Comparison of mechanical properties of polypropylene / starch reinforced with nano and micro- cellulosic fibers

Document Type : Research Paper

Authors

1 Ph.D. Student, Wood and Paper Science and Technology, Faculty of Natural Resource, University of Gorgan, Gorgan, I.R. Iran

2 Prof., Wood and Paper Science and Technology, Faculty of Natural Resource, University of Gorgan, Gorgan, I.R. Iran

3 Asssoc. Prof. of Polymer Chemistry, Chemistry Department, University of Tehran, Tehran, I.R. Iran

Abstract

Regarding the development and application of biocompatible composites in various sectors, including packaging industry and disposable containers, consideration of the methods for improving mechanical properties is essential. The purpose of this study was to produce bio-composites with a mixture of polypropylene as a matrix, starch as a filler, and nano/micro cellulose fibers as reinforcing agent. For this study, polypropylene was used as a matrix, starch as filler in two levels (30 and 40 wt%) and cellulose nanofibers at three levels (0, 1 and 2 wt%) and cellulose micro-fibers in three levels (0, 5, and 10 wt%) was used as a reinforcing agent. MAPP was used as a coupling agent and glycerol as a plasticizer. Raw materials were mixed in a co-rotating twin-screw extruder. In this stage, TPS produced and nano and micro-fibers of cellulose dispersed in polymeric matrix. Then the granules obtained from the extruder were transferred to the injection device to obtain test specimens. The morphology of the samples was studied by FE-SEM. The results obtained from the experiments were analyzed by using a factorial design in a completely randomized block design with SPSS software; also, Duncan test was used to compare group mean. The results showed that the addition of nano and micro-fibers of cellulose increased the flexural and tensile strength of the specimens. Samples made with 30 wt% starch and 2 wt% cellulose nano-fibers had the most flexural and tensile strength.

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