Question

long answer questions no.5,7and8

Answer 1

5.....it is a type of thermoplastic. it is a poor conductor of heat and electricity so it is used for making electric switches to protect us from getting electric shocks. BAKELITE IS THERMO-PLASTIC ITS A VERY GOOD ELECTRICAL INSULATOR.

7.....Spandex is not comfortable because it does not absorb water.

8.....1: Polyethylene Terephthalate (PET)

One of the plastics you are most likely to come into physical contact with on a daily basis, depending on how it is made PET can be completely rigid or flexible, and because of its molecular construction it is impact, chemical and weather resistant and a terrific water and gas barrier.

Common uses of PET: Soft drink, water, cooking oil bottles, packaging trays, frozen ready-meal trays, First-aid blankets, polar fleece.

2: High Density Polyethylene (HDPE)

Incredibly strong considering its density, HDPE is a solid material that can tolerate high temperatures and strong chemicals. One of the reasons that HDPE is used so regularly is that it can be recycled in many different ways and therefore converted into many different things.

Common uses of HDPE: Cleaning solution and soap containers, Food and drink storage, shopping bags, freezer bags, pipes, insulation, bottle caps, vehicle fuel tanks, protective helmets, faux-wood planks, recycled wood-plastic composites.

3: Polyvinyl Chloride (PVC)

Cost effective to produce and highly resilient to chemical and biological damage, PVC is easy to work with and mould into shapes; making it an extremely practical material. In terms of properties, PVC is one of the most versatile. It can be used to create rigid, lightweight sheets, like Foamex, but it can also be used to make faux-leather materials like leatherette and pleather.

Common uses of PVC: Signage, furniture, clothing, medical containers, tubing, water and sewage pipes, flooring, cladding, vinyl records, cables, cleaning solution containers, water bottles.

4: Low Density Polyethylene (LDPE)

At general living temperatures LDPE is a highly non-reactive material, which explains why it has become one of the most common plastics in use at the moment. It can withstand temperatures approaching 100°C, and though it is not as strong as HDPE (its high density counterpart), it is certainly more resilient.

Common uses of LDPE: Trays, containers, work surfaces, machine parts, lids, '6-ring' drink holders, drink cartons, protective shells, computer hardware casings, playground fixtures (slides and the like), bin-bags, laundry bags.

5: Polypropylene (PP)

Strong and flexible, polypropylene is a very hard wearing plastic that, when melted, is one of the most effective materials for injection moulding. Having said that, it has quite a high tolerance to high temperatures, relative to other plastics, and is considered to be a food safe material.

Common uses of Polypropylene: Clothing, surgery tools and supplies, hobbyist model, bottle caps, food containers, straws, crisp bags, kettles, lunch boxes, packing tape.