อิทธิพลของเส้นใยธรรมชาติและการเคลือบผิวโฟมแป้งด้วยไขขี้ผึ้งที่มีผลต่อสมบัติของโฟมแป้ง

Abstract

Starch is a natural polymer that can be used to make eco-friendly foam. However, neat starch foam has poor mechanical properties and is sensitive to moisture. In the first part of this study, properties of starch foam were proved using fibers from rubber seed shell (RSS) and water hyacinth (WH) and the improvements obtained were compared to improvements obtained with commercial cellulose (CL) fillers. RSS and WH fiber fillers improved the moisture sensitivity and mechanical and thermal properties of neat starch foam but, starch foam with 10%wt CL had the best mechanical properties and lowest moisture sensitivity. Also, RSS and WH fibers were modified by reducing the size of the fiber particles by planetary ball milling at 600 rpm for 40 min. The addition of modified RSS improved the properties of starch foam composites more than the addition of unmodified RSS. However, unmodified WH showed better results than modified WH. In the second part of the study, starch foam was coated with beeswax and the effects of the coating on the properties of the starch foam were investigated. The beeswax coating on the surface of starch foam composites reduced the water absorption of all the starch foams due to the presence of a hydrophobic phase. However, starch foam composites coated with beeswax showed poor mechanical properties because the difference of polarity between beeswax and starch foam composites impaired interfacial interaction. This behavior was confirmed by SEM microscopy.