Embodiments include poly(allyl ether)s of polycyclopentadiene polyphenol that can be obtained by allylation of a polycyclopentadiene polyphenol, where the aromatic hydroxyl group(s) (—OH) are converted to HR1C═CR1—CH2—O— and/or H2R1C—CR1═HC—O—, where R1 is as described herein. Embodiments also include thermosettable compositions including the poly(allyl ether)s of polycyclopentadiene polyphenol and products obtained by curing the thermosettable compositions.