-2.27 and 16.3-24 respectively.
Not sure if this is a more suitable question for the other stack sites (i.e. Coffee, Seasoned Advice or Physics), it seems most aligned with a chemical/materials engineer.