Chapters authored
Study of the Technical Feasibility of the Use of Polypropylene Residue in Composites for Automotive Industry
Polypropylene (PP) is widely used in short-term use artifacts, rapidly discarded and should partially replace neat PP. In addition, it is one of the polymers most used in the automobile industry. This study shows the technical feasibility of partially substituting neat PP for a post-consumer counterpart (PPr), as well as adding ground glass (GP), used as filler in the polymer matrix. Mechanical and thermal properties of the recycled blends (PP/PPr) and composites (PP/PPr/GP) were evaluated. The results demonstrated that the blend with the highest PPr content obtained a statistically significant decline in elastic modulus, but adding 5 wt% of GP to this blend increased this property, achieving a similar value in relation to neat PP. The composite developed may be a promising tailor-made product with properties resembling those of the virgin plastic. Thus, the automotive industry seems to be a good option for the use of PPr and GP composites and blends, without increasing product requirements.
Part of the book: Plastics in the Environment
Processing and Properties of Plastic Lumber
Plastic residue can be processed into composites using wood flour, mineral fillers, plant or synthetic fibers to obtain plastic lumber, a substitute material for natural wood. The composition and processing conditions are largely responsible for the final characteristics of the plastic lumber. Factors such as density, particle size and moisture content in the material to be processed require extruders with specific technical characteristics, in order to reduce the residence time of the plastic inside the equipment, maintain a constant feed rate and ensure good degassing and homogenization of the components. The composites can be manufactured using single-screw, co- or counter-rotating conical or parallel twin-screw extruders. Plastic lumber exhibits different physical and mechanical properties from natural wood, including lower stiffness (elastic modulus) and superior weathering resistance.
Part of the book: Thermosoftening Plastics
End-of-Life Tire Destination from a Life Cycle Assessment Perspective
Tires are complex materials manufactured from vulcanized rubber and various other reinforcing materials. One billion end-of-life tires (ELTs) are discarded annually, drawing attention from society. Options for their disposal include reuse, retreading, regeneration, co-processing, pyrolysis, and recycling; however, the ideal alternative has yet to be established. Life cycle assessment (LCA) has been used to quantify their impact and support the decision-making process, in order to determine the most beneficial alternative from an environmental standpoint. Scientific studies on LCA have been carried out on different continents, mainly Europe, Asia, and America. The aim of this chapter was to review studies on the life cycle assessment of end-of-life tire disposal. The main treatment and final destination options were reviewed as well as the most important limitations and aspects of the technologies studied. The most common form of disposal is recycling, with mechanical recycling for use in synthetic grass exhibiting the best environmental performance according to scientific research. Energy recovery also shows good performance, largely due to the emissions prevented through energy conversion. Co-processed and retreaded tires are regularly used for comparison but typically display poor environmental performance in relation to the first two alternatives.
Part of the book: New Frontiers on Life Cycle Assessment