Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide

Hydroxyl terminated liquid epoxidized natural rubber (HTLENR) was synthesized via an oxidative degradation of liquid epoxidized natural rubber (LENR) in the presence of cobalt acetylacetonate as an oxidizing agent. The subsequent treatment was conducted using sodium borohydride as a reducing agent f...

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Main Author: Md. Basheer Khan, Aina Shafinaz
Format: Thesis
Language:English
Published: 2020
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Online Access:http://eprints.utm.my/id/eprint/92045/1/AinaShafinazMSChE2020.pdf.pdf
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spelling my-utm-ep.920452021-08-30T04:17:33Z Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide 2020 Md. Basheer Khan, Aina Shafinaz TP Chemical technology Hydroxyl terminated liquid epoxidized natural rubber (HTLENR) was synthesized via an oxidative degradation of liquid epoxidized natural rubber (LENR) in the presence of cobalt acetylacetonate as an oxidizing agent. The subsequent treatment was conducted using sodium borohydride as a reducing agent for the formation of hydroxyl group. In order to obtain a low molecular weight of HTLENR, the reaction times were varied for 1 h, 4 h, 7 h, 10 h, and 24 h. Gel permeation chromatography was used to determine the molecular weight of HTLENR. The lowest molecular weight was achieved after 24 h reaction where Mw and Mn were 21869 g/mol and 3233g/mol, respectively. However, HTLENR prepared for 10 h reaction time with Mw and Mn of 37545 g/mol and 3879 g/mol, respectively was chosen as an optimum parameter for further reaction due to the economic factor as well as based on the highest rate of chain scission. The molecular structure of HTLENR was analyzed using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). The appearance of broad peak around 3250 - 3550 cm-1 in FTIR spectrum after the reaction confirmed the existence of OH group in the prepared HTLENR and the peak intensity increased as the reaction time increased. The NMR analysis confirmed the highest hydroxyl content was achieved at 10 h reaction with the amount of approximately 7.56%. HTLENRs with different graphene oxide (GO) loadings (1%, 5% and 10% w/w) were produced by grafting reaction. The FTIR analysis showed a broad peak of OH in HTLENR-g-GO at higher amount of GO loading. Meanwhile, the differential scanning calorimetric analysis revealed the increase of glass transition temperature as the amount of GO in the HTLENR-g-GO increased. Thermal stabilities of HTLENRs were analyzed by thermogravimetric analysis which showed that at 1 wt% and 5 wt% of GO loadings give a higher decomposition temperature compared to the 10 wt% GO loading. Degree of grafting was calculated to be 40.56% at 5 wt% of GO loading and remained almost constant at 10% of GO loading. Based on the result obtained, it can be concluded that HTLENR was successfully produced with the optimum degree of grafting at 5 wt% GO loading. 2020 Thesis http://eprints.utm.my/id/eprint/92045/ http://eprints.utm.my/id/eprint/92045/1/AinaShafinazMSChE2020.pdf.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:139034 masters Universiti Teknologi Malaysia Faculty of Engineering - School of Chemical & Energy Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic TP Chemical technology
spellingShingle TP Chemical technology
Md. Basheer Khan, Aina Shafinaz
Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
description Hydroxyl terminated liquid epoxidized natural rubber (HTLENR) was synthesized via an oxidative degradation of liquid epoxidized natural rubber (LENR) in the presence of cobalt acetylacetonate as an oxidizing agent. The subsequent treatment was conducted using sodium borohydride as a reducing agent for the formation of hydroxyl group. In order to obtain a low molecular weight of HTLENR, the reaction times were varied for 1 h, 4 h, 7 h, 10 h, and 24 h. Gel permeation chromatography was used to determine the molecular weight of HTLENR. The lowest molecular weight was achieved after 24 h reaction where Mw and Mn were 21869 g/mol and 3233g/mol, respectively. However, HTLENR prepared for 10 h reaction time with Mw and Mn of 37545 g/mol and 3879 g/mol, respectively was chosen as an optimum parameter for further reaction due to the economic factor as well as based on the highest rate of chain scission. The molecular structure of HTLENR was analyzed using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). The appearance of broad peak around 3250 - 3550 cm-1 in FTIR spectrum after the reaction confirmed the existence of OH group in the prepared HTLENR and the peak intensity increased as the reaction time increased. The NMR analysis confirmed the highest hydroxyl content was achieved at 10 h reaction with the amount of approximately 7.56%. HTLENRs with different graphene oxide (GO) loadings (1%, 5% and 10% w/w) were produced by grafting reaction. The FTIR analysis showed a broad peak of OH in HTLENR-g-GO at higher amount of GO loading. Meanwhile, the differential scanning calorimetric analysis revealed the increase of glass transition temperature as the amount of GO in the HTLENR-g-GO increased. Thermal stabilities of HTLENRs were analyzed by thermogravimetric analysis which showed that at 1 wt% and 5 wt% of GO loadings give a higher decomposition temperature compared to the 10 wt% GO loading. Degree of grafting was calculated to be 40.56% at 5 wt% of GO loading and remained almost constant at 10% of GO loading. Based on the result obtained, it can be concluded that HTLENR was successfully produced with the optimum degree of grafting at 5 wt% GO loading.
format Thesis
qualification_level Master's degree
author Md. Basheer Khan, Aina Shafinaz
author_facet Md. Basheer Khan, Aina Shafinaz
author_sort Md. Basheer Khan, Aina Shafinaz
title Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
title_short Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
title_full Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
title_fullStr Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
title_full_unstemmed Synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
title_sort synthesis and characterization of hydroxyl terminated liquid epoxidized natural rubber grafted graphene oxide
granting_institution Universiti Teknologi Malaysia
granting_department Faculty of Engineering - School of Chemical & Energy Engineering
publishDate 2020
url http://eprints.utm.my/id/eprint/92045/1/AinaShafinazMSChE2020.pdf.pdf
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