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Fall 1997 - Article 1

From The Lab
Polymer Properties

How many times have you heard the words "hard" or "soft" or "thermoplastic" used to describe a floor finish? These are terms we often don't completely understand. To make things even more difficult, many of these terms are misused or misapplied within our industry. Essential Industries would like to set the record straight by exploring some of the common properties of floor finishes.

All polymers fall into one of two broad classes: Thermoplastic and thermoset. Linear polymers such as polyethylene, polyester and nylon are usually thermoplastic. They soften or melt when heated and will dissolve in suitable solvents.

Thermoset polymers have elaborately cross-linked structures, decompose when heated and are insoluble. Examples would be two-part epoxy resins, polyurethanes such as our oil-modified OMU Wood Seal (#230) and alkyd resins. All floor finishes are thermoplastics -- not just high speed finishes as is commonly thought.

Thermoset and thermoplastic polymers can be further classified as follows:

1. hard and tough
2. hard and strong
3. hard and brittle
4. soft and weak
5. soft and tough.

A hard polymer is one which has a high tensile strength (break point); a soft polymer has a relatively low tensile strength. A tough polymer has high elongation (ability to greatly stretch); brittle refers to little or no elongation. The chart below shows common polymers and the relationship of strength versus elongation.

Floor finishes often incorporate multiple classifications since many finishes use polyethylene wax, urethanes, acrylics and resins -- all of which can vary on the hardness and toughness scale. The research and formulating chemists create a product that meets a specific market need by varying the amount and types of the above polymers.

Essential's first generation high speed finish (Spectacular) was soft and tough. This allowed for excellent reparability, durability and buffability. Later generation high speed products, (Eccothane™ #274 and Silhouette® #281), are still classified as soft and tough but they also incorporate more hardness through unique polymers. This gives the finishes more black mark and scuff resistance. Essential's dri-brite finishes (Durabrite® #253 and Pro-Brite™ #290) are much harder since they are designed to resist almost all marking. Conversely, they do not buff and repair as well as the softer products.