Synthesis, cure analysis, and composite properties of allylated cyclopentadiene resins
Polymers and High Performance Materials
Allylated cyclopentadiene was synthesized through the phase transfer reaction of cyclopentadiene and allyl chloride in the presence of a strong base. The reaction yielded a mixture of isomers with 2 to 6 allyl groups per cyclopentadiene ring. Variations in reactant ratios changed product ratios only slightly; however, lower ratios of allyl chloride to cyclopentadiene (4:1 and 2:1) produced lower substituted products. DSC analysis of the ACP showed thermal cure without added catalyst. The total enthalpy of cure was similar to 750 J/g with a peak energy at 310 degrees C. FTIR analysis of the thermal cure showed the predominate cure mechanisms to be ene reactions and polyadditions of allyl groups with a small amount of oxidation. Partial curing (B-staging) of ACP was conducted thermally at 180 and 200 degrees C. An increase in viscosity with time was found in each case with gelation occurring at similar to 15 h and 3 h, respectively. ACP resin was also cured using various concentrations of peroxide and BF3 dibutyl etherate catalysts. In all cases gelled materials were formed. ACP/carbon fiber and ACP/glass fiber composites gave flexural moduli of 165 and 42 GPa, respectively. Flexural strength values were found to be 956 MPa for ACP/carbon and 681 MPa for ACP/glass. Treatment of ACP/carbon fiber composites in boiling water or refluxing toluene had no significant effect on their mechanical properties.
Mathias, L. J.,
(1997). Synthesis, cure analysis, and composite properties of allylated cyclopentadiene resins. POLYMER COMPOSITES, 18(4), 509-517.
Available at: http://aquila.usm.edu/fac_pubs/5395