Polymer foams, reinforcements

Polymer International 51,No.7, July 2002, p.601-6 PHYSICAL STUDIES OF FOAMED REINFORCED RUBBER COMPOSITES. PART I. MECHANICAL PROPERTIES OF FOAMED ETHYLENE-PROPYLENE-DIENE TERPOLYMER AND NITRILE-BUTADIENE RUBBER COMPOSITES... 

In the last decade several novel types of gas-filled polymers appeared which belong to the second generation integral (structural) plastic foams syntactic foams reinforced polymer foams multilayer foams (foamed laminates), metallized plastic foams mineral and metallic foamed materials obtained on the basis of foamed polymers laminated constructions on the basis of foamed polymers and monolithic (unfoamed) plastics, metals, paper, leather, etc. 

Polyimide characterised by thermal and thermal-oxidative stability at elevated temperatures, chemical resistance and good mechanical properties is relatively new in the family of polymer foams [3]. In some cases, depending on the nses, additional reinforcement can be inclnded. Examples are fibre reinforced foams and syntactic foams which are composites containing hollow glass, ceramic or plastic micro-spheres dispersed throughout the polymer matrix. 

Guzman M E, Rodriguez A J, Minaie B and Violette M (2012), Processing and properties of syntactic foams reinforced with carbon nanotubes , J Appl Polym Sci, 124, 2383-2394. 

Elastomers are flexible. Plastics can provide flexible to rigid foams. Reinforced plastics or composites are plastics (polymers or resins) with reinforcing additives, such as fibers and whiskers, added, basically, to increase the product s mechanical properties. Throughout this book these terms are used precisely according to their respective areas of interest. 

Despite being proven to be an effective reinforcement for polymers, nanoclay-reinforced syntactic foam (NCRSF) has only been explored in recent years (John, Nair, and Ninan, 2010 Maharsia, Gupta, and Jerro, 2006 Peter and Woldesenbet, 2008). It would be interesting to evaluate a possible synergistic behavior in hybrid syntactic foams comprised of a matrix, hollow microspheres, and nanoclay particles. 

Fan, H., A. Tekeei, G. J. Suppes, and F. H. Hsieh. 2012. Properties of biobased rigid polyurethane foams reinforced with fillers Microspheres and nanoclay. Inter J. Polym. Sci. Vol. 2012 Article ID 474803. 

Dyson, R. W. (ed.), Engineering Polymers , Chapman and Hall, New York, 1990. The book discusses polymeric materials currently in use as engineering materials. They include thermoplastics, elastomers, polymer foams, fiber-reinforced composites, films, and polymers in telecommunications and power transmission. 

Use of polymer alloys and blends as matrices for composites, reinforcements, and foams. 

Based on this analysis it is evident that materials which are biaxially oriented will have good puncture resistance. Highly polar polymers would be resistant to puncture failure because of their tendency to increase in strength when stretched. The addition of randomly dispersed fibrous filler will also add resistance to puncture loads. From some examples such as oriented polyethylene glycol terephthalate (Mylar), vulcanized fiber, and oriented nylon, it is evident that these materials meet one or more of the conditions reviewed. Products and plastics that meet with puncture loading conditions in applications can be reinforced against this type of stress by use of a surface layer of plastic with good puncture resistance. Resistance of the surface layer to puncture will protect the product from puncture loads. An example of this type of application is the addition of an oriented PS layer to foam cups to improve their performance. 

We use variants of profile extrusion to produce tubing -with diameters of less then 1 mm and pipes with diameters exceeding 1 m, Wall thicknesses can vary from a few tens of micrometers up to several centimeters. Extruded window and door frames are more complex than pipes. Such profiles are largely hollow with internal ribs and fins that reinforce and divide the interior into two or more channels. We use solid rubber profiles in applications such as door seals and windshield wipers. We can produce foamed extrudates by incorporating a blowing agent, such as butane or carbon dioxide, into the polymer in the molten state. As the polymer exits the die, its internal pressure drops and the dissolved gas expands to form bubbles within the product. Examples of foamed extrudates include pipe insulation and automobile door gaskets. 

Epoxy resins find a large number of uses because of their remarkable chemical resistance and good adhesion. Epoxy resins are excellent structural adhesives. When properly cured, epoxy resins can yield very tough materials. They are used in industrial floorings, foams, potting materials for electrical insulations, etc. One of the principal constituents in many of the Fibre-reinforced plastics (FRP) is an epoxy polymer. 

The heat distortion temperature of styrene polymers is insufficient for some applications, but can be improved by copolymerization with monomers such as -methylstyrene or maleic anhydride. Maleic anhydride copolymers are excellently suited to the manufacture of foamed articles. The advantages of glass-fiber reinforcement are greater in such copolymers than in polystyrene itself. 

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