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Title:	Synthesis of palm-based self-healing polyurethane-lithium perchlorate
Authors:	Wong Chee Sien (P67820)
Supervisor:	Khairiah Haji Badri, Prof. Dr.
Keywords:	Polymerization Polyurethanes
Issue Date:	16-Aug-2018
Description:	Palm-based self-healing polyurethane-LiClO4 (PUC) was synthesized by pre-polymerization method. Self-healing agent namely 6,7-dihydroxycoumarin (DHC) was incorporated into palm-based polyurethane (PU). Blending mixture consisted of palm-based polyol (PKO-p), polyethylene glycol (PEG) and DHC were reacted with 4,4'-methylene diphenyl diisocyanate (MDI) in acetone under nitrogen gas environment at room temperature. Prior to that, lithium perchlorate (LiClO4) salt at 5 %w/w in acetone was added into the blending mixture and the thin film was prepared via solution casting technique. PKO-p and PEG contributed the OH portion while MDI contributed the NCO portion. The studied variables were NCO/OH ratios (200/100, 150/100, 100/100 and 85/100), DHC content (24, 48, 72, 96 ratio to MDI), LiClO4 loading percentage (0, 5, 10, 15, 20, 25 and 30 wt%). The formation of the urethane backbone (NHCO) in the main chain was indicated by the emergence of amine (secondary), carbonyl, carbamate, ether and ester groups in the FTIR spectra. The FTIR spectrum for the self-recovery polyurethane containing NCO/DHC ratio of 200/72 (PU200C72-5) showed increase in transmittance percentage at 830 cm-1 after exposure to ultraviolet (UV) radiation. This is due to the formation of cyclobutane bond in DHC along the polyurethane chain. PUC with inclusion of DHC at NCO/DHC ratios of 200/24 and 200/48 (PU200C24-5 and PU200C48-5 respectively) undergone degradation of the urethane bond indicated upon exposure to UV radiation. Sufficient DHC at NCO/DHC ratios of 200/72 and 200/96 could absorb more UV radiation and prevent degradation of urethane bonds. Glass transition temperature increased from 58 to 68 ° at higher DHC content (NCO/DHC ratios from 200/24 to 200/96 respectively). However, PU200C72-5 showed insignificant difference in the Tg (from 61.0 ° to 61.2°). Micrographs obtained from optical and scanning electron microscopes (SEM) exhibited formation of new layer on top of the scratch wound in PU200C72-5. It is also able to retain its mechanical properties compared to other samples. The electrical conductivity of PU200C72-5 achieved 2.08 × 10-7 S.cm-1. This study showed the potential of self-healing palm-based polyurethane in the production of conductive film for possible application in solar panel manufacturing.,'Certification of Master's/Doctoral Thesis' is not available
Pages:	169
Call Number:	TP1180.P8W646 2018 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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