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This study is dedicated to the investigation of the change in mechanical properties of rigid polyurethane foam reinforced with carbon nanoparticles. Pure and nano-reinforced polyurethane foams were produced by an in situ polymerization technique. Carbon nanotubes (single-walled carbon nanotubes and multi-walled carbon nanotubes) and carbon nanofibers were used as reinforcing particles. Diphenylmethane 4,4'-diisocyanate treatment of carbon nanoparticles was performed in order to improve the interaction of nanoparticles and polymer matrix. The alterations of morphology and mechanical properties of the nano-reinforced polyurethane foam were studied by varying the amount of both pristine and modified carbon nanoparticles. Compression tests revealed an improvement of both compressive Young’s modulus and compressive strength, and scanning electron microscope observations showed a decrease of the average cell size of the foam.

The present paper is dedicated to fabrication of microcellular PP-MMT nanocomposite foams blown by CO2 at 3-7 MPa pressure range. XRD and TEM studies showed that MMT particles were well exfoliated upon PP-MMT nanocomposite processing, however presence of the nanoclay particles did not facilitate the foaming process, resulting in non-uniform cell structure and low expansion ratios. SEM images demonstrate that clay nanoparticles have not improved the foam morphology; and no nucleation effect of the clay was observed in the produced foams. These data were supported by DSC studies.

The present work covers the processing route and investigation of PP-MWCNT nanocomposite foams. CO2 is used as a blowing agent in a batch foaming process with a saturation pressure range of 3-7 MPa. Carbon nanotubes act as nucleating agents during the foaming process, which is supported by SEM image analysis and DSC study. Relative density measurements have demonstrated that even though MWCNT promote nucleation of a large amount of cells, the densities of PP-MWCNT nanocomposite foams do not differ significantly from pure PP samples.

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