Sains Malaysiana 42(6)(2013): 811–818

Fire-retardant Polyester Composites from Recycled Polyethylene Terephthalate (PET)

Wastes Reinforced with Coconut Fibre

(Komposit Poliester Perencat Api Berasaskan Bahan Buangan PET Kitar Semula

Diperkuat Serabut Kelapa)

Nurul Munirah Abdullah & Ishak Ahmad*

School of Chemical Sciences and Food Technology, Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Diserahkan: 28 Mei 2012/Diterima: 2 Oktober 2012

ABSTRACT

Coconut fibre reinforced composite was prepared by blending unsaturated polyester resin (UPR) from waste PET with 0.3 v% of coconut fibre. The coconut fibres were pre-treated with sodium hydroxide followed by silane prior to inclusion into the UPR. The untreated coconut fibres reinforced composite were used as a control. Dricon® as a phosphate type of flame retardant was then added to the composite to reduce the flammability of the composite. The amount of Dricon® was varied from 0 to 10 wt% of the overall mass of resin. The burning properties and limiting oxygen index (LOI) of the treated and untreated composites increased with the addition of Dricon®. The tensile strength and modulus of both composites were also increased with the addition of Dricon®. The treated fibre composite with 5 wt% Dricon® showed the highest burning time and LOI with the values of 101.5 s and 34 s, respectively. The optimum tensile strength and modulus for treated fibre composite was at 5 wt% Dricon® whereas the untreated fibre composite was at 2.5 wt% loading of Dricon®. Thermogravimetry (TGA) analysis indicated that the degradation temperature increased with the addition of Dricon® up to 5 wt% into UPR/coconut fibre composites. Morphological observations indicated better distribution of Dricon® for treated fibre composite resulted in enhancement of the tensile properties of the treated fibre composite.

Keywords: Coconut fiber; flame retardant; polyester; polyethylene terephthalate

ABSTRAK

Komposit diperkuat serabut kelapa disediakan dengan mengadunkan resin poliester tak tepu (UPR) daripada bahan buangan PET pada komposisi 0.3% isi padu serabut kelapa. Pra-rawatan serabut kelapa telah dilakukan menggunakan natrium hidroksida diikuti oleh silana sebelum dicampurkan ke dalam UPR. Komposit diperkuat serabut kelapa tanpa rawatan telah digunakan sebagai kawalan. Dricon® iaitu sejenis perencat api fosfat kemudiannya ditambah kepada komposit untuk mengurangkan kebolehbakaran komposit. Komposisi Dricon® telah divariasi antara 0-10% berat jisim keseluruhan resin. Sifat pembakaran dan indeks pengehadan oksigen (LOI) bagi komposit terawat dan tanpa rawatan didapati telah meningkat dengan penambahan Dricon®. Kekuatan regangan dan modulus kedua-dua komposit juga telah meningkat dengan penambahan Dricon®. Komposit yang diperkuat serabut terawat dengan 5% berat Dricon® menunjukkan masa pembakaran dan LOI yang tertinggi dengan nilai 101.5 s dan 34 s masing-masing. Kekuatan regangan dan modulus yang optimum bagi komposit dengan serabut terawat adalah pada 5% berat Dricon® manakala komposit dengan serabut tidak terawat adalah pada 2.5% berat Dricon®. Analisis termogravimetri (TGA) menunjukkan bahawa suhu degradasi meningkat dengan penambahan Dricon® sehingga 5% berat yang ditambah ke dalam komposit UPR/serabut kelapa. Pemerhatian morfologi menunjukkan penyebaran Dricon® yang lebih baik bagi komposit dengan serabut yang dirawat menyebabkan peningkatan sifat regangan komposit.

Kata kunci: Kerintangan api; poliester; polietilena tereftalat; serabut kelapa

RUJUKAN

Abu Bakar, D.R., Ahmad, I. & Ramli, A. 2006. Chemical recycling of PET waste from soft drink bottles to produce a thermosetting polyester resin. Malaysia Journal of Chemistry 8(1): 022-026.

Ahmad, I., Mosadeghzad, Z., Daik, R., Ramli, A. 2008. The effect of alkali treatment and filler size on the properties of sawdust/UPR composites based on recycled PET wastes. Journal of Applied Polymer Science 109: 3651-3658.

Atta, A.M., Nassar, I.F. & Bedawy, H.M. 2007. Unsaturated polyester resins based on resin maleic anhydride adduct as corrosion protections of steel. Reactive & Functional Polymers 67: 617-626.

Chen, D.Q., Wang, Y.Z., Hu, X.P., Wang, D.Y., Qu, M.H. & Yang, B. 2005. Flame retardant and anti-dripping effects of a Novel char-forming flame retardant for the treatment of poly(ethylene terephthalate) fabrics. Polymer Degradation and Stability 88: 349-356.

Chong, E.L., Ahmad, I., Dahlan, H.M., Abdullah, I. 2010. Reinforcement of natural rubber/high density polyethylene blends with electron beam irradiated liquid natural rubber-coated rice husk. Radiation Physics and Chemistry 79: 906-911.

Dvir, H., Gottlieb, M., Daren, S. & Tartakovsky, E. 2003. Optimization of a flame retarded polypropylene composite. Composites Science and Technology 63: 1865 1875.

Farias, M.A., Farina, M.Z., Pezzin, A.P.T. & Silva, D.A.K. 2009. Unsaturated polyester composites reinforced with fibre and powder of Peach Palm: Mechanical characterization and water absorption profile. Materials Science and Engineering C 29: 510-513.

Lewin, M. 2005 Unsolved problems and unanswered questions in flame retardance of polymers. Polymer Degradation and Stability 88: 13-19.

Roth, M., Schwarzinger, C., Mueller, U. & Schmidt, H. 2007. Determination of reaction mechanism and evaluation of flame retardants in wood-melamine resin composites. Journal of Analytical and Applied Pyrolysis 79: 306-312.

Shih, Y., Wang, Y., Jeng, R. & Wei, K. 2004. Expandable graphite systems for phosphorus-containing unsaturated polyesters I. Enhanced thermal properties and flame retardancy. Polymer Degradation and Stability 86: 339-348.

Suardana, N.P.G., Piao, Y. & Lim, J.K. 2011. Mechanical properties of hemp fibres and hemp/PP composites: Effects of chemical surface treatment. Materials Physics and Mechanics 11: 1-8

Suppakarn, N. & Jarukumjorn, K. 2009. Mechanical properties and flammability of sisal/PP composites: Effect of flame retardant type and content. Composites: Part B 40: 613-618.

Tan, C., Ahmad, I., Heng, M. 2011. Characterization of polyester composites from recycled polyethylene terephthalate reinforced with empty fruit bunch fibers. Materials and Design 32: 4493-4501.

Vargas, A.F., Orozco, V.H., Rault, F., Giraud, S., Devaux, E. & Lopez, B.L. 2010. Influence of fibre-like nanofillers on the rheological, mechanical, thermal and fire properties of polypropylene: An application to multifilament yarn. Composites: Part A: 1797-1806.

Yang, W., Hu, Y., Tai, Q., Lu, H., Song, L. & Yuen, R.K.K. 2011. Fire and mechanical performance of nanoclay reinforced glass-fibre/PBT composites containing aluminium hypophosphite particles. Composites: Part A 42: 794-800.

*Pengarang untuk surat-menyurat; email: gading@ukm.my