BASF has announced that, through a German government-supported joint research project with glass maker Interpane and house builder Sto, it is developing temperature-sensitive polymers. BASF says produ…
BASF has announced that, through a German government-supported joint research project with glass maker Interpane and house builder Sto, it is developing temperature-sensitive polymers. BASF says products should reach the market within two to three years. The products are polymer blends that change from transparent to cloudy at specific temperatures. The clouding temperature can be set from 20C-100C, BASF says, so the polymer blends can be used to coat windows and glass roofs, replacing mechanical shades, and on industrial equipment at risk for overheating. BASF says tests show the polymers remain temperature sensitive for a few months. It says that performance must improve to 10 years before the polymers reach the marketplace. The clouding takes place when, at a certain temperature, dense regions form in the material and scatter light. The size of the region can be adjusted to control how cloudy the material gets. The regions form when the two polymers are heated and become incompatible, separating into two phases. When the material cools, it becomes clear again. BASF says it adjusts the compatibility of mixtures by varying polymer structures. With hydrogels, cross-linked polymers able to retain water, BASF mixes in a second water-soluble polymer. At certain temperatures, the second polymer starts to precipitate out, which turns the material cloudy.