Polymer Blend vs Composite
Many modern chemical industries apply green chemistry to safeguard the environment while producing various chemicals. Green chemistry strategies are mainly accomplished by reducing waste production, reducing raw material usage, reducing non-renewable energy source, reducing overall energy demand and reducing risks, hazards and costs. The usage of polymer blend and composite are two such strategies used in ‘green’ requirement of many industries. Polymer blends and composites are extremely useful due to the following reasons.
- They can be produced by low-cost raw materials without sacrificing their desired properties
- They can be used to prepare high-performance compounds
- Biodegradability and reusability of the end products
- Products can be developed using industrial waste products
- They can be used for broader applications.
The definitions of polymer blend and composites are quite contradictory although they are often used together. However, according to available literature, the key difference between polymer blend and composite is that the polymer blend is made up by mixing of two or more polymers to get a single phase, whereas composite is made up of combination of two or more elements resulting in a multiphase, multicomponent system, where each element reflects their distinct identities and properties. Further details on polymer blends and composites will be discussed in this article.
What is Polymer Blend?
A polymer blend is a combination of two or more polymers, which are physically mixed to obtain a single phase. That means, rather than obtaining the properties of each polymer separately, one set of properties is obtained by blending few polymers. Therefore, each polymer may not show its own desired property. Blends are usually obtained in a molten state or by dissolving in solvents. Polymer blends can be in various forms such as miscible one phase, miscible separated phase, alloys, compatible, incompatible, interpenetrating and semi-interpenetration polymer network. Polymer blends are mainly classified as compatible and incompatible polymer blends. Compatible polymer blends are miscible blends, where there are no separate phases, but a single phase. These type of blends provide superior mechanical properties. Incompatible polymer blends are the blends which form two well-defined separate phases after mixing. These types of blends generally have poor mechanical properties. However, incompatible blends are more common than compatible blends.
Polystyrene is a Homopolymer which is a miscible polymer blend
What is Polymer Composite?
Polymer composites are the compounds made up of two or more elements, which finally form a multiphase, multicomponent system. Each element has its own identity and maintains its physical and chemicals properties even after being integrated into a composite. In general, composite contains two components; polymer and non-polymer. The polymer component usually acts as the matrix while non-polymer component acts as the filler (ex: fiber, flake, metal, ceramic, etc.). However, in some cases, polymers are also used as fillers. Therefore, polymers can play the role as either the filler or the matrix in composites. Both synthetic and natural polymers can be used to make composites. Materials with superior properties for broader applications can be prepared by blending both natural and synthetic polymers. Even today many composites have been developed with the aid of natural polymers as they provide many advantages such as biodegradability, less toxicity, and availability. Wood and bones are two good examples of natural composites. Hemicellulose and lignin act as the polymer matrix in wood, while the cellulose fibers act as the filler. Fiberglass is an excellent example of a man-made composite.
Glass with a polymer
What is the difference between Polymer Blend and Composite?
Definition of Polymer Blend and Composite:
Polymer Blend: Polymer blend is a combination of two or more polymers, which are physically mixed to obtain a single phase.
Polymer Composite: Polymer composite is a compound made up of two or more elements resulting a multiphase, multicomponent system
Characteristics of Polymer Blend and Composite:
General Composition:
Polymer Blend: Polymer blends consist of two or more polymers
Polymer Composite: Polymer composites consist of polymer component and non-polymer component
Bonding Nature:
Polymer Blend: Polymer blends usually do not form strong chemical bonds between polymers.
Polymer Composite: Polymer composites have chemical and physical bonds between polymer and non-polymer.
References:
Kulshreshtha, A. K. (2002). Handbook of polymer blends and composites(Vol. 1). iSmithers Rapra Publishing.
Olatunji, O. (2016). Natural Polymers. Springer International Publishing: Imprint: Springer,.
Sperling, L. H. (2005). Introduction to physical polymer science. John Wiley & Sons.
Image Courtesy:
“Glass with a polymer” By Cjp24 – Own work (CC BY-SA 3.0) via Commons Wikimedia
“Expanded polystyrene foam dunnage” By User:Acdx – Own work, (CC-BY-SA 3.0) via Commons Wikimedia