Commodity plastics toughness

Plastic also refers to a material that has a physical characteristic such as plasticity and toughness. The general term commodity plastic, engineering plastic, advanced plastic, advanced reinforced plastic, or advanced plastic composite is used to indicate different performance materials. These terms and others will be reviewed latter in this chapter. Plastics are made into specialty products that have developed into major markets. An example is plastic foams that can provide flexibility to rigidity as well as other desired properties (heat and electrical insulation, toughness, filtration, etc.). 

PLLA has been widely used in biomedical applications. Further, it is believed to be an alternative to traditional commodity plastics for everyday applications since it is an environmental friendly polymer. However, its toughness and heat distortion temperature are not very satisfactory for these applications. 

Unplasticised PVC (UPVC) has a better resistance to sunlight and chemicals than other commodity plastics. The resistance can be improved by adding mineral fillers, while the toughness can be improved by adding a rubber phase. UPVC products are widely used on the exterior of houses (gutters, wall cladding, window frames) as well as waste-water systems. 

In spite of its inherent thermal instability (see Section 15.3.4), PVC possesses several attractive properties, such as economy of production and processing, and the ease of variation of its properties, with appropriate blending with other polymers or additives, from hard and tough materials to elastomeric ones. Currently, PVC ranks second only to polyolefins in terms of worldwide production among industrial polymers. This technical success is the result of considerable research in the field of degradation and stabilization of this polymer since its introduction as a commodity plastic in the middle of the 20th century. 

Polyolefins, one of the largest commodity polymeric plastics in the market place, have been widely studied over six decades covering synthesis, structural, physical, as well as mechanical properties point of views. However, the study on blends of polyolefins is rather scarce relative to their neat forms. One of the polyolefin blends that gained considerable attention is thermoplastic polyolefins (TPO) due to the enhanced impact strength and toughness of polyolefins. A typical example is a blend of polypropylene (PP) and ethylene-propylene mbber (EPR). EPR has been incorporated into PP through reaction in batch reactors or physical blending. The PP/EPR... 

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