Polycyanurate networks from dehydroanethole cyclotrimers: Synthesis and characterization

Novel biobased trisphenols were obtained by palladium- and cobalt-catalyzed [2 + 2 + 2] cycloaddition of dehydroanethole isomers which were readily prepared from the natural product trans-anethole. The trisphenols were transformed into their corresponding tricyanate esters and thermally cured to give polycyanurate networks. Comparison of the thermal properties, from differential scanning calorimetry, thermogravimetric and oscillatory thermomechanical analyses, of the new tricyanate esters with similar commercial products is presented. A new tricyanate ester with an acceptable processing temperature that yields a polycyanurate with very high glass transition temperature and low water absorption was found. Interestingly, the low moisture absorption was found to help limit the degradation of residual cyanate ester groups during exposure to hot water, allowing for a substantial recovery in the glass transition temperature upon subsequent heating, an unusual phenomenon for polycyanurate networks.     

Moving Least Squares Coordinates

We propose a new family of barycentric coordinates that have closed‐forms for arbitrary 2D polygons. These coordinates are easy to compute and have linear precision even for open polygons. Not only do these coordinates have linear precision, but we can create coordinates that reproduce polynomials of a set degree m as long as degree m polynomials are specified along the boundary of the polygon. We also show how to extend these coordinates to interpolate derivatives specified on the boundary.