Surface energy is the important property of solids. It is molecular forces on the surface a material. To put it bluntly, it is an attraction or a repulsion force that is exerted by one materials surface onto another surface or a another material.
Surface energy of polymers explained
If plastic surface has high surface energy the liquid will spread. On the other hand, if you have a different situation, with low surface energy on a plastic surface – then the liquid tend to bead up and will not spread out. This will result in gaps, air bubbles, contamination or pinholes. If the surface energy of plastic surface is too high it will be difficult to control the flow of the paint you wish to paint upon the polymer.
Polymer – the same as plastic?
Is simply another name for plastics which is made of many repeating units. It is made of many molecules which bind together to form a long coherent chain.
Based on the molecules they are made of, and how they are put together and constructed – is what makes polymers so interesting.
The polymers looks, acts and feel different, all depending on how the molecules are connected together. Some are very hard, some are rubbery and some very soft. For example, many synthetic organic materials are used as plastics and in that way have a very soft surface.
The structure is composed of hydrocarbon compounds of hydrogen and carbon examples are for example: polystyrene, Polyethylene, polypropylene, polybutylene and something called polymethylpentene.
Polyvinylchloride (PVC) has chlorine attached to the carbon backbone while in Teflon, fluorine is attached to carbon backbone. Most of them are thermoplastic – which implies that once they are formed they can be reheated and reformed over and again many, many times.
The characteristics of Polymers
Resistance to chemicals. Like most cleaning liquids packaged in plastic containers emphasizes the need for chemical resistance. Most plastics provide:
- a safe
- non-breakable packaging
- for chemical solvents.
It can be both a thermal and electrical insulator as you can see around the house. Here you have all cords, appliances, electrical outlets and wiring. All plastics are extremely lightweight – but have a lot of strength. They can be processed in various ways. For example, plastics can be mixed with solvents to form into something as useful as paints or adhesives.
Polymers are made of petroleum but not always. Sometimes they are made from renewable materials as well.
Surface tension (Read more on the topic here)
It is a property of liquids which has a molecular interaction because of the forces between the molecules in the liquid provided. The molecules on the surface of the liquid does not act like molecules all around the surface. And how do you do this: test inks are an excellent tool for surface determination, quality assurance. They can be used during ongoing production, and determination of accurate parameters.
Surface tension is the key to the bonding of synthetic plastic boxes and tubes.
With a low surface tension, the resultant bond is very poor because adhesion occurs only at the points where glue droplets form – se more on this below. As a result of this process, they cohere strongly to those associated with them on the surface through a surface film which creates a tension. This on the other hand, makes it hard to move an object through the surface.
Surface tension is the elasticity of the fluid surface which makes it get less surface possible. The surface tension of the material is equal to the value of the test ink last used that did show good wetting for at least 2 seconds. It’s dimension is force per unit length or energy per unit area – it is how measurement is done. Energy per unit area also called “energy on the surface” applied to solids.
It is also the result of cohesive forces between the molecules of the liquid. We can see effects of tension with water surfaces. Rain water on the waxy surface of the leaf adheres less to the leaf and more to itself. That makes the water cluster into drops on the surface. Because of the surface tension the water drops attain the shape of a sphere which has small surface compared to the volume ratio. When the objects are denser than water – they tend to float if the object is nonwettable.
Waterstrides also use this tension on the surface to be able to walk on the pond surface.
Tension on the surface between two dissimilar liquids of oil and water for that sake, which is the reason for separation of water and oil, which is also called “interface tension” between liquids. Tears of wine on the sides of the glass of an alcoholic drink are also caused by the tension between different surfaces like water and the ethanol present in the alcoholic beverage.