The key difference between polymer blends and alloys is that polymer blends are formed by a blend of at least two polymers, while alloys are formed by a blend of metals and nonmetals.
Polymer blends are analogous to metal alloys. Both these materials have at least two components combined with each other, forming a new material with enhanced properties.
CONTENTS
1. Overview and Key Difference
2. What are Polymer Blends
3. What are Alloys
4. Side by Side Comparison – Polymer Blends vs Alloys in Tabular Form
5. Summary
What are Polymer Blends?
Polymer blends are materials in which at least two polymers are combined together, creating a new material having different physical properties to that of initial components. We also call it a polymer mixture. This is a class of compounds that is analogous to metal alloys.
There are three broad categories of polymer blends as immiscible polymer blends, compatible polymer blends, and miscible polymer blends. Immiscible polymer blends are the most popular group of polymer blends containing materials with two polymers and two glass transition temperatures. Compatible polymer blends are a group of immiscible polymer blends that show macroscopically uniform physical properties. Miscible polymer blends are a group of polymers having a single-phase structure. We can observe a single glass transition temperature in this type of material.
Some examples of miscible polymer blends include PPO (polyphenylene oxide) – PS (polystyrene) polymer blend, PET (polyethylene terephthalate) – PBT (polybutylene terephthalate) polymer blend, etc.
What are Alloys?
An alloy is a metallic substance that contains at least one metal element along with other elements. These substances have enhanced properties when compared to properties of every single element they are made of. We can obtain the properties of alloys by mixing chemical elements in different percentages. Therefore, they give the desired properties by mixing different metals and elements in different amounts. Almost all alloys have a lustre due to the presence of the metal component. Alloys are also able to conduct electricity due to the presence of a metal component.
Figure 01: Brass is a type of Alloy
We can classify alloys in different ways. For example, they can be either homogenous or heterogeneous. Homogenous alloys have components distributed throughout the material uniformly. Heterogeneous alloys, on the other hand, have components distributed in an unorganized manner.
Furthermore, there are substitutional and interstitial alloys. Substitutional alloys are metal alloys formed from substituting one metal atom for another metal atom of similar size. Interstitial alloys are metal alloys formed by inserting smaller atoms into holes of the metal lattice.
What is the Difference Between Polymer Blends and Alloys?
Polymer blends are analogous to metal alloys. Polymer blends are materials in which at least two polymers are combined together, creating a new material having different physical properties to that of initial components. Alloys, on the other hand, are metallic substances that contain at least one metal element along with other elements. So, the key difference between polymer blends and alloys is that polymer blends are formed by the mixture of at least two polymers, while alloys are formed by the blend of metals and nonmetals.
The following infographic summarizes the differences between polymer blends and alloys in tabular form.
Summary – Polymer Blends vs Alloys
Both polymer blends and alloys have at least two components combined with each other to form a new material with enhanced properties. The key difference between polymer blends and alloys is that polymer blends are formed by a blend of at least two polymers, while alloys are formed by a blend of metals and nonmetals.
Reference:
1. “Alloy.” Science Clarified, Available here.
Image Courtesy:
1. “Brass 223 Win” By I, Arthurrh (CC BY-SA 3.0) via Commons Wikimedia