Sains Malaysiana 47(3)(2018): 571–580

http://dx.doi.org/10.17576/jsm-2018-4703-18

 

Linear Low Density Polyethylene/Poly (Vinyl Alcohol)/Kenaf Composites: Effect of Natural Weathering on Functional Group, Weight Loss Characteristics, Tensile, Morphological and Thermal Properties

(Komposit Polietilena Berketumpatan Rendah Linear/Poli (Vinil Alkohol)/Kenaf: Kesan Pencuacaan Semula Jadi ke atas Kumpulan Fungsian, Pencirian Pengurangan Berat, Sifat Tegangan, Morfologi dan Termal)

 

PANG AI LING¹, HANAFI ISMAIL^2* & AZHAR ABU BAKAR¹

 

¹School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia (USM)

Engineering Campus, 14300 Nibong Tebal, Pulau Pinang, Malaysia

 

²School of Materials and Mineral Resources Engineering, Cluster of Polymer Composites (CPC)

Science and Engineering Research Centre (SERC), Universiti Sains Malaysia (USM)

Engineering Campus, 14300 Nibong Tebal, Pulau Pinang, Malaysia

 

Received: 22 June 2017/Accepted: 5 October 2017

 

ABSTRACT

The development of natural fiber polymer composites is increasing worldwide and in some applications, these composites are used at outdoor rendering them exposed to ultra-violet (UV) radiation. The paper investigates the degradation behavior of linear low density polyethylene/poly (vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites after exposure to different natural weathering durations. The composites with KNF loadings of 10, 20 and 40 parts per hundred resin (phr) were exposed to natural weathering for 3 months and 6 months, respectively. The weathered composites were characterized by Fourier transform infrared (FTIR) spectroscopy, universal testing machine, field emission scanning electron microscopy (FESEM) and differential scanning calorimetry (DSC). The FTIR analysis showed an obvious carbonyl peak in composites after weathering as an evidence of oxidation. The weight loss percentage of composites increased with respect to exposure duration due to higher absorption of UV irradiation. The tensile properties of weathered composites were lower than that of control composites and these properties also decreased with increasing exposure duration. FESEM micrographs illustrated that composites with longer exposure duration suffered more surface damaged. The crystallinity percentage was found to increase with increasing exposure duration.

 

Keywords: Crystallinity; degradation; kenaf (KNF); linear low density polyethylene/poly (vinyl alcohol) (LLDPE/PVOH); natural weathering

 

ABSTRAK

Perkembangan komposit polimer gentian semula jadi semakin bertambah di seluruh dunia dan di dalam penggunaannya, komposit ini banyak digunakan di persekitaran luaran yang terdedah kepada radiasi lampau ungu (UV). Kertas ini melaporkan kelakuan degradasi komposit polietilena berketumpatan rendah linear/poli (vinil alkohol)/kenaf (LLDPE/PVOH/KNF) selepas terdedah kepada tempoh pencuacaan semula jadi yang berbeza. Komposit dengan pembebanan KNF 10, 20, 40 bahagian setiap seratus resin (phr) telah didedahkan kepada pencuacaan semula jadi selama 3 dan 6 bulan. Sampel komposit telah dicirikan dengan spektroskopi transformasi Fourier inframerah, FTIR), mesin pengujianan universal, microskop imbasan elektron berosolusi pancaran medan, FESEM) dan kalorimetri imbasan perbezaan (DSC). Analisis FTIR menunjukkan puncak karbonil yang jelas bagi komposit selepas terdedah kepada pencuacaan yang menunjukkan pengoksidaan telah berlaku. Peratusan kehilangan berat komposit meningkat dengan tempoh pendedahan disebabkan penyerapan sinaran UV. Sifat lenturan komposit yang terdedah kepada pencuacaan lebih rendah berbanding komposit kawalan dan sifat ini juga berkurang dengan peningkatan tempoh pendedahan. Mikrograf FESEM menunjukkan komposit dengan tempoh pendedahan yang lebih panjang mengalami lebih kerosakan morfologi permukaan. Peratusan penghabluran didapati meningkat dengan peningkatan tempoh pendedahan.

 

Kata kunci: Degradasi; kenaf (KNF); pencuacaan semula jadi; penghabluran polietilena berketumpatan rendah linear/poli (vinil alkohol) (LLDPE/PVOH)

REFERENCES

Araoye, B.O., Kasim, A., Abdulwahab, M. & Shehu, U. 2016. Properties evaluation of natural weathered polyester/ nano-locust bean pods ash (LBPA) composite. Industrial Engineering Letters 6: 1-11.

ASTM D3418. 2012. Standard Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential Scanning Calorimetry. West Conshohocken: ASTM International.

ASTM D638. 2010. Standard Test Method for Tensile Properties of Plastics. West Conshohocken: ASTM International.

ASTM D1435. 1999. Standard Practice for Outdoor Weathering of Plastics. West Conshohocken: ASTM International.

Azwa, Z.N., Yousif, B.F., Manalo, A.C. & Karunasena, W. 2013. A review on the degradability of polymeric composites based on natural fibers. Materials and Design 47: 424-442.

Badji, C., Soccalingame, L., Garay, H., Bergeret, A. & Benezet, J.C. 2017. Influence of weathering on visual and surface aspect of wood plastic composites: Correlation approach with mechanical properties and microstructure. Polymer Degradation and Stability 137: 162-172.

Balaji, A. Karthikeyan, B. & Sundar Raj, C. 2014. Bagasse fiber-the future of biocomposite material: A review. International Journal of ChemTech Research 7: 223-233.

Chen, Y., Stark, N.M., Tshabalala, M.A., Gao, J.M. & Fan, Y.M. 2016. Weathering characteristics of wood plastic composites reinforced with extracted or delignified wood flour. Materials 9: 610-621.

Fabiyi, J.S. & McDonald, A.G. 2014. Degradation of polypropylene in naturally and artificially weathered plastic matrix composites. Maderas Ciencia Technology 16(3): 275-290.

Harini, S. & Harsojo. 2014. Effect of combined treatment methods on the crystallinity and surface morphology of kenaf bast fibers. Cellulose Chemistry and Technology 48: 33-43.

Homkhiew, C., Ratanawilai, T. & Thongruang, W. 2014. Effects of natural weathering on the properties of recycled polypropylene composites reinforced with rubberwood flour. Industrial Crops and Products 56: 52-59.

Hung, K.C., Chen, Y.L. & Wu, J.H. 2012. Natural weathering properties of acetylated bamboo plastic composites. Polymer Degradation and Stability 97: 1680-1685.

Husseinsyah, S., Chun, K.S., Yeng, C.M. & Ismail, A. 2016. Tensile, thermal and water absorption properties of corn stalk filled low density polyethylene composites: Effect of coconut oil coupling agent. Sains Malaysiana 45(11): 1733-1739.

Ismail, H., Ahmad, Z., Nordin, R. & Rashid, A. 2009. Processibility and miscibility studies of uncompatibilized linear low density polyethylene/poly (vinyl alcohol) blends. Polymer-Plastics Technology and Engineering 48: 1191- 1197.

Kamal, I., Thirmizir, M.Z., Beyer, G., Saad, M.J., Abdul Rashid, N.A. & Abdul Kadir, Y. 2014. Kenaf for biocomposite: An overview. Journal of Science and Technology 6: 41-66.

Nazrul Islam, M., Dungani, R., Abdul Khalil, H.P.S., Siti Alwani, M. & Wan Nadirah, W.O. 2013. Natural weathering studies of oil palm trunk lumber (OPTL) green polymer composites enhanced with oil palm shell (OPS) nanoparticles. SpringerPlus 2: 592-603.

Nechifor, M. 2016. Factors influencing the photochemical behavior of multicomponent polymeric materials. Photochemical Behavior of Multicomponent Polymeric-based Materials, Advanced Structure Materials 26: 21-65.

Onggo, H. & Pujiastuti, S. 2010. Effect of weathering on functional group and mechanical properties of polypropylene-kenaf composites. Indonesian Journal of Materials Science 11: 123-128.

Pai, A.R. & Japtap, R.N. 2015. Surface morphology & mechanical properties of some unique natural fiber reinforced polymer composites - A review. Journal of Materials and Environmental Science 6: 902-917.

Pang, A.L., Ismail, H., & Abu Bakar, A. 2017. Degradation of linear low-density polyethylene/poly(vinyl alcohol)/kenaf composites. Iranian Polymer Journal DOI: 10.1007/s13726- 017-0555-8.

Pang, A.L., Ismail, H. & Abu Bakar, A. 2016. Tensile properties, water resistance, and thermal properties of linear low-density polyethylene/polyvinyl alcohol/kenaf composites: Effect of 3-(trimethoxysilyl) propyl methacrylate (TMS) as a silane coupling agent. Bioresources 11(3): 5889-5904.

Pang, A.L., Ismail, H. & Abu Bakar, A. 2015. Effects of kenaf loading on processability and properties of linear low-density polyethylene/poly (vinyl alcohol)/kenaf composites. Bioresources 10(4): 7302-7314.

Pickering, K.L., Aruan, M.G. & Le, T.M. 2016. A review of recent developments in natural fiber composites and their mechanical performance. Composites: Part A 83: 98-112.

Sam, S.T., Hani, N. & Ismail, H. 2015. The effect of epoxidized natural rubber (ENR 50) as a compatibilizer on spear grass filled low density polyethylene/soya spent powder. Sains Malaysiana 44(6): 787-792.

Sam, S.T., Ismail, H. & Abdul Khalil, H.P.S. 2013. Degradation of epoxidized natural rubber compatibilized linear low density polyethylene/soya powder blends: The effect of natural weathering. Journal of Polymer Engineering 33(7): 579-588.

Sarifuddin, N., Ismail, H. & Ahmad, Z. 2014. Incorporation of kenaf core fibers into low density polyethylene/thermoplastic sago starch blends exposed to natural weathering. Molecular Crystal and Liquid Crystal 603: 180-193.

Silva, C.B., Martins, A.B., & Catto, A.L. 2017. Effect of natural ageing on the properties of recycled polypropylene/ethylene vinyl acetate/wood flour composites. Revista Materia 22(2): 11835-11851.

Spinace, M.A.S. & De Paoli, M.A. 2015. Biocomposite of a multilayer film scrap and curaua fibers: Preparation and environmental degradation. Journal of Thermoplastic Composite Materials 2015: 1-16.

Zaaba, N.F., Ismail, H. & Mariatti, J. 2015. A study of the degradation of compatibilized and uncompatilized peanut shell powder/recycled polypropylene composites due to natural weathering. Journal of Vinyl and Additive Technology DOI: 10.1002/vnl.21504.

 

 

*Corresponding author; email: ihanafi@usm.my