The Fundamentals of Plasticizer Selection

摘要

ASTM D-883-98 defines a plasticizers as "a substance incorporated in a material to increase its workability, flexibility or distensibility". This is a definition that incorporates the two technical industrial drivers of the early 20th century. We needed and still need the ability to process high molecular weight polymers, and our goal is to develop polymer compounds that have a flexibility necessary to be useful in product design. The history of plasticizers is long and colorful. The start of commercialization of technology in PVC is much shorter, starting around 1935. In a period of less than 75 years the industry went from a handful of plasticizing compounds to a few hundred in 30 years and back to a handful of commercially significant materials today. During this time period PVC compounding progressed from an art to a science. Chemistry, engineering and raw materials supply have evolved into the commercial landscape we see today. If one looks at the worldwide usage of plasticizers it is easy to conclude that esters are the most effective plasticizers, and by some definitions, are perhaps the only plasticizers for PVC. This paper will not address the definition of plasticizers in the broadest sense introduced in the first paragraph. The portion of the definition related to workability for PVC is now studied within the disciplines and concepts of the materials more often called lubricants, process aids and modifiers. Most of these materials meet the early definition and do plasticize polymers. Many of these products are esters.