A feasibility study for the use of Thai silk as fiber reinforcement in polymer-based matrix | |
| Author | Nutchanin Tinnam |
| Call Number | AIT Thesis no.ST-03-13 |
| Subject(s) | Polymeric composites Fibrous composites Silk |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The most commonly used fibers other than asbestos are steel, glass, carbon and graphite, which contribute high strength and modulus for structural applications. However, these fiber have relatively high cost compared to natural fibers. This have resulted in a proliferation of exploratory studies on the use of natural fibers as reinforcement in fiberreinforced composites. Natural fibers appear to be the most promising material because they are inexpensive and are abundantly available in most of the developing countries. The purpose of this study is to conduct a feasibility study on the use of Thai silk as fiber reinforcement in polymer-based matrix. The main variables in this study are the fiber content and the matrix type. The fiber content is represented by the number of fabric layers and will be varied in three different fiber contents. Two types of matrices are investigated namely, epoxy resin and polyester resin. The composites being investigated were in the form of the thin rectangular plates. Unreinforced specimens are also tested for comparative purposes. Flexural tests under third-point loading are conducted, and mechanical properties relating to strength, stiffness and toughness are evaluated and discussed as indices of performance. The physical properties and tensile strength of Thai silk fibers are also determined. Test results showed for specimens using polyester as a matrix, addition of 4 layers of Thai silk (with a 0.887% volume of fraction) resulted in gain of 41 % in MOR, 65% in MOE and 14% in toughness compared to unreinforced specimen. Using 8 layers improved the gains in mechanical properties compared to unreinforced specimens to 97% in MOR, 105% in MOE and 238% in toughness. Extending the reinforcement to 12 layers resulted in increases of 134% in MOR, 98% in MOE and 613% in toughness of control. Using twelve layers of TSFRP (with a 2.660% volume fraction) showed comparable performance with using that 4 mesh layers of GFRP (with a 3.047% volume fraction). For specimens using epoxy as a matrix, addition of 4 layers of Thai silk (with a 0.887% volume of fraction) resulted in gain of 33% in MOR, 36% in MOE and 94% in toughness compared to unreinforced specimen. Using 8 layers improved the gains in mechanical properties compared to unreinforced specimens to 42% in MOR, 47% in MOE and 134% in toughness. Extending the reinforcement to 12 layers resulted in increases of 46% in MOR, 48% in MOE and 154% in toughness of control. Using twelve layers of TSFRE (with a 2.660% volume fraction) showed comparable performance with that using 4 mesh layers of GFRE (with a 3.047% volume fraction). The polyester specimens provided higher strength and higher stiffness, but lower toughness gains compared to epoxy specimens. In particular, polyester-based composite using 12 layers of Thai silk and 4 layers of glass fiber as provided substantial increases in strength, stiffness and ductility compared to Epoxy-based composite using 12 layers of Thai silk and 4 layers of glass fiber, respectively. The unreinforced specimens exhibited brittle modes of failure, while ductile modes of failure were found in Thai silk and glass fiberreinforced in polyester-based composite and very ductile modes of failure were evident in Thai silk and glass fiber-reinforced in epoxy-based composite. Using the same fiber volume fraction, Thai silk fiber-reinforced in polyester-based matrix cost 33% less than glass fiber-reinforced in polyester-based matrix, while Thai silk fiber-reinforced in epoxy-based matrix cost 12% less than glass fiber-reinforced in epoxy-based matrix. The cost of polyester is cheaper than the cost of epoxy by 86%. |
| Year | 2003 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pichai Nimityongskul; |
| Examination Committee(s) | Pennung Wamitchai;Barry, William J.; |
| Scholarship Donor(s) | Asian Institute of Technology (Partial Scholarship) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2003 |