Gj. Tregre et Lj. Mathias, Synthesis, characterization, and cure of propargyl-functionalized cyclopentadiene for use in carbon-carbon composites, CHEM MATER, 11(3), 1999, pp. 698-703
A new composite resin was synthesized by reaction of cyclopentadiene with p
ropargyl bromide and base under phase transfer conditions to give a mixture
of products with two to six propargyl functionalities per cyclopentadiene
ring. DSC analysis of the propargylated cyclopentadiene resin (PCP) showed
thermal cure with no added initiator over a broad temperature range with a
peak at 250 degrees C. FT-IR analysis of the cured resin showed the generat
ion of new unsaturated and saturated species through a hydrogen transfer en
e-like reaction and polyaddition of the propargyl groups to give oligomers
and/or cyclotrimers. X-ray analysis showed no long-range graphitic order, N
eat PCP resin cured at 250 degrees C gave a room temperature flexural modul
us of 2.9-3.0 GPa by DMA and showed no thermal transitions up to 300 degree
s C while PCP/carbon fiber composites gave a room-temperature flexural modu
lus of 115-120 GPa and a flexural strength of approximately 950 MPa, TGA sh
owed exceptional carbon yield at 1000 degrees C with 75% weight retention i
n both air and N-2, while composites with 40 wt % resin showed 90% carbon y
ield. Interlaminar shear strengths of carbonized samples were comparable to
those of presently used materials.