Preparation and Characterization of a Biodegradable Mulch: Paper Coated with Polymerized Vegetable Oils

Kraft paper was coated with resins based on vegetable oils and then tested for mechanical properties, rate of biodegradation in soil, and ability to inhibit weed growth. Resins included oxidatively polymerized linseed oil (LO) and a polyester formed by the reaction of epoxidized soybean oil and citric acid (ESO–CA). Tensile strength of LO-coated paper (82 MPa) was slightly higher than uncoated paper (68 MPa), while the tensile strength of ESO–CA coated paper was somewhat lower (45 MPa). Elongations to break (3–8%) were similar for all samples. The rates of weight loss and tensile strength during soil burial decreased as follows: uncoated paper . LO coated paper . ESO–CA coated paper. The polymerized oils acted as barriers to penetration of microorganisms to the cellulosic fibers. Resin-coated papers inhibited weed growth for . 10 weeks, while uncoated paper was highly degraded and ineffective by 6–9 weeks. © 1999 John Wiley & Sons, Inc.* J Appl Polym Sci 73: 2159–2167, 1999