CHEM 156 Study Guide - Final Guide: Ionic Liquid, Plastic Recycling, Carbene
Plastic pollution negatively affects wildlife and human environment
-
Effect of living organisms with plastic pollution: entanglement,
direct ingestion of plastic waste, exposure to chemicals within
plastics that cause interruptions in biological functions
-
Reducing plastic consumption and plastic recycling to attempt
plastic reduction
-
Polymer chemistry used widely to produce consumer products such
as synthetic polymers
-
Thermoplastic polyester
○
Excellent tensile and impact strength, chemical resistance,
clarity, processability, transparency
○
Relatively good thermal stability
○
Used in many products: textile fibers, food packaging materials,
soft-drink bottles
○
PET waste growing rapidly
○
Does not decompose naturally
○
PET (poly(ethylene terephthalate):
-
Used in clothing, carpeting, strapping, engineering resins
▪
Mechanical recycling: sorting, washing, and drying
postconsumer PET before melt processing to produce new
material (often lower quality and generally not suitable for
reuse in most beverage/ food packaging because of polymer
degradation during processing and high decontamination
requirements)
○
Depolymerization: cleavage of functional ester group by
reagents
▪
Chemical recycling: degradation (depolymerization) of polymer
back into monomers, then purified for subsequent
polymerization to yield high-quality plastic
○
Chemical recycling not economically viable relative to
mechanical recycling --> not wildly practiced
○
Starting monomers is low-cost
○
Recycling PET:
-
Depolymerization of PET using N-heterocyclic carbene from ionic
-
Recycling PET
Saturday, May 19, 2018
3:18 AM
Chem 156 Page 1
Document Summary
Plastic pollution negatively affects wildlife and human environment. Effect of living organisms with plastic pollution: entanglement, direct ingestion of plastic waste, exposure to chemicals within plastics that cause interruptions in biological functions. Reducing plastic consumption and plastic recycling to attempt plastic reduction. Polymer chemistry used widely to produce consumer products such as synthetic polymers. Excellent tensile and impact strength, chemical resistance, clarity, processability, transparency. Used in many products: textile fibers, food packaging materials, soft-drink bottles. Mechanical recycling: sorting, washing, and drying postconsumer pet before melt processing to produce new material (often lower quality and generally not suitable for reuse in most beverage/ food packaging because of polymer degradation during processing and high decontamination requirements) Chemical recycling: degradation (depolymerization) of polymer back into monomers, then purified for subsequent polymerization to yield high-quality plastic. Depolymerization: cleavage of functional ester group by reagents. Chemical recycling not economically viable relative to mechanical recycling --> not wildly practiced.
