Question

Which of the following items cannot be recycled?
A) plastic milk bottles
B) plastic food trays
C) cd/dvd cases
D) plastic cups

Answer 1

Instead of being discarded, plastic trash is collected and transformed into usable goods through a variety of procedures known as plastic recycling. Plastic recycling, when done correctly, may minimise landfill dependency, preserve resources, and protect the environment from plastic pollution and greenhouse gas emissions.

Complete answer:
Thermosets are a kind of polymer that cures to form well-defined, irreversible chemical networks that tend to grow in three-dimensional directions, causing crosslinking between its chemical components and giving the thermoset a strong and rigid structure that can withstand extreme temperatures.
After they have been cured, thermoset polymers or elastomers cannot be melted and reshaped. Except as filler material, this typically prohibits recycling for the same function. New advances involve thermoset epoxy resins that create crosslinked networks on controlled and confined heating, allowing for repeated reshaping, similar to silica glass, through reversible covalent bond exchange processes on warming above the glass transition temperature. Thermoset polyurethanes have also been found to exhibit transitory characteristics, allowing them to be reprocessed or recycled.
Plastic containers are generally dense and compact, allowing them to be mechanically separated into various types of plastics. Because plastic film and bags are difficult to sort mechanically, they are highly expensive to sort. Furthermore, recycling this type of plastic is a costly procedure.
Thermosetting polymers are used to make CVD/DVD cases, which cannot be recycled.

Note:
Thermosets can only be used as filler material and cannot be recycled for the same function. One of the most popular methods for getting rid of thermoset plastic is to recycle it. Due to its high temperature (up to $2000{}^\circ C$ ) and extended residence time, sheet moulding compound/fiber reinforced plastic (SMC/FRP) wastes are processed in cement facilities.