Formulation and Applications of Glycerol Polymers

Authors: Vaughn, Steven; Holser, Ronald

Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/2007
Publication Date: 10/10/2007
Citation: Vaughn, S.F., Holser, R.A. 2007. Formulation and applications of glycerol polymers [abstract]. Association for the Advancement of Industrial Crops. p. 11.

Interpretive Summary:

Technical Abstract: Increased production of biodiesel in the U.S. and Europe during the past several years has created an oversupply of glycerol, creating lower domestic profitability. In addition, increased petroleum prices have driven up the cost of synthetic polymers made from petrochemicals. Glycerol can be polymerized with phthalic acid to form polyesters which are commonly referred to as glyptal resins. Glycerol can also react with other di- or tricarboxylic acids such as azeleic acid or citric acid to form polymers with variable properties. The objective of this study was to examine the physical and chemical properties of polyesters formed by reacting di- and tri-carboxylic acids with glycerol, and examine the applications of these polymers. Glycerol was reacted at temperatures ranging from 75 to 290 deg C with the following organic acids: malonic (propanedioic); citric (2-hydroxy-1,2,3-propanetrioic); succinic (butanedioic); maleic (z-butenedioic); adipic (hexanedioic); phthalic (1,2-benzenedioic); suberic (octanedioic); azelaic (nonanedioic); and sebacic (decanedioic). Generally, temperatures below 100 deg C did not result in polymerization. Higher reaction temperatures generally created porous polymers, whereas lower (100-125 deg C) temperatures created dense polymers. Malonic acid tended to sublime at temperatures of 125 deg C or greater, and malonic, citric, succinic, and maleic acid-glycerol polymers decomposed when placed in water, while phthalic acid polymers tended to soften when placed in water. Adipic, suberic, azeleic, and sebacic acid-glycerol polymers were water-fast and flexible, although the longer-chain acids required extra reaction time. Adipic acid-glycerol polymers combined with a variety of organic compounds with differing chemical characteristics were cast in 20-cm-diameter pie pans to produce biopolymer mats. Preliminary data indicate that improved plant growth and pest protection can be achieved by the use of these mats around horticultural plants, such as tomatoes. The use of glycerol to produce glycerol-organic acid polymers for horticultural applications demonstrates an attractive novel use of this commodity.