1. ICCS18 18th International Conference on Composite Structures 15 to 18 June 2015 Lisbon The Importance of Sample Preparation of Wood Polymer Composites for FTIR Spectroscopy and Thermal Analysis
This result strengthens the possibility that the area where the trees were found had a connection with the sea.
Nural Yilgor1, Aysel Kanturk Figen2 , Sabriye Piskin3
Introduction:
The use of wood polymer composites (WPC) is rapidly increasing all around the world. WPC is produced by mixing wood flour -especially obtained from wastes of wood products industry - with polymers such as low density (LDPE), high density polyethylene (HDPE), polyprophylene (PP), etc. The major advantages of WPC are high resistance to water absorbancy and the high durability against microorganisms which can easily degrade wood and wood based materials. As a consequence, WPC are used in a large variety of structural and non-structural applications, especially for outdoor using such as decking, railing and fencing. In addition, given the fact that recycle and reuse of waste wood products are of both environmental and economical concern, it seems that WPC market will continue to expand in the near future. So it becomes an important task to know the WPC materials` physical, mechanical, biological, thermal and chemical characteristics. The non-uniform composition of material cause problems in analyzing and examining it’s properties. Cryogenic grinding, which is known as freezer milling, was applied in this study to two different types of composite panels which were made of shredded waste beverage boxes and wood polymer composite (WPC) (1,2). While beverage boxes consist of three different components that possess completely different hardening properties- paper, low density polyethylene (LDPE) and aluminium, WPC was composed of industrial wood waste and polyprophylene (PP) (2,4).
All these components vary in terms of their specific surface area, density, micro hardness, hygroscopicity, adsorption and absorption properties. Thermoplastics are also especially difficult to grind to small particle size at room temperature. Therefore, freezer milling was used to eliminate the disadvantages mentioned above (1,2,3,4).
Material and Method:
Cryogenic grinding was performed with two different composite panels for further analyses in FTIR-ATR and thermal analyses instrument. The WPC panels were composed of waste hardwood/softwood mixture and 50% commercialized polypropylene (PP). The other panels were composed of three different materials: cellulose fibers, low density polyethylene and very small amount of aluminium. Before instrumental analysis, cryogenic grinding was applied to both of the panels in order to obtain a homogenous specimens. N2 grinding system parameter is given in Table1. IR spectrums were obtained by using Perkin Elmer 100 FTIR Spectrometer combined with an ATR unit (Universal ATR Diomond Zn/Se) at a resolution of 4 cm-1 for 32 scans in the spectral range 600 to 4000 cm-1. After cryconic grinding, specimens were put in the cell to perform the measurement. Thermal analyse of panel composed of waste beverage cartons was performed using the Perkin Elmer Diamond thermal analyses instrument with pyrolysis characteristics is shown Figure3.
Results and Conclusion
Material properties should be the same at every point for getting a good result in grinding. Any material containing thermoplastics such as WPC can easily be grounded by cyrogenic grinding method. FTIR spectrums of WPC as seen in Fig. 4 and thermal analysis result is shown in Fig. 5. In this study we tried to grind two different types of composite material by freezer mill for further examinations. Fortunately, we obtained a uniform material. It has been shown that freezer milling with liquid nitrogen of composite materials that especially contain thermoplastics provides homogenous specimen.
References
1-Nguyen, T., I. Zarudi, L.C.Zhang, «Grinding-hardening with liquid nitrogen: Mechanism and technology», International Journal of Machine Tools & Manufacture 47 (2007)
2-Yılgör,N, Coşkun Köse, Evren Terzi, Aysel Kantürk Figen, Rebecca Ibach, S. Nami Kartal, and Sabriye Pişkin, “Degradation Behavior and Accelerated Weathering of Composite Boards Produced from Waste Tetra Pak® Packaging Materials”, Bioresources 9 (3), , 2014.
3- Kantürk Figen A., Terzi E., Yilgör N., Kartal S.P., Pişkin S., “ Thermal degradation characteristic of Tetra Pak panel boards under inert atmospher”, The Korean Journal of Chemical Engineering, Vol. 30, Issue 4, pp , (2013).
4- Kartal, S.N., S. Aysal, E. Terzi, N. Yilgor, T. Yoshimura, K. Tsunodo, “Wood and Bamboo-PP Composites: Fungal and Termite Resistance, Water Absorption, and FT-IR Analyses” Bioresources 8 (1), , 2013.
Fig.1. Some images of wood polymer composite samples a a
Figure 2.a) The view of grinding equipment with liquid nitrogen b) Ground wood polymer composite specimen b
CYCLES 2
PRECOOL
6 min
RUN TIME
1:00
COOL TIME
1 min
RATE
9 cps
SETTINGS
Start SCRN
Wood in WPC PP
Table 1. N2 grinding system parameter
Platinium crucible
N2 atm.
10 ºC/dk heating rate
room temperature ºC
WPC
Figure 4. FTIR spectrums of WPC , PP and wood flour
Figure 3. Pyrolysis characteristics of
panels composed of waste beverage cartons
Figure 5. Pyrolysis characteristics of
panels composed of waste beverage cartons
Acknowledgement
This study is supported by Scientific Research Projects Coordination Unit of Istanbul University with project no. UDP
1 Forestry Faculty, Istanbul University, Department of Forest Products Chemistry and Technology, , Istanbul, TURKEY
2 Chemical and Metallurgical Faculty, Yıldız Teknik University, Istanbul, TURKEY
3 Chemical and Metallurgical Faculty, Yıldız Teknik University, Istanbul, Turkey