Preparation And Properties Of Poly (Vinyl Chloride) Epoxidized Natural Rubber Kenaf Core Powder Composites

Majid, Rohani Abdul (2016) Preparation And Properties Of Poly (Vinyl Chloride) Epoxidized Natural Rubber Kenaf Core Powder Composites. PhD thesis, Universiti Sains Malaysia.

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Abstract

Peningkatan dalam penggunaan komposit polimer bergentian semulajadi telah menarik perhatian, sebagai alternatif persekitaran yang lebih hijau dan pada masa yang sama ia dapat mengurangkan kos pembuatan gentian sintetik. Pada sudut yang berbeza, penyelidikan dalam menghasilkan termoplastik bolehlentur dengan memperkenalkan bahan elastomer, memperlihatkan aliran yang memberangsangkan bagi mempertingkatkan ciri-ciri tertentu sesuatu polimer. Usaha telah dilakukan untuk menghasilkan komposit poli(vinil klorida) (PVC), getah asli terepoksida (ENR) dan serbuk teras kenaf (KCP). Dalam kajian ini, kesan-kesan pembebanan KCP, penserasi, pemvulkanan dinamik dan pengisi terawat kimia terhadap sifat-sifat regangan, morfologi, penyerapan air, pembengkakan, penuaan termo-oksidatif dan termal telah dikaji. Untuk permulaan, PVC/ENR/KCP dengan pembebanan KCP 0 sehingga 20 phr telah disediakan menggunakan pencampuran adunan lebur dan pengacuanan mampatan. Penambahan KCP ke dalam matriks PVC/ENR menunjukkan penurunan kekuatan regangan dan pemanjangan takat putus. Modulus Young pula menunjukkan aliran peningkatan disebabkan penambahan kekakuan oleh KCP di dalam matriks PVC/ENR. Pengurangan kekuatan regangan adalah disebabkan berkurangnya pelekatan antara muka, di antara pengisi dan matriks, yang menyebabkan berkurangnya pemindahan tegasan. Seterusnya, kesan-kesan maleik anhidrida (MA) sebagai penserasi, ke atas sifat-sifat komposit PVC/ENR/KCP telah dikaji. Dua jenis penserasi MA telah digunakan. Didapati, penserasi PE-g-MA dan PVC-g-MA meningkatkan kekuatan regangan dan pemanjangan takat putus. Komposit dengan penserasi PVC-g-MA menunjukkan kekuatan regangan lebih tinggi berbanding komposit dengan penserasi PE-g-MA. Sifat-sifat penuaan termooksidatif PVC/ENR/KCP dengan penserasi PVC-g-MA juga menunjukkan rintangan yang lebih tinggi disebabkan oleh peningkatan interaksi kimia berbanding penserasi PE-g-MA. Kemudian, penambahan sambung silang atau pemvulkanan dinamik menunjukkan sifat-sifat regangan yang lebih tinggi. Pemvulkanan dinamik menggunakan sistem separa efisien telah meningkatkan interaksi antara matrik, di mana pembentukan sambung silang sulfur telah berlaku. Ia juga menunjukkan peningkatan sifat-sifat penuaan termo-oksidatif dengan pemvulkanan dinamik. Seterusnya, perawatan kimia telah diperkenalkan. Perawatan kimia benzoil klorida terhadap komposit PVC/ENR/KCP meningkatkan kekuatan regangan, modulus Young dan pemanjangan takat putus komposit PVC/ENR/KCP. Komposit dengan perawatan kimia benzoil klorida juga telah meningkatkan sifat-sifat penyerapan air disebabkan oleh peningkatan interaksi antara muka. Namun, rintangan terhadap penuaan termo-oksidatif menunjukkan penurunan berbanding PVC/ENR/KCP tanpa perawatan kimia benzoil klorida seawal 3 hari pendedahan. Untuk perawatan kimia menggunakan sodium dodesil sulfat, sedikit peningkatan direkodkan bagi kekuatan regangan, dan peningkatan yang sangat tinggi untuk pemanjangan takat putus. Tidak seperti perawatan kimia benzoil klorida, modulus Young untuk komposit dengan perawatan kimia sodium dodesil sulfat menunjukkan nilai yang lebih rendah berbanding komposit tanpa perawatan kimia. Pemerhatian yang sama seperti komposit dengan perawatan kimia benzoil klorida telah direkodkan untuk sifat-sifat penuaan termo-oksidatif. Keputusan menunjukkan penurunan seawal 3 hari pendedahan. ________________________________________________________________________________________________________________________ An increase in the use of natural fibre-reinforced polymer composites has attracted attention towards a greener environment, and at the same time has reduced the production cost for synthetic fibres. On the other hand, researchers, in their efforts to produce a flexible thermoplastic through the incorporation of elastomeric materials, have also shown a positive trend towards improving certain properties of the polymers. Efforts are currently underway to produce polyvinyl chloride (PVC), epoxidized natural rubber (ENR) and kenaf core powder (KCP) composites. In this study, the effects of KCP loading, compatibilizers, dynamic vulcanization and filler chemical treatment on the tensile, morphological, water absorption and swelling, thermo-oxidative ageing, and thermal properties of a composite were investigated. Firstly, the PVC/ENR/KCP, containing 0 to 20 phr of KCP, was prepared using the melt blending and compression moulding methods. The addition of KCP into the PVC/ENR matrix resulted in a decrease in tensile strength and an elongation at break. The Young’s modulus was observed to increase due to the addition of rigid KCP into the PVC/ENR matrix. The reduction in tensile strength was due to low interfacial adhesion between the filler and the matrix, leading to lower stress transfer. Secondly, the effect of maleic anhydride as a compatibilizer on the properties of the PVC/ENR/KCP composite was studied. Two types of MA compatibilizer were used. It was found that PE-g-MA and PVC-g-MA compatibilizers elevated the tensile strength and elongation at break. The PVC-g-MA compatibilized composites exhibited higher tensile properties compared to the PE-g-MA compatibilized composites. The thermo-oxidative ageing of the PVC/ENR/KCP with PVC-g-MA showed better resistance due to the enhancement in the interfacial adhesion as compared to the PE-g-MA. Later, the incorporation of cross-linking or dynamic vulcanization showed an outstanding improvement in tensile properties. Dynamic vulcanization using a semi-efficient sulphur system improved the matrix-matrix interaction with the sulphur cross-linking bond. It was also observed that thermooxidative ageing improved with dynamic vulcanization. Next, filler treatments were incorporated. The benzoyl chloride treatment improved the tensile strength, Young’s modulus and elongation of the PVC/ENR/KCP composite. The benzoyl chloride treatment was also observed to have improved the water absorption properties due to the enhancement of interfacial adhesion. Unfortunately, there was a reduction in the thermo-oxidative ageing properties as early as after 3 days of exposure. For the sodium dodecyl sulphate-treated composite, there was a slight increase in the tensile strength and an outstanding increase in the elongation at break. Unlike the benzoyl chloride-treated composite, the Young’s modulus for the sodium dodecyl sulphatetreated composite showed a lower value compared to the untreated composite. The same observation as that of the benzoyl chloride-treated composite was recorded for the thermo-oxidative ageing properties. The results indicated that there was a reduction as early as after 3 days of exposure.

Item Type: Thesis (PhD)
Additional Information: Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=3164
Subjects: T Technology
T Technology > TA Engineering (General). Civil engineering (General) > TA404 Composite materials
Divisions: Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Bahan & Sumber Mineral (School of Material & Mineral Resource Engineering) > Thesis
Depositing User: Mr Mohd Jasnizam Mohd Salleh
Date Deposited: 04 Sep 2018 08:59
Last Modified: 04 Sep 2018 08:59
URI: http://eprints.usm.my/id/eprint/41716

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