Question

What is the difference between HIPS and ABS in terms of chemical compositions? Explain the toughening mechanism associated with those two types of plastics.

Answer 1

High Impact Polystyrene Sheeting is a thermoplastic polymer which at room temperature is in a solid state, but if it is heated at high temperatures of over 100 °C it can then reach glass-liquid transition and becomes a viscous liquid which when cooled, turns rigid.

High Impact Polystyrene Sheeting (HIPS) is a synthetic polymer made using the monomer styrene which is a liquid petrochemical.

HIPS is also used as a lightweight plastic and because it’s inexpensive to produce this is often why it’s used to manufacture handling trays.

The High Impact Polystyrene Sheeting polymer is a long chain hydrocarbon containing alternating carbon centers which are attached to phenyl groups related to benzene. Containing the elements of carbon and hydrogen, the molecules are made of long hydrocarbon chains that contain thousands of atoms. When polystyrene is heated, this means the chains slide past one another and this intermolecular weakness means that it’s flexible and elastic, so it can be molded at high temperatures.

Polystyrene occurs when styrene monomers interconnect. During this process which is known as polymerization, the carbon-carbon pi bond breaks and a new single carbon-carbon bond forms and attaches itself to another styrene monomer in the chain. This sigma bond becomes much stronger than the pi bond which was broken and therefore becomes much more difficult to depolymerize.

ABS stands for Acrylonitrile butadiene styrene. ABS is a thermoplastic and is extremely tough, it is also surprisingly light, which means it is easily transportable. ABS plastic sheets are both chemical and weather resistant making the thermoplastic an ideal material to use for outdoor applications.

It has high impact resistance properties which do not decrease under lower temperatures. This makes it a very impressive thermoplastic that stands out amongst other materials.

The highly durable ABS lends itself to many different uses, both commercial and industrial. Its high impact resistance makes it a popular material to use for car bumpers. This quality combined with its weather and chemical resistance, also means it is perfect to use for manufacturing sports equipment such as canoes, and lacrosse sticks. Children’s toys and musical instruments are also often made out of ABS such as clarinets, and Lego bricks depending upon the plastic’s durability.

It is lightweight in comparison to its strength and durability also making it great for protective headgear for use on construction sites and extreme sports.