6 Physical Properties of Polymers that Require Rigorous Testing

Polymers are a large class of materials that have found its place in everyday products. Besides being used in various commercial applications, one can find polymer in everyday utility items ranging from plastic bottles, apparels, cars to what not. Even the tiniest objects like silicon rubber tips on mobile phone’s earbuds are made of polymer. Even in the human body, many proteins, Keratin and our DNA are made up of polymers.

The term polymer is coined from the Greek word meaning “many parts”. In simple terms, polymers are large molecules whose structure is made of a large number of smaller units bonded together. This chemical linkage gives it the of a series of building blocks.

Owing to their application in almost all domains of science, technology, and industrial purposes, one can find polymers all around them. Be it natural or synthetic polymer, both have found unmeasurable usage in human life. Used in all daily items like containers made of plastic, mirrors, jackets and shoes, footballs, valves, car parts and more, polymers are indispensable.

Holding such high commercial and utility, it is extremely crucial for a polymer sample to be tested in a polymer testing lab to test its suitability for a certain use. It is very important to check the physical and chemical properties of the polymer to be checked in a polymer testing lab to realize its full potential. These tests allow the manufacturers to understand the material better and assess their capabilities and limitations.

Below are the properties of polymers that are subjected to rigorous tests. 

• Hardness

Hardness is the measure of resistance to any deformation or damage in plastic and polymers. Polymers are tested for hardness as the test defines how easily scratch or dent during static loading can be made on the surface of a material. There are a variety of tests performed by polymer testing labs to check the hardness of polymer. The Vickers Hardness test, Brinell Hardness test, and Rockwell Hardness test are the most common tests which use a predetermined load to be placed on the sample after which the depth and indentation are determined.

• Shear

When it comes to polymer, properties like shear strain and modulus are notably important. This test involves placing a load on the sample using a mechanical apparatus to determine the weak spot where the material may generate a failure.

• Flexural

The polymer can be a flexible material which is why it is often the preferred one among rest. Polymer testing labs perform flexural tests to check the flexibility of the polymer sample. A three-point loading test is conducted to assess the flexural capabilities of a polymer. A bar of sample material is placed on two supports and the test load is kept midway between the sample. Another test conducted is the cantilever test to measure strength.

• Impact

Polymer testing labs perform a certain set of tests on polymers to check the durability of the product and indicate its service life. A particular impact test is chosen based on what condition the material may be exposed to in everyday use. Both drop weight testers and pendulum testers are used to check the impact on a polymer and ascertain its durability.

• Thermal

Other few tests performed by testing labs is to check the thermal properties of a material and find out its viability for an intended application. Through thermal testing, designers get an idea of the physical qualities, transitions, aging, the impact of additives and the effect of production conditions on the polymer sample in question.

There are four common ways of thermal testing through which chemical and physical transitions of sample material is assessed; Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Thermogravimetric Analysis (TGA) and Thermomechanical Analysis (TMA). While DMA tests are usually run for quality assessment like elastic modulus and mechanical damping, TMA is used to identify the material from its unique thermal fingerprint. TGA is applied to test for the amounts of plasticizers and filler materials.

• Adhesion

Most of the polymers have adhesive properties and this test is performed to check the degree of adhesion in a particular specimen. It is necessary to establish a failure point so as to assess the viability of the product. Measuring the bond strength, stringiness, tensile strength are some of the keys focuses in adhesion testing for polymers by polymer testing labs.

Conclusion 

Being the important materials in manufacturing processes as they are, polymers are used in varied processes. Proper testing based on their end use is hence critical to producing final products with utmost quality and strength to have a long life span. Modern Polymer testing labs use the latest technology in a controlled environment to expose the polymer samples to set conditions and their performance. Intelligence gained from years of experience aids in anticipating the right conditions to which a material may be exposed to in real life usage.