Difference Between ABS and PBT

The key difference between ABS and PBT is that ABS is comparatively a cheap polymer material but less durable, whereas PBT is comparatively an expensive and more durable polymer.

ABS and PBT are terms used to name two different polymer materials. ABS stands for acrylonitrile butadiene styrene polymer, while PBT stands for polybutylene terephthalate polymer.

CONTENTS

1. Overview and Key Difference
2. What is ABS 
3. What is PBT
4. Side by Side Comparison – ABS vs PBT in Tabular Form
5. Summary

What is ABS?

ABS is acrylonitrile butadiene styrene polymer material. It is a common thermoplastic material having its glass transition temperature at about 105 Celsius degree. This substance is amorphous and has no true melting point. Further, it is a terpolymer material that is made from the polymerization of styrene, acrylonitrile and polybutadiene. The proportions that we should take from each reactant can vary depending on the desired final product. E.g. the most common combination is 15-30% of acrylonitrile, 5-30% butadiene, and 40-60% styrene. This combination reaction forms a long chain of polybutadiene that is crisscrossed with shorter chains of poly9styrene-co-acrylonitrile).

The nitrile groups in this material can cause polarity of polymer chains, which can attract each other. This makes the substance stronger than pure polystyrene. In addition, the acrylonitrile groups can increase the chemical resistance, fatigue resistance, hardness, and rigidity of the material. The styrene groups in this material can cause the plastic to get a shiny appearance and can enhance hardness and rigidity, and make it easy to further process.

The most favourable properties of ABS include impact resistance, toughness, and rigidity. We can further amplify the impact resistance by increasing the proportions of polybutadiene compared to styrene. Moreover, ABS polymers are resistant to aqueous acids, alkalis, concentrated HCl and phosphoric acids. Alcohols, etc.

What is PBT?

PBT is polybutylene terephthalate. It is a thermoplastic engineering polymer. We can use this material as an insulator for electrical and electronic applications. We can classify this substance as a thermoplastic, crystalline polymer and as a type of polyester. This substance is resistant to solvents, and shrinking is negligible during forming. In addition, it is mechanically strong, heat-resistant up to about 150 Celsius degree temperature.

When considering the applications of PBT, it is useful for housings in electrical engineering. Also, it is important in automotive construction as plug connectors and in showerheads or irons. We can find this material processes into fibres of toothbrushes, false eyelashes, and also in the keycaps of some end computer keyboards.

What is the Difference Between ABS and PBT?

ABS and PBT are polymer materials having different chemical and physical properties. ABS is acrylonitrile butadiene styrene polymer material, while PBT is polybutylene terephthalate polymer material. The key difference between ABS and PBT is that ABS is comparatively cheap but less durable, whereas PBT is comparatively expensive and more durable. Further, ABS is made from the emulsion polymerization technique, while PBT is made from the polycondensation polymerization method. In addition, ABS is composed of acrylonitrile, butadiene, and styrene while PBT is composed of terephthalic acid or dimethyl terephthalate and 1,4-butanediol. Thus, this is another major difference between ABS and PBT.

Below is a summary of the difference between ABS and PBT in tabular form.

Summary – ABS vs PBT

ABS is the acrylonitrile butadiene styrene polymer material. PBT is the polybutylene terephthalate polymer material. The key difference between ABS and PBT is that comparatively, ABS is cheap but less durable, whereas PBT is expensive and more durable.

Reference:

1. “Acrylonitrile Butadiene Styrene (ABS) and Its Features.” Acrylonitrile Butadiene Styrene (ABS Plastic): Uses, Properties & Structure, Available here.

Image Courtesy:

1. “Citroën Méhari Nice IMG 1269” By Alexander Migl – Own work (CC BY-SA 4.0) via Commons Wikimedia

2. “PBT chemica struc” By Polimerek – Own work (Public Domain) via Commons Wikimedia