Bio-based polyurethane-polyisocyanurate composites with an intumescent flame retardant. (May 2016)

• Record Type: Journal Article
• Authors: Kurańska, Maria; Cabulis, Ugis; Auguścik, Monika; Prociak, Aleksander; Ryszkowska, Joanna; Kirpluks, Mikelis
• Is Part Of: Polymer degradation and stability. Volume 127(2016:May)
• Page Start: 11
• Page End: 19
• Publication Date: 2016-05
• Subjects: Rigid polyurethane-polyisocyanurate foams -- Bio-polyols -- Rapeseed oil -- Thermal stability -- Expandable graphite; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2016.02.005
• Languages: English
• ISSNs: 0141-3910

Abstract

Abstract: Rigid polyurethane and polyisocyanurate (PUR-PIR) foams are one of the most effective thermal insulation materials applied in a wide range of industries. A sustainable solution for the production of these materials is to substitute one of their petrochemical components with a component produced from bio-based resources, like vegetable oils. The biggest disadvantage of this type of thermal insulation is its high flammability which usually is reduced by an addition of halogen-based flame retardants. Halogenated flame retardants are getting out of use due to potential health risks. Two different bio-based polyols obtained from rapeseed oil were applied to develop rigid PUR-PIR foams with isocyanate indices of 150 and 250. Flammability of these materials was decreased using an intumescent expandable graphite (EG) filler; 0%; 3%; 6% and 9% contents of EG were used. Flammability (Cone calorimeter), combustion (limited oxygen index, thermal imaging), thermal stability (TGA/DTG) were studied for the developed PUR-PIR foams. The addition of EG did not change the ignition behaviour of the developed materials but it had a significant influence on other flammability properties. Due to the development of a stable char layer, the peak value of the heat release in the Cone Calorimeter test was reduced from 240 to 136 kW/m 2, the released smoke was also reduced from 560 to 288 m 2 /m 2 . TGA graphs showed a significant char formation (sample with 9% of EG) that was stable at high temperatures, over 400 °C. The addition of EG to the PUR-PIR system had a positive effect on the burning process which was confirmed by thermal imaging camera results. The formation of the char layer moderated the combustion of the PUR-PIR foams and increased the burning time.