Polypropylene calcium carbonate reinforcement

Khimova, V. and Sain, M.M. (1995) Optimization of mechanical strength of reinforced composites. 1. Study on the effect of reactive bismaleimide on the mechanical performance of a calcium carbonate filled polypropylene. Angew. Makromol. Chem., 224, 9. 

A similar trend for a plateau limit in tensile behavior was also described by Jancar and Kucera (13) for calcium carbonate-reinforced composites of polypropylene using maleic anhydride to promote interfacial adhesion. Likewise, they observed convergence of interfacial shear strength value to that of the polypropylene yield strength. 

It is well accepted that the good properties of the isotactic polypropylene as an engineering polymer matrix in thermoplastic composite materials and engineering blends are seriously affected by the inability of this polymer to develop an adequate level of interfacial interaction with polar components such as mineral fillers (calcium carbonate) and reinforcements (talc, mica, wollastonite), synthetic reinforcements (glass fibers, carbon fibers, and nanotubes), or engineering polymers such as polyamide, aliphatic polyesters, and so on. 

Reinforcements are used to enhance the mechanical properties of a plastic or elastomer. Finely divided silica, carbon black, talc, mica, and calcium carbonate, as well as short fibers of a variety of materials, can be incorporated as particulate fillers. Incorporating large amounts of particulate filler during the making of plastics such as polypropylene and polyethylene can increase their stiffness. The effect is less dramatic when temperature is below the polymer s Tg. 

If higher stiffness is required, short glass reinforcement can be added. The use of a coupling agent can dramatically improve the properties of glass filled PP. Other fillers for polypropylene inclnde calcium carbonate and talc, which can also improve the stiffness of... 

Polypropylene that is reinforced with mineral fillers, such as talc, mica, and calcium carbonate, as well as with glass and carbon fibers. The maximum concentration is about 5 wt%, although concentrates with higher levels of filler or reinforcement are available. 

Polypropylene is a very versatile polymer. It has many properties that make it the polymer of choice for various applications (e.g., excellent chemical resistance, good mechanical properties and low cost). There are many ways in which the mechanical properties of polypropylene can be modified to suit a wide variety of end-use applications. Various fillers and reinforcements, such as glass fiber, mica, talc, and calcium carbonate, are typical ingredients that are added to polypropylene resin to attain cost-effective composite mechanical properties. Fibrous materials tend to increase both mechanical and thermal properties, such as tensile strength, flexural strength, flexural modulus, heat deflection temperature, creep resistance, and sometimes impact strength. Fillers, such as talc and calcium carbonate, are often used as extenders to produce a less-costly material. However, some improvement in stiffness and impact can be obtained with these materials. 

Calcium carbonate has also been used as a reinforcing agent for a range of polymers, including polyether ether ketone [174], acrylonitrile-butadiene-styrene terephthalate [175], polypropylene, and polydimethyl siloxane. 

General discussions of the effect of reinforcing agents on the thermal properties of polymers include glass fiber-reinforced polyethylene terephthalate [28], multiwalled carbon nanotube-reinforced liquid crystalline polymer [29], polysesquioxane [30, 31], polynrethane [31], epoxy resins [32], polyethylene [33], montmorillonite clay-reinforced polypropylene [34], polyethylene [35], polylactic acid [36, 37], calcium carbonate-filled low-density polyethylene [38], and barium sulfate-filled polyethylene [39]. 

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