Use of Dicyclopentadiene and Methyl Dicyclopentadiene for the Synthesis of Unsaturated Polyester Resins.

Dicyclopentadiene (DCPD) modified unsaturated polyester resins (UPRs) are mostly used for hulls, decks, and bathroom facilities. Main advantages of these polymers over orthophthalic or isophthalic polyesters are their relatively low shrinking, reduced styrene emission, lower cost, and fast curing in thin layers. On the other hand, once cured, these materials are more brittle and have lower glass transition temperatures and lower chemical resistance due to their different chemical constitutions.

Crystallization of hollow mesoporous silica nanoparticles.

Complex 3D macrostructured nanoparticles are transformed from amorphous silica into pure polycrystalline α-quartz using catalytic quantities of alkaline earth metals as devitrifying agent. Walls as thin as 10 nm could be crystallized without losing the architecture of the particles. The roles of cation size and the mol% of the incorporated devitrifying agent in crystallization behavior are studied, with Mg(2+), Ca(2+), Sr(2+) and Ba(2+) all producing pure α-quartz under certain conditions.