Development Of Syntactic Foam Research Articles

SYNTACTIC FOAMS AS COMPOSITE MATERIALS FOR HIGH-TECH INDUSTRIES

The present review introduces the analysis and gathering modern ideas about the novel polymer composites, namely polymer syntactic foams, known as extremely widely used multifunctional materials with unique properties that meet the requirements of advanced high-tech industries. The main classifications, methods of synthesis and characteristization of various types of polymer foams were summarized. Special attention has been paid to structural features and properties of polymer syntactic foams. The main types of polymer matrices and fillers used for synthesis of thermosetting syntactic foams were characterized in details. The influence of initial composition and fabrication techniques applied on morphology, physical-chemical properties and application of composite materials comprising polymer syntactic foams in high-tech industries such as marine and underwater, aerospace, defense and transport has been also established. The review also highlights the analysis of world markets, trends and forecasting the further development of syntactic foams, especially high-performanced ones, disclosing their advantages and disadvantages. Presumable ways of modification of the existing types of polymer syntactic foams as well as perspectiveness of further progress in this research area to obtain the improved high-performance materials are also outlined.

Thermal stability and flammability characteristics of phenolic syntactic foam core sandwich composites

Polymeric foam core sandwich composites are the nascent materials used in marine and aerospace structural applications for its low-density characteristics. A special class of foam called syntactic foam is one of the promising core material having high specific properties. However, these polymeric foam core sandwich composite structures may encounter problems in correlation with temperature and fire. Damages that happen due to the variation in temperature and by the catch of fire are sometimes imperceptible which may lead to the deterioration of load carrying ability or catastrophic failure of these composite structures. Present investigation is focused on the possibilities of reducing the extent of damages due to variation in temperature and by the catch of fire by enhancing its thermal stability and flame resistance characteristics. This was achieved from the development of syntactic foam by embedding hollow micro-spherical particles in phenolic resin for fire containment or fire isolation. Result of the experimentation reveals that the phenolic syntactic foam core was thermally more stable than glass/epoxy face skins up to a temperature of 450°C. The minimum concentration of oxygen required for burning was found to be 30%, in which phenolic syntactic foam core helps in flame isolation, whereas E-glass/epoxy face skins contribute to flame spread in the event of burning of sandwich composites. Improved thermal stability and fire resistance characteristics of developed sandwich composites are attributed to the phenolic syntactic foam core and by its orientation.

Processing of cenosphere/HDPE syntactic foams using an industrial scale polymer injection molding machine

Rapid production of high quality components is the key to cost reduction in industrial applications. The present work is the first attempt of manufacturing syntactic foams, hollow particle filled lightweight composites, using an industrial scale injection molding machine. High density polyethylene (HDPE) is used as the matrix material and fly ash cenospheres are used as the filler. Development of syntactic foams with cenospheres serves dual purpose of beneficial utilization of industrial waste fly ash and reduction in the cost of the component. The pressure and temperature used in the injection molding process are optimized to minimize fracture of cenospheres and obtain complete mixing of cenospheres with HDPE. The optimized parameters are used for manufacturing syntactic foams with 20, 40 and 60wt.% cenospheres. With increasing cenosphere content, density and strength reduce and modulus increases. Surface modification of constituents results in rise in strength with increasing filler content. A theoretical model based on a differential scheme is used to estimate the properties of cenospheres by conducting parametric studies because of inherent difficulties in direct measurement of cenosphere properties. The potential for using the optimized injection molding process is demonstrated by casting several industrial components.