Thermoplastic And Thermosetting Plastic are two different types of plastics which differ fundamentally in their molecular structure, behaviour under heat, and ability to undergo chemical changes.
While both plastics offer distinct advantages and applications, their unique properties cater to different needs across industries. In this article, we will discuss Thermoplastic and Thermosetting Plastic including the key differences between them as well.
Table of Content
What is Thermoplastic?
Thermoplastic is a type of polymer that becomes soft and pliable when heated and solidifies upon cooling. This property allows thermoplastics to be molded and reshaped multiple times without undergoing significant chemical changes.
Molecular structure of thermoplastics typically consists of long, linear or branched polymer chains held together by weak intermolecular forces. When heated, these intermolecular forces weaken, allowing the polymer chains to slide past each other and enabling the material to become flexible and moldable. Upon cooling, the intermolecular forces reassert themselves, causing the material to solidify and retain its new shape.
Examples of Thermoplastic
Common examples of thermoplastics include:
- Polyethylene (PE): Polyethylene is one of the most widely produced thermoplastics, known for its flexibility, toughness, and chemical resistance.
- Polypropylene (PP): Polypropylene is a versatile thermoplastic with excellent chemical resistance, stiffness, and high melting point.
- Polyvinyl Chloride (PVC): PVC is a widely used thermoplastic known for its durability, weather resistance, and flame-retardant properties.
- Acrylonitrile Butadiene Styrene (ABS): ABS is a tough and impact-resistant thermoplastic commonly used in automotive parts, consumer electronics (such as computer keyboards and housings), and toys.
Other than these some other common examples are Polystyrene (PS), Polyethylene Terephthalate (PET), Polycarbonate (PC), Polyamide (Nylon), Teflon, etc.
Physical and Chemical Properties of Thermoplastic
- Thermoplastics have low melting points
- Thermoplastics are generally lightweight and flexible
- Thermoplastics are resistant to chemicals, impact, and moisture
What is Thermosetting Plastic?
Thermosetting Plastic, also known as thermoset, is a type of polymer that undergoes irreversible chemical changes when heated. This property of thermosetting plastic leads to the formation of a three-dimensional network structure.
Unlike thermoplastics, which soften when heated and can be reshaped, thermosetting plastics undergo a process called curing, during which polymer chains cross-link to form a rigid and durable material.
Examples of Thermosetting Plastic
Common examples of thermosetting plastics include:
- Epoxy Resin: Epoxy resins are versatile thermosetting polymers known for their exceptional adhesive properties, high chemical resistance, and mechanical strength.
- Phenolic Resin: Phenolic resins, derived from phenol and formaldehyde, are renowned for their excellent heat resistance, electrical insulation, and flame-retardant properties.
- Polyester Resin: Polyester resins, produced by the reaction between unsaturated dibasic acids and diols, exhibit high strength, corrosion resistance, and dimensional stability.
Other than these there are some more examples of thermosetting plastic such as Polyurethane Resin, Silicone Resin, Melamine Resin, Vulcanized Rubber, Bakelite, etc.
Physical and Chemical Properties of Thermoplastic
- Thermosetting plastics have high melting points
- Thermosetting plastics are generally rigid and strong
- Thermosetting plastics are also highly resistant to heat, chemicals
Difference Between Thermoplastic And Thermosetting Plastic
Thermoplastic and thermosetting plastic are two types of plastic distinguished by their thermal behavior. Some common differences between them include:
|
Property |
Thermoplastic |
Thermosetting Plastic |
|---|---|---|
|
Softening Behavior |
Softens when heated, solidifies upon cooling, reversible process |
Undergoes irreversible chemical change upon heating, does not soften upon reheating |
|
Melting Point |
Thermoplastics have low melting temperatures | Thermosetting plastics have high melting temperatures |
| Molecular Structure | Linear or branched polymer chains, weak intermolecular forces | Three-dimensional network structure, covalent cross-links between polymer chains |
|
Molecular Weight |
Thermoplastic is lower in molecular weight | Thermosetting Plastic is high in molecular weight. |
| Recyclability | Recyclable, can be melted and reshaped multiple times | Generally not recyclable due to irreversible curing process |
| Examples | Polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) | Epoxy resins, phenolic resins, polyester resins |
Similarities Between Thermoplastic and Thermosetting Plastic
Thermoplastic and thermosetting plastic share similarities as polymeric materials derived from polymerization processes. Both are versatile and used across industries. They have environmental impacts and are composed of long-chain molecules, but differ in their response to heat and reshaping capabilities.
Uses of Thermoplastic and Thermosetting Plastic
Uses of Thermoplastic
Some common uses of thermoplastics include:
- Packaging: Thermoplastics such as polyethylene (PE), polypropylene (PP), and polystyrene (PS) are widely used for packaging materials due to their lightweight nature, durability, and ability to be molded into different shapes.
- Construction: Materials like polyvinyl chloride (PVC) and acrylonitrile butadiene styrene (ABS) are commonly used in construction sector to make pipes and fittings, insulation materials, window profiles, etc.
- Electronics: Many electronic devices contain thermoplastic components due to their electrical insulation properties and ability to be molded into intricate shapes.
- Textiles: Thermoplastic fibers such as polyester and nylon are widely used in textile manufacturing for clothing, carpets, upholstery, and industrial fabrics.
Aerospace, Sports, Medical, 3D printing, Automotive, etc are some more other industries where thermoplastics are used.
Uses of Thermosetting Plastic
Thermosetting plastics are widely employed in sectors such as aerospace, automotive, construction, and electrical. Epoxy resins, for example, are used in adhesives, varnishes, and composite materials, whereas phenolic resins are found in computer chips and electrical insulation.
Conclusion
In conclusion, plastic is a versatile, long-lasting, and low-cost material that is widely employed in a variety of sectors. Plastic is classified into two types: thermoplastic and thermosetting plastic. Thermoplastics melt when heated and can be reshaped. They’re like playdough that can be reused. Thermosetting plastics harden permanently when heated, like baking a cake—it can’t go back to being dough. Knowing the difference helps pick the right material.
FAQs on Thermoplastic and Thermosetting Plastic
What is an Example of a Thermosetting Plastic?
An example of a thermosetting plastic is Polybenzimidazole (PBI), which is known for its outstanding thermal stability and high performance in engineering applications.
Define thermoplastic.
Thermoplastic, also known as thermo-softening plastic, is a type of plastic polymer that is malleable or moldable at high temperatures but hardens when cooled.
What are Examples of Thermoplastic?
Polyethylene, polypropylene, polyvinyl chloride, polystyrene, polybenzimidazole, acrylic, nylon, and Teflon are examples of thermoplastics.
Which is the first thermosetting plastic?
Leo Hendrik Baekeland created the first thermosetting plastic under the name “Bakelite” in 1909.