Location: Plant Polymer ResearchTitle: Mechanical, thermal, and moisture properties of plastics with bean as filler) Author
Submitted to: Journal of Biobased Materials and Bioenergy
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/11/2012
Publication Date: 3/1/2012
Citation: Sutivisedsak, N., Cheng, H.N., Liu, S.X., Lesch, W.C., Tungsrud, R.R., Finkenstadt, V.L., Biswas, A. 2012. Mechanical, thermal, and moisture properties of plastics with bean as filler. Journal of Biobased Materials and Bioenergy. 6(1):59-68. Interpretive Summary: The use of fillers in polymers has been around for a long time. In addition to lowering the cost, the filler sometimes improves the end-use properties of the polymers. In the present study, we looked at edible beans as possible polymer fillers. Two polymers of interest are poly(lactic acid) (PLA) and low density polyethylene (LDPE). PLA is a biodegradable polymer that has found application as sutures, stents, dialysis media, and drug delivery devices. LDPE is a high-volume industrial polymer that has numerous uses, such as packaging, tubing, plastic wraps, and various molded equipment and parts. The experimental set-up was designed such that the processing conditions including temperature profile, type of extrusion screw, and screw speed were controlled. Under the experimental conditions studied, both materials readily formed composites with bean filler. The composites exhibit different physical properties and may potentially be used for selected applications. In this study, we studied the use of edible beans as possible fillers with polymers poly(lactic acid) (PLA) and low density polyethylene (LDPE). The resultant blends exhibit novel physical properties, such as moisture retention, stiffness, biodegradability. These blends may potentially be used for drug delivery devices, packaging, tubing, plastic wraps, and various molded equipment and parts. This discovery will benefit bean growers from North Dakota and Minnesota who funded this research.
Technical Abstract: Experiments on polymers using beans as fillers are reported herein. We are looking for desirable mechanical, thermal and moisture properties at economical costs. Poly(lactic acid) (PLA) is studied as the polymeric matrix because it is available and biodegradable. Although the physical properties are reduced with filler loading, the polymer-filler composite has good water and moisture uptake characteristics and can perhaps be used as polymeric moisturizing or water retention agent. Low density polyethylene (LDPE) is next studied for its low cost and its versatility. Tensile strength and elongation decrease with increasing filler content, but Young’s modulus increases. The bean filler may be useful for LDPE if a stiffer or cheaper polymer is needed. There are also some changes in thermal properties in the presence of the filler. The effects of plasticizers such as glycerol and crosslinkers such as maleic anhydride are also studied in several cases.