Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation

Nowadays, the green aspects of the ultraviolet (UV) curing technology have been extensively explored in order to make the technology more energy-efficient and more environmental-friendly. The elimination of mercury, low energy consumption and low operation cost make the ultraviolet light emitting di...

Full description

Saved in:

Bibliographic Details
Main Author:	Ghazali, Siti Khairunisah
Format:	Thesis
Language:	English
Published:	2017
Subjects:	TP Chemical technology
Online Access:	http://eprints.utm.my/id/eprint/77921/1/SitiKhairunisahGhazaliMFChE20171.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.77921
record_format	uketd_dc
spelling	my-utm-ep.779212018-07-18T07:36:42Z Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation 2017-03 Ghazali, Siti Khairunisah TP Chemical technology Nowadays, the green aspects of the ultraviolet (UV) curing technology have been extensively explored in order to make the technology more energy-efficient and more environmental-friendly. The elimination of mercury, low energy consumption and low operation cost make the ultraviolet light emitting diode (UV-LED) system seem to be a promising alternative. Nevertheless, the UV-LED system also has several challenges such as limited photoinitiators and surface cure issues. Therefore, it would be necessary to reformulate the coating composition to match the irradiation profile of UV-LED. In this study, UV-curable coating was formulated based on aliphatic urethane acrylate oligomer (BOMAR™ 7432-GB), 2-ethylhexyl acrylate, methyl methacrylate, trimethylolpropane triacrylate and commercial photoinitiators (Chivacure® 300 and Irgacure® 184). The feasibility of the UV-LED system to replace conventional UV-mercury method was first conducted by comparing its curing behaviours with respect to irradiation time. From the Fourier transform infra-red (FTIR) spectra obtained, the C=C absorption peak observed at 1635 cm-1 and 810 cm-1 were found to be decreasing upon UV irradiation indicating the proceeding of photopolymerisation. A non-tacky coating was achieved after 25 minutes of curing and the degree of conversion and gel fraction measurement were 98% and 95%, respectively indicating that the photopolymerisation via UV-LED is superior to UV-mercury. Since UV-LED system showed promising results in parallel with its inherently environmental friendly (mercury-free) nature, the hydrophobic UV-curable coating was prepared with the sufficient curing time of 25 minutes. One of the strategies to create hydrophobic surface is to reduce its surface free energy (SFE) by incorporating heptadecafluorodecyl methacrylate monomer (HDFDMA). The presence of fluorine group in the hydrophobic coating was examined by FTIR and nuclear magnetic resonance analysis. It is well accepted that fluorine-based material can change the surface wettability due to its exceptionally low SFE. The water contact angle of the coating evolved from 88.4° to 121.2° as the HDFDMA content increased which in turn, reducing the calculated SFE from 32.85 mJ/m2 to 9.68 mJ/m2. Scanning electron microscopy and atomic force microscopy confirmed the migration of the fluorine component towards the coating surface as it is the key factor that contributes to the hydrophobicity. However, the transparency of the cured coating dropped markedly with increasing HDFDMA content. Analogously, these results may attain various potential applications such as liquid-repellent coating and anti-fouling coating. In conclusion, the utilisation of UV-LED in this research was a great initiative to develop green aspect for photopolymerisation 2017-03 Thesis http://eprints.utm.my/id/eprint/77921/ http://eprints.utm.my/id/eprint/77921/1/SitiKhairunisahGhazaliMFChE20171.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:105152 masters Universiti Teknologi Malaysia, Faculty of Chemical and Energy Engineering Faculty of Chemical and Energy Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TP Chemical technology
spellingShingle	TP Chemical technology Ghazali, Siti Khairunisah Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
description	Nowadays, the green aspects of the ultraviolet (UV) curing technology have been extensively explored in order to make the technology more energy-efficient and more environmental-friendly. The elimination of mercury, low energy consumption and low operation cost make the ultraviolet light emitting diode (UV-LED) system seem to be a promising alternative. Nevertheless, the UV-LED system also has several challenges such as limited photoinitiators and surface cure issues. Therefore, it would be necessary to reformulate the coating composition to match the irradiation profile of UV-LED. In this study, UV-curable coating was formulated based on aliphatic urethane acrylate oligomer (BOMAR™ 7432-GB), 2-ethylhexyl acrylate, methyl methacrylate, trimethylolpropane triacrylate and commercial photoinitiators (Chivacure® 300 and Irgacure® 184). The feasibility of the UV-LED system to replace conventional UV-mercury method was first conducted by comparing its curing behaviours with respect to irradiation time. From the Fourier transform infra-red (FTIR) spectra obtained, the C=C absorption peak observed at 1635 cm-1 and 810 cm-1 were found to be decreasing upon UV irradiation indicating the proceeding of photopolymerisation. A non-tacky coating was achieved after 25 minutes of curing and the degree of conversion and gel fraction measurement were 98% and 95%, respectively indicating that the photopolymerisation via UV-LED is superior to UV-mercury. Since UV-LED system showed promising results in parallel with its inherently environmental friendly (mercury-free) nature, the hydrophobic UV-curable coating was prepared with the sufficient curing time of 25 minutes. One of the strategies to create hydrophobic surface is to reduce its surface free energy (SFE) by incorporating heptadecafluorodecyl methacrylate monomer (HDFDMA). The presence of fluorine group in the hydrophobic coating was examined by FTIR and nuclear magnetic resonance analysis. It is well accepted that fluorine-based material can change the surface wettability due to its exceptionally low SFE. The water contact angle of the coating evolved from 88.4° to 121.2° as the HDFDMA content increased which in turn, reducing the calculated SFE from 32.85 mJ/m2 to 9.68 mJ/m2. Scanning electron microscopy and atomic force microscopy confirmed the migration of the fluorine component towards the coating surface as it is the key factor that contributes to the hydrophobicity. However, the transparency of the cured coating dropped markedly with increasing HDFDMA content. Analogously, these results may attain various potential applications such as liquid-repellent coating and anti-fouling coating. In conclusion, the utilisation of UV-LED in this research was a great initiative to develop green aspect for photopolymerisation
format	Thesis
qualification_level	Master's degree
author	Ghazali, Siti Khairunisah
author_facet	Ghazali, Siti Khairunisah
author_sort	Ghazali, Siti Khairunisah
title	Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
title_short	Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
title_full	Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
title_fullStr	Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
title_full_unstemmed	Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
title_sort	preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation
granting_institution	Universiti Teknologi Malaysia, Faculty of Chemical and Energy Engineering
granting_department	Faculty of Chemical and Energy Engineering
publishDate	2017
url	http://eprints.utm.my/id/eprint/77921/1/SitiKhairunisahGhazaliMFChE20171.pdf
_version_	1747817863460159488

Preparation and characterisation of hydrophobic ultraviolet-curable fluorinated polyurethane acrylate using ultraviolet-light emitting diode photopolymerisation

Similar Items