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JAIST Repository >
i. 北陸先端科学技術大学院大学(JAIST) >
i20. 学位論文 >
M-MS. 修士（マテリアルサイエンス）・修士（材料科学） >
M-MS. 2016年度(H28) >
このアイテムの引用には次の識別子を使用してください:
http://hdl.handle.net/10119/13752
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| タイトル: | Enhancement of glass transition temperature of polar polymer using salt |
| 著者: | Viknasvarri, Ayerdurai |
| 著者（別表記）: | ゔぃくなすゔぁり, あえどぅらい |
| キーワード: | Glass transition temperature
lithium salt
thermal properties |
| 発行日: | Sep-2016 |
| 抄録: | Introduction: Poly(methyl methacrylate) (PMMA) has various attractive properties such as
transparency, mechanical toughness, light weight and good weatherability [1]. Therefore, it is
a candidate as a substitute for inorganic glass especially in the automobile industry due to
high demand for a lightweight vehicle. In order to replace an inorganic glass, however, the
thermal stability must be improved as it has a low glass transition temperature (Tg) (ca.
105 oC). Generally, the introduction of cross-linking and hydrogen bonding is known to
enhance Tg of a polymer. Nevertheless, these methods have disadvantages such as losing
thermoplastic nature. In this study, a salt with low lattice energy is mixed with PMMA by the
solution blend technique. The salt used in this study is well mixed with PMMA and enhances
the Tg without sacrificing the transparency and flowability of the material.
Experiment: PMMA and 5 to 60 wt% of lithium trifluoromethanesulfonate (LiCF3SO3,
LiFMS) or lithium perchlorate (LiClO4) were dissolved in the mixture solvent of
dichloromethane (90 wt%) and methanol (10 wt%) and stirred for 1 hour. The solution was
cast on the Teflon plate and dried at 160 ºC for 30 hours. The obtained mixtures were
compressed into flat sheets with a thickness of 300 μm by a compression-molding machine
for 3 min at 240 ºC under 10 MPa and subsequently cooled at 25 ºC. Tg of the samples was
measured by using a dynamical mechanical analyzer and a differential scanning calorimeter.
3. Results and Discussion: Figure 1 shows Tg, measured by differential scanning
calorimeter of the blends containing various amounts of the salts, in which the salt amount is
expressed by the molar ratio of the lithium to the carbonyl group in PMMA. The result
indicates that the salt addition greatly enhances Tg without scarifying its transparency. The
Tg enhancement is presumably caused by the electrostatic interaction between Li-cation and
carbonyl group in PMMA as indicated in attenuated total reflection results. As a result, the
blends show high Tg. Moreover, all the blends are found to be transparent for PMMA/
LiFMS in the experimental range, while the blends with more than 50 wt% of LiClO4 are
opaque.
4. Conclusion: The Tg enhancement of PMMA was observed by the addition of the lithium
salts. Electrostatic interaction between lithium cation and the carbonyl group is responsible
for the Tg enhancement. |
| 記述: | Supervisor:山口 政之
マテリアルサイエンス研究科
修士 |
| タイトル（英語）: | Enhancement of glass transition temperature of polar polymer using salt |
| 著者（英語）: | Viknasvarri, Ayerdurai |
| 言語: | eng |
| URI: | http://hdl.handle.net/10119/13752 |
| 出現コレクション: | M-MS. 2016年度(H28) (Jun.2016 - Mar.2017)
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