Vol.2, No 4, 2004 pp. 243 - 250
UDC 66.097.3
CATALYSIS OF THE ISOCYANATE-HIDROXYL REACTION
BY NON-TIN CATALYSTS IN WATER BORNE
TWO COMPONENT POLYURETHANE COATINGS
Jakov Stamenković1, Suzana Cakić1*,
Sandra Konstantinović1, Sonja Stoilković2
1University of Niš, Faculty of Technology, Leskovac
Bulevar oslobodjenja 124, 16000 Leskovac, Serbia and Montenegro
2DP Pomoravlje, Niš
* e-mail: suza967@yahoo.com
Abstract. Because of the high toxicity of some organotin compounds, there has been an attempt to ban organotin compounds from all coating applications. Organotin catalysts are not selective. They catalyze the reaction of isocyanates with hydroxyl groups from polyol and water and the hydrolysis of ester groups.
One novel approach to control the water side reaction is the use of catalysts which selectively catalyze mentioned reaction.
In this paper, the impact of catalysts selectivity of Mn(III) complexes with mixed ligands, selective zirconium catalyst K-KAT 6212 and DBTDL on mechanical properties of water-borne two component polyurethane coatings was investigated, by using an FTIR method.
Much better performances can be achieved, using more selective catalyst. The performance is similar to those based on organic solvents, but with less content of volatile organic solvents (VOC).
Key Words: Ccrosslinking, Waterborne Two Component Polyurethanes,
Selective Catalyst, König Hardness
SELEKTIVNA KATALIZA IZOCIJANAT-HIDROKSILNE REAKCIJE POMOĆU NEKALAJNIH KATALIZATORA
U VODENIM DVOKOMPONENTNIM POLIURETANSKIM PREMAZIMA
Zbog visoke toksičnosti u svetu postoji veliko interesovanje za zamenom organo kalajnih jedinjenja u premazima. Uz to, organokalajni katalizatori nisu selektivni. Oni katalizuju reakciju izocijanata sa hidroksilnim grupama i iz poliola i iz vode, kao i hidrolizu estarske grupe.
Nov pristup, bi bio u je korišćenju jedinjenja koja selektivno katalizuju navedene reakcije.
U radu je ispitivan uticaj selektivnosti katalizatora na bazi Mn(III)kompleksa sa mešovitim ligandima, selektivnog katalizatora cirkonijuma, K-KAT?XC-6212, kao i DBTDL, na mehaničke osobine vodenih dvokomponentnih poliuretanskih premaza, korišćenjem FTIR spektroskopije.
Izborom selektivnijeg katalizatora mogu se postići znatno bolje performanse, slične onima na bazi organskih rastvarača ali sa daleko manjim sadržajem isparljivih organskih rastvarača (VOC)..