Application Note — Industrial & Environmental Applications — Notes

Polymer	Key Application	Why This Property Matters
HDPE	Milk containers, pipes, cutting boards	High strength, food-safe, rigid
LDPE	Shopping bags, cling film, squeeze bottles	Flexible, low cost, transparent
PVC	Water pipes, electrical cable insulation, flooring	Rigid (unplasticized) or flexible (plasticized), chemically resistant
Teflon/PTFE	Non-stick cookware, gaskets, medical catheters	Chemically inert, low friction, biocompatible
Polystyrene	Packaging (Styrofoam), disposable cups, CD cases	Lightweight, insulating, moldable
PAN (Orlon)	Sweaters, carpets, blankets	Soft, warm, durable wool substitute
Nylon-6,6	Parachutes, stockings, tire cords, toothbrush bristles	High tensile strength, abrasion-resistant
Dacron/PET	Clothing, soda bottles, audio/video tape	Strong, transparent, lightweight
Bakelite	Electrical switches, handles, billiard balls	Thermosetting, electrically insulating
PHBV	Biodegradable packaging, medical implants (sutures, screws)	Biodegrades in soil; processed like plastics

BOD in sewage treatment: Wastewater treatment plants reduce BOD from >100 ppm (raw sewage) to <5 ppm before discharge.
Montreal Protocol (1987): International phase-out of CFCs. Stratospheric O3 recovering; full recovery expected ~2050–2060.
Acid rain mitigation: Desulfurization of flue gases (removes SO2 before emission), catalytic converters reduce NOx from cars.
Heavy metal remediation: Phytoremediation (plants absorb heavy metals from soil); chelation therapy for heavy metal poisoning (EDTA for Pb).
Green chemistry in industry: H2O2 bleaching of paper (replaces Cl2), supercritical CO2 as solvent (replaces organic solvents).