Synthesis And Property Studies Of Methacrylate Based Poly(Siloxane-Silsesquioxane) Resins

• Main Author: Loh , Tat Chuang
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: T Technology; TN263-271 Mineral deposits. Metallic ore deposits. Prospecting
• Online Access: http://eprints.usm.my/41612/1/Synthesis_And_Property_Studies_Of_Methacrylate_Based_Poly%28Siloxane-Silsesquioxane%29_Resins.pdf; http://eprints.usm.my/41612/
• Institution: Universiti Sains Malaysia

Polisiloksan kini telah digunakan sebagai kanta optik, pengkapsulan optoelektronik dan bahan elektronik dalam industri elektronik. HB LED (diod pemancar cahaya kecerahan tinggi) adalah lampu yang berpotensi untuk menggantikan mentol pijar, neon dan halogen. Untuk meningkatkan kecekapan HB LED ini, bahan berasaskan polisiloksan untuk pengkapsulan atau kanta LED memerlukan reka bentuk optik yang baik, pelesapan haba yang baik, indek biasan yang tinggi untuk kecekapan pengekstrakan cahaya dan pemancaran cahaya yang cemerlang, serta rintangan cahaya dan kekerasan yang tinggi untuk melindungi LED daripada tekanan mekanikal. Resin silikone yang biasanya digunakan dalam pengkapsulan LED atau pembungkusan hanya mempunyai indeks biasan 1.40-1.54, kekerasan dan kestabilan terma yang rendah. Dalam kajian ini, bahan hibrid metakrilat poli(silsesquiosan-siloksan) (PSSQ) yang mempunyai kestabilan haba dan indeks biasan yang tinggi (>1.55) telah dihasilkan dan dicadangkan sebagai bahan yang berpotensi untuk pengkapsulan LED dan pembungkusan elektronik. Resin PSSQ yang berasaskan metakrilat mengandungi kandungan trisilanolfenil-POSS yang berbeza telah disintesis melalui tindak balas pemeluwapan, diikuti oleh fabrikasi bahan hibrid PSSQ ini melalui tindak balas penambahan. Struktur kimia, berat molekul, sifat optik dan sifat haba bahan hybrid PSSQ tersebut telah diuji oleh Spektroskopi Fourier Transformasi Inframerah (FTIR), 1H-Nuklear Resonans Magnetik (NMR), 29Si-Nuklear Resonans Magnetik (NMR), Kromatografi Permeasi Gel (GPC), Refraktometer Abbe, Spektrofotometer UV/VIS, Durometer, Kalorimeter Pengimbasan Pembezaan (DSC), Analisis Termomekanis (TMA) dan Analisis Termogravimetri (TGA). Spektrum FTIR menunjukkan bahawa resin PSSQ yang disintesis mempunyai tahap pemeluwapan yang tinggi. Bahan hibrid PSSQ yang dihasilkan telah menunjukkan kejelasan optik yang tinggi, dengan pemancaran cahaya lebih daripada 95% dalam linkungan gelombang cahaya 400-1000nm. Kandungan POSS bahan hybrid PSSQ yang tinggi memberi kekerasan yang tingi dan indek biasan yang tinggi. Begitu juga, bahan hibrid PSSQ diperkukuh dengan kandungan POSS yang tinggi menunjukkan kestabilan terma yang baik pada ujian penuaan suhu tinggi, suhu penguraian yang tinggi , serta Tg lebih tinggi. ________________________________________________________________________________________________________________________ Nowadays, polysiloxane is widely used as optical lenses, optoelectronic encapsulation and electronic packaging materials in electronic industry. Typical HB LEDs (high brightness light emitting diodes) is a potential lamp to replace existing incandescent, fluorescent and halogen bulbs. As for development of such high efficiency HB LEDs, the polysiloxane based LED encapsulation materials or lenses requires an excellent optical design, good heat dissipation, high refractive index for maximum light extraction efficiency and excellent light transmittance, as well as light resistance and high hardness to protect the LEDs from mechanical shock. However, most of the commercial silicone resin employed in LEDs encapsulation or packaging is known to have a refractive index range from 1.40 to 1.54 only, low hardness and poor thermal stability. In this research study, thermally stable and high refractive index (>1.55) methacrylate based poly(siloxane-silsesquixoane) (PSSQ) hybrid materials were fabricated and proposed as a potential material for optoelectronic and LEDs packaging materials. The methacrylate based PSSQ resins containing different portion of trisilanolphenyl-POSS were synthesized through condensation reaction, followed by the fabrication of these methacrylate based PSSQ hybrid material through hydrosilylation reaction. The chemical structure, molecular weight, optical properties and thermal properties were investigated by Fourier Transform Infrared (FTIR) Spectroscopy, 29Si-Nuclear Magnetic Resonance (NMR), Gel Permeable Chromatography (GPC), Abbe refractometer, UV/Visible Spectrophotometer, Thermomechanical Analyzer (TMA) and Thermogravimetric Analyser (TGA). The FTIR spectra showed that the synthesized PSSQ resins have high degree of condensation. The fabricated PSSQ hybrid mateirals were shows excellent optical clarity, with light transmittance at least 96% over the wavelength 400 – 1000nm. The PSSQ hybrid material with higher POSS content gives higher hardness and higher refractive index (1.56). Similarly, PSSQ hybrid material with higher POSS content shown excellent thermal stability, high discoloration resistance at high temperature aging test, higher decomposition temperature, higher Tg and lower CTE.