Odor reduction and mechanical properties of natural rubber latex/sepiolite films

The bacterial action on non-rubber components and thermal degradation lead to offensive odor in natural rubber. This study aims to investigate the odor reduction, mechanical and morphological properties of the natural rubber latex (NRL)/sepiolite films with sepiolite from Tolsa (sepiolite-T), and se...

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Main Author: Kok, Lei Bing
Format: Thesis
Language:English
Published: 2019
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Online Access:http://eprints.utm.my/id/eprint/85895/1/KokLeiBingMSChE2019.pdf
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spelling my-utm-ep.858952020-07-30T07:38:29Z Odor reduction and mechanical properties of natural rubber latex/sepiolite films 2019 Kok, Lei Bing TP Chemical technology The bacterial action on non-rubber components and thermal degradation lead to offensive odor in natural rubber. This study aims to investigate the odor reduction, mechanical and morphological properties of the natural rubber latex (NRL)/sepiolite films with sepiolite from Tolsa (sepiolite-T), and sepiolite from China (sepiolite-C). The NRL/sepiolite films were prepared by heating of the NRL and curatives with various sepiolite content, from 0 to 2.0 parts per hundred rubber (phr), in a water bath at 70 ±1 °C. Then, casting the prevulcanized latex onto the glass mold. The results of nitrogen adsorption-desorption isotherms and pore size distribution show that sepiolite-T is a mesoporous material with high specific surface area (Sb e t ) and total pore volume, while sepiolite-C is a macroporous material with low Sb e t and total pore volume. The presence of volatile organic compounds (VOCs) included volatile fatty acids, alcohol, amide, hydrocarbon, terpene, and piperidines in neat NRL films and NRL/sepiolite films has been confirmed by using gas chromatography-mass spectrometry. The results show that the mesoporous sepiolite-T adsorbed more odorous VOCs compared to macroporous sepiolite-C in the neat NRL films. The result of dynamic olfactometry analysis also shows a negative correlation between odor concentration and the sepiolite content. Besides that, the odor concentration of NRL/sepiolite-T samples was much lower than NRL/sepiolite-C samples and the lowest odor concentration was achieved by adding 2.0 phr sepiolite-T (T2.0). The addition of 2.0 phr sepiolite in NRL/sepiolite-T and NRL/sepiolite-C reduced the odor concentration of NRL films by 69.1% and 59.4%, respectively. The morphological studies of NRL/sepiolite films reveal that the defects including sepiolite agglomerate, free volume and sepiolite pull-out were evident in NRL/sepiolite films. It was found that the tendency of defects formation increased with sepiolite content and consequently led to a decrease in tensile strength of NRL/sepiolite films. The rubber/sepiolite interaction in NRL/sepiolite-C films was proven by the ratio of the volume fraction of rubber in unfilled rubber sample to the volume fraction of rubber in a filled rubber sample (Vr/Vf). Therefore, NRL/sepiolite-C films demonstrated a higher tensile strength than NRL/sepiolite-T films. The increase in modulus at 300% elongation (M300) and decrease in elongation at break of NRL/sepiolite films show that the sepiolite provided stiffness to NRL/sepiolite films. The tear strength of NRL/sepiolite-T films was found to increase with sepiolite-T content due to the improvement of crack propagation resistance conferred by sepiolite-T. However, no significant changes of tear strength have been noticed in NRL/sepiolite-C films. Thus it can be concluded that sepiolite-T is a promising deodorizer for NRL films due to its higher odorous VOCs adsorption potentials. However, the high stiffness of the NRL/sepiolite films may not be appropriate for the thin rubber products except T0.5 and T1.0, which has the high elongation at break and low M300. 2019 Thesis http://eprints.utm.my/id/eprint/85895/ http://eprints.utm.my/id/eprint/85895/1/KokLeiBingMSChE2019.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:131605 masters Universiti Teknologi Malaysia, Faculty of Engineering - School of Chemical & Energy Engineering 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
Kok, Lei Bing
Odor reduction and mechanical properties of natural rubber latex/sepiolite films
description The bacterial action on non-rubber components and thermal degradation lead to offensive odor in natural rubber. This study aims to investigate the odor reduction, mechanical and morphological properties of the natural rubber latex (NRL)/sepiolite films with sepiolite from Tolsa (sepiolite-T), and sepiolite from China (sepiolite-C). The NRL/sepiolite films were prepared by heating of the NRL and curatives with various sepiolite content, from 0 to 2.0 parts per hundred rubber (phr), in a water bath at 70 ±1 °C. Then, casting the prevulcanized latex onto the glass mold. The results of nitrogen adsorption-desorption isotherms and pore size distribution show that sepiolite-T is a mesoporous material with high specific surface area (Sb e t ) and total pore volume, while sepiolite-C is a macroporous material with low Sb e t and total pore volume. The presence of volatile organic compounds (VOCs) included volatile fatty acids, alcohol, amide, hydrocarbon, terpene, and piperidines in neat NRL films and NRL/sepiolite films has been confirmed by using gas chromatography-mass spectrometry. The results show that the mesoporous sepiolite-T adsorbed more odorous VOCs compared to macroporous sepiolite-C in the neat NRL films. The result of dynamic olfactometry analysis also shows a negative correlation between odor concentration and the sepiolite content. Besides that, the odor concentration of NRL/sepiolite-T samples was much lower than NRL/sepiolite-C samples and the lowest odor concentration was achieved by adding 2.0 phr sepiolite-T (T2.0). The addition of 2.0 phr sepiolite in NRL/sepiolite-T and NRL/sepiolite-C reduced the odor concentration of NRL films by 69.1% and 59.4%, respectively. The morphological studies of NRL/sepiolite films reveal that the defects including sepiolite agglomerate, free volume and sepiolite pull-out were evident in NRL/sepiolite films. It was found that the tendency of defects formation increased with sepiolite content and consequently led to a decrease in tensile strength of NRL/sepiolite films. The rubber/sepiolite interaction in NRL/sepiolite-C films was proven by the ratio of the volume fraction of rubber in unfilled rubber sample to the volume fraction of rubber in a filled rubber sample (Vr/Vf). Therefore, NRL/sepiolite-C films demonstrated a higher tensile strength than NRL/sepiolite-T films. The increase in modulus at 300% elongation (M300) and decrease in elongation at break of NRL/sepiolite films show that the sepiolite provided stiffness to NRL/sepiolite films. The tear strength of NRL/sepiolite-T films was found to increase with sepiolite-T content due to the improvement of crack propagation resistance conferred by sepiolite-T. However, no significant changes of tear strength have been noticed in NRL/sepiolite-C films. Thus it can be concluded that sepiolite-T is a promising deodorizer for NRL films due to its higher odorous VOCs adsorption potentials. However, the high stiffness of the NRL/sepiolite films may not be appropriate for the thin rubber products except T0.5 and T1.0, which has the high elongation at break and low M300.
format Thesis
qualification_level Master's degree
author Kok, Lei Bing
author_facet Kok, Lei Bing
author_sort Kok, Lei Bing
title Odor reduction and mechanical properties of natural rubber latex/sepiolite films
title_short Odor reduction and mechanical properties of natural rubber latex/sepiolite films
title_full Odor reduction and mechanical properties of natural rubber latex/sepiolite films
title_fullStr Odor reduction and mechanical properties of natural rubber latex/sepiolite films
title_full_unstemmed Odor reduction and mechanical properties of natural rubber latex/sepiolite films
title_sort odor reduction and mechanical properties of natural rubber latex/sepiolite films
granting_institution Universiti Teknologi Malaysia, Faculty of Engineering - School of Chemical & Energy Engineering
granting_department Faculty of Engineering - School of Chemical & Energy Engineering
publishDate 2019
url http://eprints.utm.my/id/eprint/85895/1/KokLeiBingMSChE2019.pdf
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