in many processes polymeric foams can be produced by using chemical or physical blowing agents. in this work for polyethylene foam production, the chemical blowing agents and compression moulding process were employed. at first, by using dsc diagram of two polyethylene grades, a suitable polyethylene grade was selected for foam production and then we discuss about blowing agent critical percent...

BANYAY, GREGORY ALLEN, M.S., June 2006, Mechanical Engineering EXAMINATION OF POLYMERIC FOAM AS AN ON-BOARD VEHICULAR HPR HYDROGEN STORAGE MEDIA (113 pp.) Director of Thesis: Bhavin V. Mehta One of the major hurdles to be traversed before a Hydrogen Economy becomes practical, and therefore abundant, is the problem of its storage. An ideal HPR pressure vessel exhibits uniformly sized, spherical ...

This paper has investigated the impact testing method on the polymeric foams using digital image correlation. Accurate average stress-strain relations can be obtained when soft large diameter polymeric pressure bars and appropriate data processing are used. However, as there is generally no homogeneous strain and stress fields for polymeric foam, an optical displacement field observation is ess...

The intricate structure of polymeric foams may be examined using 3D imaging techniques such as MRI or X-ray tomography followed by image processing. Using a new 3D image processing technique, six images of polyurethane foams were analyzed to create computerized 3D models of the samples. Measurements on these models yielded distributions of many microstructural features, including strut length a...

A post-growth chemical vapor deposition (CVD) treatment was used to tune the compressive mechanical properties of carbon nanotube (CNT) arrays. Millimeter tall CNT arrays with low compressive resilience were changed to a foam-like material with high compressive strength and almost complete recovery upon unloading. The foam was tuned to provide a range of compressive properties for various appli...

A variety of materials require functionally graded cellular microstructures whose porosity is engineered to meet specific applications (e.g. mimic bone structure for orthopaedic applications; fulfil mechanical, thermal or acoustic constraints in structural foamed components, etc.). Although a huge variety of foams can be manufactured with homogenous porosity, there are no generic processes for ...

Flexible Polyurethane (PU) foam samples with different densities and chemical formulations were tested in quasi-static stress-strain compression tests. The compression tests were performed using the Lloyd LR5K Plus instrument at fixed compression strain rate of 0.033 s-1 and samples were compressed up to 70% compression strains. All foam samples were tested in the foam rise direction and their ...

Tubular ceramic foams were prepared by using natural clay as starting material and 120 ppi polyurethane foam as template via polymeric sponge method. Samples were sintered with different temperatures from 1200°C to 1280°C. The result shows that 1250°C is the ideal sintering temperature where the highest compressive strength of 1.980MPa at 47.31% porosity is obtained. The highest value in compre...

A self-healing microvascular polymeric foam has been developed to improve the resilience of rigid foam core materials for sandwich structures. We investigated the healing of brittle polyisocyanurate (PIR) foam after mode-I crack separation in a 3-point single edge notch bend (SENB) specimen. A two-part healing chemistry based on a commercially available polyurethane (PUR) foam formulation is em...