Sometimes we wonder, why a product made from PVC is rock hard and why another tends to bend and have flexibility like Rubber…right?
Well, the answer to this is simple...PLASTICIZERS.
Plasticizers are Low in molecular weight and are added in synthetic polymers, commonly added to Plastics and Rubber, for multiple purposes, primary one of which is to increase the flexibility of material. Other such purpose includes, making the product softer, decreasing viscosity and to decrease the friction during manufacturing process. Broadly defined as Primary and Secondary Plasticizers for PVC industry, few of them are also used in Adhesives, Paint & Ink and Construction industry.
The Standard of Measuring Plasticizing Efficiency: Di 2-ethylhexyl Phthalate (DEHP), or widely known in the industry as Di Octyl Phthalate (DOP) is considered to be the Primary Plasticizer and it’s plasticizing efficiency, denoted as 1, is considered as base to measure the plasticizing efficiency of the entire range of Plasticizers.
In Industry, Plasticizers are classified based on their compatibility as Primary and Secondary Plasticizers.
Primary Plasticizers: Primary Plasticizers are highly compatible with polymers and can be used as a sole Plasticine. They enhances the flexibility and softness of polymer.
Secondary Plasticizers: Secondary plasticizers typically have limited compatibility and unlike the primary plasticizers, they cannot be used as sole plasticizers. While using secondary plasticizer can impart multiple benefits such as enhancing the solvency, lowering the friction, reducing viscosity etc., but the most important reason for using secondary plasticizers is Cost reduction.
Secondary plasticizers have a group of low cost oils known as Extenders. This includes mainly Chlorinated Paraffin - which is used in huge quantity as a secondary plasticizer for Cost Reduction purpose - Naphthenic hydrocarbons, Aliphatic hydrocarbos. Extenders also impart good fire resistance.
Similarly, we can understand Plasticizers based on the group of chemicals as, Phthalates, Adipates and Maleates
Phthalates: Phthalate group of Plasticizers are having wide compatibility and are used the most amongst all plasticizers. Di Octyl Phthalate (DOP), Di Isononyl Phthalate (DINP), Di Butyl Phthalate (DBP), Di Isobutyl Phthalate (DINP), Di Octyl Terpthalate (DOTP) are widely used phthalate plasticizers.
Adipates: As a replacement of Carcinogenic phthalates, Adipates have gained quite popularity in Plasticizers segment. They are well compatible in low temperature applications, apart from wide range of usage in different applications. Di Octyl Adipate (DOA), Di Isononyl Adipate (DINA) are widely used Adipate plasticizers.
Maleates: Maleate Plasticizers are highly suitable with Vinyl Acetate and PVC applications. They have high resistance to humidity and does not migrate. They are widely used in Paints and Adhesives. Di Octyl Maleate (DOM) and Di Butyl Maleate (DBM) are widely used Adipate plasticizers.
Others: There is a range of plasticizers, apart from the ones mentioned above, which has limited usage in the industry. These includes Tri Butyl Citrate (TBC), Try Octyl Citrate (TOC), and Benzoates etc. While, Chlorinated Paraffin and Epoxydised Soybean Oil (ESBO) are the two used in good amount in addition to the primary plasticizers.
We hope that now Plasticizers are simplified for you. In next part/blog we will see why different plasticizers are there in the market and what purpose it serves, all in a Simplified Way.