Green rigid polyurethane foam from hydroxyl liquid natural rubbers as macro-hydroxyl polyols

Abstract

The novel renewable source precursors from hydroxyl liquid natural rubbers (HLNRs) with various secondary hydroxyl content of 22% (HLNR22), 35% (HLNR35), and 50% (HLNR50) (or naming macro-hydroxyl polyols) were used to prepare rigid polyurethane foam. The aim of this study was to investigate the effect of hydroxyl content of HLNR precursors and the ratio of HLNRs and commercial polyols on physico-mechanical properties of rigid polyurethane foams in comparison to foams made from commercial polyols. The increase in hydroxyl content of HLNRs resulted in the foams with larger cell size while the increase in the HLNR portion caused a small and more uniform cell size, which is related to their density and compressive strength. Thermal stability of polyurethane foams was analyzed by thermogravimetric analysis and the results have demonstrated that the use of HLNR polyols improved thermal stability of polyurethane foams in comparison to commercial foam.

Sago starch and esterified sago starch as eco-friendly fillers for rigid polyurethane foams

“…The other signals are due to the polyurethane-amide linkage at 1597 cm −1 (in plane N-H bending of amides), 1230 cm −1 (C-N stretching, N-H bending of amides). 30–32 These features provide evidence that hydroxyl groups on sago starch and esterified sago starch reacted with the isocyanate groups from p-MDI.…”

Polyurethane foams co-blown by water and alkylated polyethylenimine-CO2 adducts: An additive or antagonistic effect?

“…It has been used as a chemical blowing agent since the innovation of PU foams in the 1940s. 15,16 It is very cheap, and most importantly, it is climate neutral. However, overdosing with water would generate too many urea linkages in the PU polymers, thereby embrittling the resultant foams and decreasing their interfacial adhesion.…”