The annual cost to repair, replace, or maintain service vehicles and buildings with water damage runs into the tens of billions. Water damage, ranging from extremes like corrosion-induced mechanical failure to something as benign as water stains, creates problems that the Navy and industry have to deal with on a daily basis. Since water is ubiquitous and largely unavoidable, measures must be taken to extend the lifespan of service vehicles and buildings in order to minimize maintenance and replacement costs.
Saccate pollen grains having one, two, or rarely three air sacs attached to a central body are known to be extremely hydrophobic. In fact, they are often sold in scientific supply shops as a way to demonstrate hydrophobicity. Anyone who has handled these materials knows that they are what is commonly termed unwettable. Navy researchers have developed a polymer – PB2 – that behaves very similarly to saccate pollen grains, with the one advantage that, as a polymer, it can be made into a coating useable alone or as a drop-in additive to existing polymers.
PB2 is the condensation product of the reaction between a perylene-derived monomer and a bisphenol-derived monomer. The condensation reaction is carried out in standard dehydrating conditions using a dehydrating acid and heat. The Navy-developed procedure sustains the condensation reaction at elevated temperatures until polymers of desired molecular weight are achieved. PB2 does not require any post-application thermal cures and is readily soluble in common organic solvents, such as THF, chloroform, and chlorobenzene. Its water-resistant properties are very similar to saccate pollen grains. After a week in a water Soxhlet extractor (in constant contact with hot water), the material remained a dry powder.
- The polymer forms very homogenous uniform films with ultra-smooth surfaces
- US patent 9,670,317 available for license
- Potential for collaboration with Navy researchers