PP : Polypropylene

Characteristics
Polypropylene is one of those rather versatile polymers out there. It serves double duty, both as a plastic and as a fiber. As a plastic it is used to make things like dishwasher-safe food containers. It can do this because it doesn't melt below 160 oC, or 320 oF. Polyethylene, a more common plastic, will anneal at around 100 oC, which means that polyethylene dishes will warp in the dishwasher.

Nylon

Characteristics
Nylon resin is a typical engineering plastic that features superior toughness, heat-resistance, and oil-resistance.

Applications
Used chiefly in automobile parts, connectors and other electronics components, and mechanical parts, Nylon also finds application in packaging and construction materials. More recently, Nylon has come to be used in more familiar applications such as office chairs and bicycle wheels.