An experimental investigation is performed to characterize the effect of carbon nanotubes on the average mechanical properties of polyurethane foams. Polyurethane foams are doped with as-grown and oxidized carbon nanotubes at varying carbon nanotube concentrations. It is observed that the inclusion of carbon nanotubes up to a threshold concentration decreases the density of freely expanding polyurethane

In the present study, two-step foaming procedure with a designed in-situ foaming observation apparatus was used to study the foaming dynamics of styrene-methyl methacrylate (St-MMA) copolymer/nanosilica composites. For this purpose, the St-MMA copolymer was synthesized using suspension copolymerization and its nanocomposites were prepared using solution method. The foaming dynamics was studied through

Addition of fillers in polyurethane foams enhances the mechanical properties of polymeric foams. However, fillers can be loaded to a certain extent, as higher percentage of fillers in polymeric foam causes structural instability leading to the collapse of foam. In this article, we report the use of hollow glass microspheres as a possible co-filler which enables higher loading of nano-clay in flexible

The objective of this study was to produce a polyol from spent coffee grounds via acid liquification process that meets performance requirements for use in polyurethane applications. The spent coffee grounds based polyol was characterized and evaluated on a fully catalyzed model rigid polyurethane foam system. The pH of the polyol was 6.8, acid value 4.12 mg KOH/g, and hydroxyl value 302.6 mg KOH/g

Two ester-based and one ether-based thermoplastic polyurethane grades have been used to produce thermoplastic polyurethane foams. The foaming process comprised pressure-induced batch foaming, foam extrusion, and bead foam extrusion by using an underwater granulator. Foam density and morphological properties, such as cell size, cell size distribution, and cell density, were measured through different

This paper presents an enhanced gas chromatography–mass spectrometry method for the separation of cell gases in polyurethane foam. The novel method was then tested on several polyurethane foams produced at different mixing times, showing successful results. The measurement of gas content in polyurethane foams has been rarely considered in published literature. This parameter, indeed, plays a critical

Injection moulding is a well-established replication process for the cost-effective manufacture of polymer-based components. The process has different applications in fields such as medical, automotive and aerospace. To expand the use of polymers to meet growing consumer demands for increased functionality, advanced injection moulding processes have been developed that modifies the polymer to create

This work is aimed to study the application of a bio-based plasticizer, obtained by acetylation and epoxydation of cardanol, for the production of soft PVC foams. The use of epoxidized cardanol acetate allowed obtaining a more efficient foaming of soft PVC compared to phthalate plasticizer bis(2-ethylhexyl) phthalate (DEHP), mainly due to the lower viscosity attained in the decomposition range of azodicarbonamide

Polyurethane foams are widely used for insulation applications due to their high insulation properties as compared to conventional materials such as extruded polystyrene foam and mineral wool. In this study, soy-based polyurethane foams were prepared using five different surfactants while keeping other components such as soy-based polyol, diisocyanate, catalyst, and blowing agent (water) constant.

The open cell rigid polyurethane foam (ORPUF) was prepared by adding chemical cell openers including O-500 and AK-9903. The FTIR results of cell openers and open cell rate of ORPUFs showed that O-500 has more effective cell opening capacity. In the ORPUF foaming formulation using O-500 as cell opener, silane coupling agent (KH-550) modified kaolin (organo-kaolin) was introduced into ORPUF with different

The expanded polystyrene foam is widely used as a protective material in engineering applications where energy absorption is critical for the reduction of harmful dynamic loads. However, to design reliable protective components, it is necessary to predict its nonlinear stress response with a good approximation, which makes it possible to know from the engineering design analysis the amount of energy

Pure polyurethane foam and nanocomposite foam are used to absorb sound. In this study, hollow silica nanospheres and rigid silica nanoparticles were added to the polyurethane matrix and their sound absorption properties were investigated by impedance tube and compared with pure polyurethane foam. Reinforcement phase influences on the morphology of the matrix were studied by scanning electron microscopy

This work focuses on the development of foamed high temperature thermoplastic substrates for printed circuit boards. For this application it is necessary to achieve mean cell diameters smaller than 30 µm in order to be able to realize vias and high packaging densities (miniaturization). Different additives as nucleating agents, namely macro- and micro-crystalline talc, silica, calcium carbonate, and

Polyurethane foam is a kind of polymer composite material. The foaming turgidity and reaction temperature of polyurethane foam are closely related to its mechanical properties. According to our present knowledge, this study is the first time that fiber optic sensing technology has been applied to monitor the dynamics change in the foaming turgidity and reaction temperature of polyurethane foam during

Processing low density poly(urethane-isocyanurate) rigid foam boards still remains challenging, especially for high thickness panels. In particular, subsequent shrinkage of the foam panel during cooling and cross-linking of the matrix creates in-plane compressive stresses in the facing that can be relieved by buckling with a relatively uniform wavelength of a few millimeters. An extensive study in

The research proposed an aqueous emulsion foaming process to produce a viscoelastic epoxy foam having a density of 0.33–0.36 g/cm3 from the polyamide–epoxy adduct, which uses a reverse ratio of epoxy and polyamide hardener. The process is simple, economical and uses no surfactant, thanks to the emulsifying ability of polyamide hardener. Firstly, the mixture of excess polyamide, epoxy and sodium bicarbonate