| Popis: |
Publisher Summary This chapter discusses the influence of degraded, recycled PP on incompatible blends. The recycling of post-consumer polyolefins has attracted much interest because these resins—low density polyethylene (LDPE), high density polyethylene (HDPE) and polypropylene (PP)—are some of the most common polymers in the domestic plastic waste stream. Recycled plastic can be obtained by two different approaches: a two-step process, involving plastics fractionation and processing of the separated plastics fractions; and a single-step process, using directly the mixture of plastic residues. Reprocessing mixed polyolefin waste can lead to products with lowered mechanical properties, because these polymer mixtures are usually incompatible. This chapter investigates the compatibilizing action of molecularly modified, recycled PP on the mechanical properties of 50/50 PP/HDPE blend, as suggested by preliminary experiments carried out in the laboratory. Moreover the experimental results suggest that the degradation that occurred in PP molded, post-consumer artifacts after exposition to natural, uncontrolled outdoor conditions provided spontaneous, non-oxidative chemical modifications on PP molecules that brought a certain degree of compatibilization action toward polyolefin residues. |
