Polyurethane coatings with reduced flammability based on phosphorus-containing polyols | Poliuretāna pārklājumi ar samazinātu degamību uz fosforu saturošu poliolu bāzes

English. To decrease the flammability of bio-based polyurethane (PU) coatings, phosphorus-containing polyols from rapeseed and linseed oils were synthesized. Synthesizing polyols, the seed oil was firstly epoxidized using hydrogen peroxide (H2O2), formic (HCOOH) or acetic (CH3COOH) acids and a catalyst, and then phosphorylated with phosphoric acid (H3PO4). Varying molar ratios of the oil (unsaturated bonds) to H2O2 and HCOOH, synthesis conditions were established, at which epoxidized rapeseed oil with the maximum epoxy value (15.2%) was obtained. The epoxidized rapeseed oil was phosphorylated with different amounts of phosphoric acid (H3PO4) (1, 2, 3 and 5%). After the neutralization and washing, polyols were distilled using a vacuum rotary evaporator. Based on rapeseed oil phosphate polyols, PU coatings were prepared and their properties were studied. The properties of PU coatings were investigated using the tensile test according to ASTM D 882-10, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) using TGA/SDTA 851e and DSC 851e Mettler Toledo. The fire behaviour of wood samples with PU coatings was studied using a FTT Cone Calorimeter (Fire Testing Technology Ltd.). Testing was performed according to ISO 5660-1:2015 at a heat flux of 35 kW/m2. The effect of phosphate groups on the flammability of coatings based on rapeseed oil phosphate polyols was not so pronounced. To achieve a potentially greater effect, the linseed oil (LO), the iodine value of which is higher than that of rapeseed oil, was used in subsequent studies.

Latvian. Lai samazinātu poliuretānu pārklājumu degamību, izpētīta un izstrādāta metodika fosfātu grupu saturošu poliolu sintēzei no rapšu un lineļļas. Fosfātu grupu klātbūtne poliolā ir apstiprināta ar IS un 31P KMR spektru datiem. No sintezētajiem polioliem izgatavoti poliuretānu pārklājumi. Pārklājumu raksturošanai izmantoti stiepes mehāniskie testi, termogravimetriskā analīze, diferenciāli skanējošā kalorimetrija un koniskā kalorimetra testi. Salīdzinot mehāniskās, termiskās un degamības īpašības poliuretānu pārklājumiem no polioliem, kas tika iegūti pie dažādiem sintēžu parametriem, konstatēts, ka, pateicoties fosfātu triestera un pirofosfāta monoestera klātbūtnei, pārklājumiem uz lineļļas poliola bāzes ir labāki raksturojumi, ja fosforilēšana ar H3PO4 notiek izopropanola kā šķīdinātāja klātbūtnē (IPA polioli). Izpētīta tipiska uzbriestošo antipirēnu ietekme uz fosfātu grupu saturošo poliuretānu pārklājumu īpašībām. Noteikts, ka vislielāko poliuretānu pārklājumu degamības samazināšanu var sasniegt, izmantojot kā papildu antipirēnu izpletošo grafītu EG-290. Amonija polifosfāta un melamīna ietekme uz fosfātu grupu saturošo poliuretāna pārklājumu degamību ir krietni mazāka.