Abstract
Due to global environmental problems and limited petroleum resources, we are interested in bio-based polymers made from renewable natural resources. Natural rubber (NR) is a bio-based natural polymer and it is soft and stretches well. The properties of NR can be tailored by adding fillers. Meanwhile, cellulose nano fiber (CNF) is a biomass material made by crushing wood into nano-order. Since CNF has several advantages of light weight, high strength, renewable and biodegradable, it is attracting attention as a filler to replace conventional natural rubber fillers, such as carbon black and silica. In recent years, several studies on CNF-added NR have been reported. However, most of these studies are related to the microstructure, and there have been no reports on the deformation behavior of the surfaces. The purpose of this study is to understand the reinforcing effect of CNF on the surface deformation of NR. In this paper, we considered the evaluation of mechanical properties (tensile strength, elongation, etc.) of CNF added-NR specimen, and observed the height distribution and microscopic height changes of the material surface by a confocal laser microscope. As a result, it showed different tensile behavior depending on the diameter of CNF. In the observation of height distribution, decreases of height distribution due to the pulling-out of the branching CNF during tensile deformation was observed.
