Synthesis, cure analysis, and composite properties of allylated cyclopentadiene resins

Abstract

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 -750 J / g with a peak energy a t 3 10°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 a t 180 and 200°C. An increase in viscosity with time was found in each case with gelation occurring a t -15 h and 3 h, respectively. ACP resin was also cured using various concentrations of peroxide and BF, 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.

Gemcitabine and paclitaxel every 2 weeks in patients with previously untreated urothelial carcinoma

“…This decrease was attributed to the lower content of the allylic end groups in longer chains. Thus, the polymerization of allylic group was observed at around 280 °C, which is in accordance with the reported curing temperatures of allylic resins 45, 46…”

High‐Performance Polybenzoxazine Nanocomposites Containing Multifunctional POSS Cores Presenting Vinyl‐Terminated Benzoxazine Groups

“…180 °C with an exotherm peak at 234 °C; the apparent onset of the second exotherm was at 245 °C with an exotherm maximum at 270 °C, when heating at a rate of 10 °C · min −1 10. The two exotherms are responsible for both allyl and benzoxazine polymerization 8, 60, 61. The total exotherm for pure VBa‐POSS was 142.6 J · g −1 , lower than that for pure VBa (423.2 J · g −1 ); the exothermal peak of VBa‐POSS (260 °C) was positioned at a higher temperature than that of pure VBa (207 °C) because of the dilution effect of the POSS units, which inhibited the thermal curing of VBa 2, 8.…”