Bio-based flexible polyurethane foam synthesized from palm oil and natural rubber

As environment friendly polymers are required to reduce the green-house gas emissions and global warming, bio-based polyurethane foam (PUF) is attracting interest from the industrial sector and researchers. Bio-based polyols for PUF have been synthesized from various renewable resources, mostly plant oils. The present study explored a novel bio-based PUF produced from a mixture of bio-based polyols synthesized from palm oil and natural rubber. Palm oil-based polyol (POP) was synthesized via an epoxidation reaction of double bonds of palm oil followed by complete oxirane ring-opening. Hydroxy telechelic natural rubber (HTNR) was synthesized by oxidative degradation using periodic acid and sodium borohydride. For comparison, two diisocyanates were used: toluene-2,4-diisocyanate and polymeric methylene diphenyl diisocyanate. POP and HTNR were miscible and all PUFs showed polyhedral semi-closed cells and hardness was in the flexible foam range. One possible application of the novel PUF could be thermal insulation.