Characteristics, Classification and Uses of Plastics

Plastics

Plastics refer to a wide range of organic, synthetic or semisynthetic materials made of long chains of polymers alongside some addictives.

Plastics show plasticity, which implies that they can be molded into a variety of solid shape and forms. A proper understanding of plastic is best shown through their characteristics (or properties) types, and uses.

Please read on cement here.

Characteristics of Plastics

• They are very light materials with great strength. This imply that they possess high strength regardless their light weight.

• They show plasticity. This means that they can be molded into various solid forms and complex, detailed shapes.

• They are good insulators. This imply that the do not conduct heat and electricity.

• They can melt or shrink easily at high temperatures. Please read on the concept of heat and temperature here.

• They are highly resistant to rusting or corrosion.

• They are often resistant to attacks from most acids, bases, oils, grease, water, atmospheric gases, and various common solvents.

• They are typically considered as non-biodegradable. This imply that they cannot be broken down by microorganisms; (that is, they do not undergo decomposition or decay).

• They come in a variety of colors. In fact, the color on a plastic may begin to change or fade when exposed to air and sunlight over a long period of time.

• They can pose significant pollution to the environment when burnt. Also, their non-biodegradability can also become a source of environmental pollution.

• Their surfaces can become easily scratched.

Please read on ceramics here.

Classification Of Plastics

Plastics are generally classified into two groups. These are thermosets and thermoplastics.

Thermosets

Thermosets are organic polymers that undergo an irreversible chemical curing process, creating a rigid, 3D network of cross-linked molecular chains. In simple terms, they are polymers that do not soften or change to liquid when heated. For this reason, thermosets cannot be remoulded. 

Examples of thermosets include polyester, amine, formaldehyde, epoxy resins, silicone, polyurethane, melamine, vulcanized rubber, polyester resin and bakelite. These are applied in the manufacture of shirt buttons, handles of cooking utensils and so on.

Please read on technology in basic science here.

Characteristics of Thermosets

Thermosets show the following characteristics:

• They retain their shape at high temperatures. Instead of melting, they will rather burn.

• They are structurally strong, rigid and durable than thermoplastics.

• They are generally much harder, but more brittle than thermoplastics.

• They are excellent for holding hazardous chemicals and chemical solvents like bases and acids. This is so because they offer structural rigidity, and high dimensional stability.

Please read on the properties and uses of nonmetals.

Uses of Thermosets

• They are good electrical and heat insulators. As a result, they can be used as heat-resistant handles in cooking utensils. They are also used for wire insulation due to their excellent electrical resistance. Please read on metals and their characteristics here.

• They are present in various kitchen products requiring heat, such as microwave ovens, toasters, alongside pressing iron handles.

• They can be used to manufacture durable items like boat hulls and bathtubs when reinforced with glass fibers.

• They are applied in the manufacture of toys and protective sports equipment.

• They can be used as laminate countertops since they are hard and durable.

• They are widely used as structural adhesives, binders, and for electronic encapsulation.

You can read on accident prevention techniques and safety rules in basic science here.

Thermoplastics

Thermoplastics are a category of plastics that soften and become pliable when heated, but will harden upon cooling. The melting and remolding of plastic as many times as possible is a physical change; and this makes them highly sustainable and versatile.

Examples of thermoplastics include Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC), Polypropylene (PP), Polystyrene (PS), High-Density Polyethylene (HDPE), Acrylic (PMMA), Nylon (Polyamide), Teflon (PTFE), Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC). They are used in the manufacture of  plastic buckets, plastic cups, jerry cans, etc.

Please read on the classification of matter in basic science here.

Characteristics of Thermoplastics

• They can be melted and molded numerous times, making them highly recyclable. Also, the thermoplastic Polypropylene (PP) can be used for manufacturing food containers.

• They have excellent strength-to-weight ratio. This implies that regardless their lightweight, they offer great structural strength, making them ideal in making products that carries heavy load.

• They are resistant to chemicals and corrosion, making them vital in harsh, outdoor and everyday use.

• They serve as excellent electrical insulators. For this reason, they are often used to coat electrical wiring and various electronic components.

• Thermoplastics like Polyethylene (PE) are used for the production of plastic bags while Acrylic is used as glass.

• They are used in the manufacture of pipes in plumbing work; for example, the thermoplastic Polyvinyl Chloride (PVC) can be used specifically for this purpose.

Please read on alloys in basic science here.

Uses of Thermoplastics

• They are very useful as packaging materials such as single-use and reusable water bottles (Polyethylene Terephthalate), grocery bags (Low-Density Polyethylene), and food storage containers (Polypropylene).

• Medically, Polycarbonate (PC) thermoplastic is used for manufacturing syringes, catheter tubing, and diagnostic equipment.

• Polyvinyl Chloride (PVC) is a thermoplastic often used in the construction of strong and firm piping used for plumbing systems, cladding and window frames.

• Acrylic (PMMA) thermoplastic is used in the manufacture of protective barriers, eyeglass lenses and face shields as a result of its optical clarity and weather resistance.

• Polycarbonate (PC) is used for manufacturing CDs, DVDs, bulletproof glass, parts of  television, and LCD screens.

• Polypropylene thermoplastic is applied in the manufacture of car bumpers, interior dashboard panels of cars, and car trim (often made from Polypropylene).

• Nylons can be used in the production of synthetic fabrics, toothbrush bristles and heavy-duty grocery bags.

Please read the next topic (rubber) here.

Please read basic science scheme of work for jss1 first term here.