Ilze Beverte1,*, Vairis Shtrauss1, Aldis Kalpinsh1, Uldis Lomanovskis1, Ugis Cabulis2, Irina Sevastyanova2, Sergejs Gaidukovs3
Journal of Renewable Materials, Vol.8, No.9, pp. 1151-1170, 2020, DOI:10.32604/jrm.2020.010215
- 03 August 2020
Abstract Early investigations of dielectric permittivity of rigid polyurethane
foams at low frequencies were made on petrochemical-origin foams, mainly by
means of parallel plate capacitors. In the present investigation biopolyol was
synthesized from Latvia-grown rapeseeds’ oil by the transesterification method
with triethanolamine, in an environmentally friendly process, without emission
of harmful substances, at temperatures 175°C ± 5°C. Rigid, closed-cell rapeseed
oil polyol polyurethane biofoams and petrochemical foams were made ensuring
content of the renewable rapeseed oil polyol in ready foams 27 wt.%–29 wt.%.
Dielectric permittivity of the polyurethane foams and the underlying monolithic
petrochemical-origin polyurethane and… More >