ABSTRACT The addition of expanded graphite (EG) on environmentally friendly polymer matrix was systematically studied to produce carbon-polymer porous composite. Firstly, an appropriate EG was produced by monitoring the time and temperature of intercalated graphite thermal expansion while poly(furfuryl alcohol) (PFA) resin was obtained from the furfuryl alcohol polymerization. After PFA synthesis, different EG amounts of 0.2, 0.5, and 1.0 wt% were added in the resin and evaluated by viscosimetry and differential scanning calorimetry that showed EG helped in the crosslink formations decreasing the onset and endset temperatures. PFA resin kept a good fluidity, even for 1.0 wt% EG ensuring its homogeneous impregnation on the polyurethane foams. FTIR analyses confirmed the presence of functional groups on EG, which would contribute to the resin impregnation on the foam porous structure without changing the thermal resistance of the final product.

Abstract In this study, the chemical interaction between functionalized carbon nanotuboes with carboxyl groups (CNT-f) and the subsequent addition of furfuryl alcohol (FA) and mixture with poly(furfuryl alcohol) (PFA) resin was evaluated. The FA with CNT-f was mixed in PFA resin to facilitate the chemical interaction of CNTs. The morphological and chemical interaction were studied by Transmission Electron Microcopies (MET), FTIR analyses, Raman Spectroscopy, viscosimetry and X-ray photoelectron spectroscopy (XPS). It was observed that a chemical interaction occurs through the opening of the hydroxyl polymer chain with a subsequent output of one water molecule. This interaction was evident from the FTIR and XPS data of the PFA composites. In this way, the mixture of functionalized carbon nanotubes with carboxyl groups in the FA, before adding this reinforcement into the PFA resin, can be considered a good procedure in order to obtain an appropriate chemical interaction between the CNT and PFA resin.

In this work, polyarylacetylene (PAA) prepolymer obtained from 1,4-diethynylbenzene was evaluated as polymeric precursor of monolithic vitreous carbon (MVC). The monomer 1,4-diethynylbenzene was synthesized and the PAA prepolymer was prepared with 13, 16 and 19 wt % of nickel catalyst. The best percentage of nickel catalyst considered was 13 wt %, due to the lower molecular weight and polydispersity index and higher carbon yield. The traditional production of MVC is obtained from phenolic and poly(furfuryl alcohol) resins, which require many hours to pyrolyze due to the large quantity of gases generated. Furthermore, the porosity is hard to control using these conventional resins. Polyarylacetylene releases little volatiles due to the polyaddition reaction and the aromatic rings in PAA chain also provide a high thermal stability, therefore the heat treatment could be faster without cracking the carbon material. This would also lower the cost of fabrication of MVC, in addition to the low porosity observed, making this polymer a good matrix for MVC.