Production and Dynamic Mechanical Analysis of Macro-Scale Functionalized Polydicyclopentadiene Objects Facilitated by Rational Synthesis and Reaction Injection Molding

Abstract

is a ring-opening metathesis polymer derived from dicyclopentadiene. Valued for its light weight, excellent material strength, and good performance at both high and low temperatures, PDCPD is used to make body panels for tractors and heavy-duty trucks. We recently described the first functionalized form of PDCPD (fPDCPD) that maintains the thermal stability of the parent polymer. However, while commercial PDCPD components are produced through a reaction injection molding process on very large scale, our fPDCPD polymer was developed on small scale, and has not been shown to be a viable substrate for reaction injection molding processes. Here we address these limitations by providing an improved synthesis of the fDCPD monomer mixture on half-kilo scale, and describing a method for separating the polymerizeable monomer from other, nonpolymerizeable, regioisomers without chromatography. We further demonstrate a reaction injection molding process for the creation of prototype fPDCPD components. Together, these increases in scale and advances in small object manufacturing facilitate the production of regular-dimensioned samples for dynamic mechanical analysis, permitting the first direct comparison of the mechanical properties of Clinked ester-functionalized PDCPD with those of unmodified PDCPD. Additionally, by employing monomers of different regioisomer purity, products are achieved encompassing a broad range of glass transition temperatures and storage/loss moduli.

Molecularly Designed Additives for Chemically Deconstructable Thermosets without Compromised Thermomechanical Properties

“…30 mol %) . Other reports have noted similar increases in T g with increased crosslinking density or polar functionalization of DCPD itself. − The addition of cleavable crosslinks to thermosets with permanent, noncleavable crosslinks, however, cannot facilitate chemical deconstruction into soluble products (Figure C) . Thus, additives that simultaneously enable thermoset deconstruction without compromising mechanical properties are elusive.…”

Harnessing the surface chemistry of methyl ester functionalized polydicyclopentadiene and exploring surface bioactivity

“…Understanding the chemical properties of a novel material is paramount to discovering its possible future applications. Although some of the unique properties of f PDCPD have been reported previously by our group, [18][19][20] the degree to which the surface can be further functionalized is not yet completely understood. For example, while previous work has shown that partial hydrolysis of the ester functional groups on the surface of f PDCPD can raise the surface energy, 18 we have not yet examined the installation of other functionality at this position.…”

“…21 f PDCPD offers a tunable, elevated surface energy, and a higher T g compared with the parent material. 18 Importantly, both the thermal stability of f PDCPD (as assessed by thermogravimetric analysis) 18,19 and the storage modulus (measured by dynamic mechanical analysis) 20 were shown to be similar to those of the parent polymer. The introduction of new functionality while maintaining durability allows for further modifications, potentially increasing the applications of f PDCPD for industrial and biomedical use.…”

“…Ester-functionalized monomer 1 was prepared as described previously. 20 2nd Generation Grubbs catalyst was purchased from Chem-Impex. RGD and RAD cyclic peptides were purchased from Peptides International.…”

“…17 To address the low surface energy of PDCPD, and to bestow additional function to the polymer, we installed a C-linked ester group on the dicyclopentadiene monomer. [18][19][20] The esterfunctionalized monomer ( f DCPD) engages in Ru-catalyzed ROMP similarly to the parent dicyclopentadiene, to afford a linear telechelic polymer that can then be thermally cured to provide a densely crosslinked, functionalized form of polydicyclopentadiene that we call f PDCPD (Fig. 1).…”