Novel Bioplastics and biocomposites from Vegetable Oils, (Thesis/Dissertation)

摘要

Polymeric materials have been prevalent in our everyday lives for quite a long time. Most of today's polymeric materials are derived from nonrenewable petroleum-based feedstocks. Instabilities in the regions where petroleum is drilled, along with an increased demand in petroleum, have driven the price of crude oil to record high prices. This, in effect, increases the price of petroleum-based polymeric materials, which has caused a heightened awareness of renewable alternatives for polymeric feedstocks. Cellulose, starch, proteins and natural oils have all been examined as possible polymeric feedstocks. Natural oils are commercially available on a large scale and are relatively cheap. It is projected that the U.S. alone will produce 21 billion pounds of soybean oil in the period 2008/2009. Natural oils also have the advantages of inherent biodegradability, low toxicity, high purity and ready availability. Most natural oils possess a triglyceride structure as shown in Figure 1. Most natural oils have a unique distribution of fatty acid side chains, along with varying degrees of unsaturation per triglyceride. Common fatty acid side chains in naturally occurring oils are palmitic acid (C16:0), a 16 carbon fatty acid with no unsaturation; stearic acid (C18:0), an 18 carbon fatty acid with no unsaturation; oleic acid (C18:1), an 18 carbon fatty acid with one double bond; linoleic acid (C18:2), an 18 carbon fatty acid with two double bonds; and linolenic acid (C18:3), an 18 carbon fatty acid with three double bonds. Of course, there are other fatty acids with varying degrees of unsaturation, but their abundance is usually minimal. All of the unsaturated fatty acids mentioned have naturally occurring cis double bonds, which is common for most unsaturated fatty acids. In addition, the afore mentioned fatty acids have the first double bond at the position of carbon 9 (C9), followed by carbon 12 (C12), if there are two degrees of unsaturation, then at carbon 15 (C15), if there are three degrees of unsaturation. In addition, the double bonds are not in conjugation.