6.1 Novel Polyol Dispersions with End of Usable Pot-life Indicator
(Room 240-242)
10 Apr 18
9:00 AM
-
9:30 AM
Tracks:
Session 6: Polyurethanes I
New Concepts for High Performance Polyol Dispersions Suitable for 2-pack Coatings with Polyisocyanates
Decreasing VOC emissions of coatings has been a progressive effort for scientists active in the coatings industry. At equal solids content, dispersions generally afford a lower viscosity compared to solutions. Therefore, replacing solvent borne systems with waterborne dispersions is an effective strategy to reduce VOC emissions.
Performance in coatings is strongly coupled to the presence of a thermoset network formed via a crosslinking mechanism. A common approach is combining a solvent borne polyol with a poly isocyanate to form a thermoset coating after application. The urethane network formed this way delivers desired properties such as toughness and chemical resistance. Polyol dispersions offer a significant VOC benefit and can be combined with poly isocyanates in a similar way. Unlike the solventborne systems, polyol dispersions available on the market lack a discernible end of pot-life marker and contain significant hydrophilic moieties that detract from the coating performance.
In this paper, we introduce waterborne dispersions with very clean water phase, free of hydrophilic moieties common in traditional polyol dispersions. Such high-performance dispersions can be formulated to provide both chemical and corrosion resistance with fast property development to fulfil requirements of several applications including demanding usages such as DTM. Furthermore, we describe polyol dispersions with an end of pot-life indication via viscosity increase similar to solvent based systems.