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 ISMAIL2* & 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)

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*Corresponding author; email: ihanafi@usm.my

 

 

 

 

 

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