CHEM 1100 Lecture Notes - Lecture 16: Low-Density Polyethylene, Polypropylene, Waste Hierarchy
Document Summary
Starting materials for plastics: petroleum, mostly for fuel, 3% go towards manufacturing plastics, non-renewable, other sources. Municipal waste i. 12% plastic, 31% paper (paper is made up of polymers) Paper is a large disposal problem: recycling. paper i. plastic: non-biodegradable, toxic emissions released, chemicals needed to recycle, most actually end up in landfills, heavier and 6x the space, fills landfills quickly (and slow to degrade, more expensive to produce, incineration. produces co2, h2o, and energy i. less volume in landfills ii. co2 contributes to greenhouse effect iii. burning pvc hcl gas acid rain phosgene, cocl2 (toxic gas) Low environmental damage, but must be monitored: biodegradation. natural polymers degraded this way i. enzymes can"t degrade synthetic plastics ii. solution: make plastics susceptible to enzyme digestion: landfill degradation. Recycling plastics: only 3. 5% plastics in us recycled, some heavily recycled, others almost never, polypropylene (pp) = 31. 8% recycling rate vs ldpe = . 4% recycling rate, plastics from renewable materials, consumer products made from polypeptide acid (dna)
