A Single-Atom Upgrade to Polydicyclopentadiene

Abstract

Chemical cross-links within polymers increase mechanical strength and rigidity. Such cross-links can be either irreversible (e.g., those derived from carbon–carbon bonds) or reversible (e.g., those that depend on X–H···O hydrogen bonds). Here we describe a ketone-functionalized derivative of polydicyclopentadiene that establishes an unprecedented network of vinyl C–H···O hydrogen bonds within the polymer. The resulting thermoset displays a significantly increased glass transition temperature relative to the unfunctionalized polymer, together with enhancements to storage modulus, Young’s modulus, and compression strength.

Efficient Oxidation with Singlet Oxygen from 5,10,15,20-Tetraphenylporphyrin under Blue LED Irradiation and Air Atmosphere: Simplified Preparation of Key Building Blocks for Natural Product Synthesis

“…In 2023, DiLabio, Wulff, and co-workers reported the allylic oxidation of dicyclopentadiene (1) under an air atmosphere (Scheme 2C). 16 However, these reaction conditions involved a very long time (27 days). Inspired by these reports, we aimed to develop reaction conditions suitable for the oxidation of dicyclopentadiene (1) and cyclopentadiene (7).…”

“…First, we optimized the reaction conditions for the allylic oxidation of dicyclopentadiene ( 1 ) (Table 1 ). We screened a series of lamps for this reaction (entries 1–4) and found that under halogen lamp 16 irradiation, the desired enone 2 was obtained in 13% yield (entry 1). We examined the use of a fluorescence lamp 14 in this oxidation and the resulting enone 2 was obtained in 25% yield (entry 2).…”

“…We screened lamps for this reaction (entries 1-4). Under halogen lamp 16 irradiation, the desired enone 2 was obtained in a 13% yield (entry 1). In entry 2, we attempted to use a fluorescence lamp 14 in this oxidation, resulting in enone 2 in a 25% yield.…”

High‐Performance Low‐kPoly(dicyclopentadiene) Nanocomposites as Achieved via Reactive Blending with Norbornene‐Functionalized Larger POSS

“…[12,13] Nevertheless, its further application is restricted by the modest glass transition temperature (T g ≈ 130 °C), high coefficient of thermal expansion (CTE, up to 140 ppm °C−1 ), and relatively high k value. [14][15][16] Although the functionalization of DCPD monomers, [16,17] regulation of the catalyst loading, [18,19] and addition of norbornene-based cross-linkable co-monomers [14,20] have been shown to enhance the thermal and mechanical properties of PDCPD, the higher polarization of these monomers and comonomers, along with higher catalyst loading are usually unfavorable to improve the dielectric properties. In general, both decreasing the molecular polarization and introducing air pores (k air ≈ 1) are effective strategies for reducing material's k value.…”