A detailed review of the concept of “maximum incremental reactivity”highlighted the recent semi-annual technical conference of PRA Laboratories Inc.

YPSILANTI, MI — A detailed review of the concept of “maximum incremental reactivity” (MIR), a system of assessing the relative tendency of various solvents to contribute to ground-level ozone pollution, highlighted the recent semi-annual technical conference of PRA Laboratories Inc. PRA Labs is a technical organization of coatings-manufacturing companies.

William Carter, a professor at the University of California-Riverside and a noted expert on the topic of relative reactivity of VOCs, was the featured speaker at the conference. Carter reviewed the MIR approach, which has been incorporated into an aerosol-coatings regulation enacted by the California Air Resources Board (CARB). The agency also is considering the use of relative-reactivity data in the development of future VOC regulations on architectural and industrial maintenance coatings.

The aerosol-coatings regulation is being described as a “win-win” situation, in that it provides greater formulating latitude while reducing emissions of more highly reactive VOCs – compounds that react more readily with nitrogen oxides to form ozone pollution.

The PRA technical conference also featured updates on the following.

• Non-isocyanate approaches to urethane performance, including ambient-cure capabilities of cyclic carbonate chemistry;

• Comparative testing and compositional analysis of commercial urethane topcoats;

• Development of direct-to-metal (DTM) latex paints;

• Comparative testing of exterior latex flat paints;

• The optimal use of TiO₂ spacers; and

• Exterior exposure versus accelerated weathering of semi-transparent latex stains.