Uticaj usporivača gorenja na svojstva furnira i slojevitih ploča od bukovog i topolovog drveta

Abstract

Poslednjih desetak godina, u skladu sa novim standardima i propisima, znatno povećana je potreba za vatrootpornim drvenim konstrukcijama i elementima. S druge strane, evidentan je nedostatak detaljnih istraživanja interakcije između drvnih vrsta, posebno domaćih i izabranih, čak i osnovnih vatrootpornih hemikalija. U ovom istraživanju, bukovi i topolovi furniri su različito vreme impregnisani potapanjem u 25% rastvor monoamoonijum-fosfata (MP) i natrijum-acetata (SA). U cilju preliminarnog određivanja postignute vatrootpornosti u furnirima, pre izrade gotove furnirske ploče, sprovedene su dinamičke metode termalne analize i to: termogravimetrijska (TG) analiza i derivativna termogravimetrijska (DTG) analiza impregniranog i neimpregnisanog drveta kao i samih vatrootpornih sredstava. Za impregnisane i neimpregnisane furnire su takođe određene i sledeće karakteristike absorpcija impregnacionog rastvora (A), maseni procentualni prinos vatrootpornih sredstava (WPG), ravnotežna vlaga (EMC), pH vrednost, a za furnirske ploče još i smicajna čvrstoća i vatrootpornost. Vatroootpornost furnirskih ploča je testirana prema JUS standardu i kao efikasniji se pokazao monoamonijum-fosfat što su pokazale i TG/DTG analize iz čega se može zaključiti da TG metode imaju značajnu ulogu u predviđanju vatrootpornosti budućeg proizvoda.

Rising demands for fire resistance properties of wood construction and elements matching new standards have been an important part of building codes during the last decade. On the other side, lack of more detailed research on interaction between wood species and selected fire retardant chemicals even with basically one is evident. This is particularly truth with domestic wood species. In this research, beech and poplar veneers were immersed in 25% solutions of monoammonium phosphate (MP) and sodium acetate (SA) and impregnated for different periods of time. To determine the preliminary level of fire retardancy achieved in veneers before manufacturing of finished plywood, thermo gravimetric (TG) and derivative thermo gravimetric (DTG) methods were used. TG and DTG analyses of treated and untreated wood, as well as of fire retardants alone, were performed. The next properties of impregnated and no impregnated veneers and plywood were determined: absorption of imp regnant solution (A), weight percent gain (WPG) of imp regnant, equilibrium moisture content (EMC), pH values, and in the case of plywood, strength and fire resistance. Fire resistance of plywood was tested in accordance with standard test for resistance to the effects of fire and the most efficient fire retardant, monoammonium phosphate, had the same result as TG/DTG analyses, which pointed out the validity of TG methods in predicting fire resistance of future products.