lojmikak
Dołączył: 30 Sie 2010
Posty: 1597
Przeczytał: 0 tematów
Ostrzeżeń: 0/5
Skąd: olvovw
|
 Wysłany: Czw 20:46, 23 Gru 2010 Temat postu: stivali ugg Imidization process on the BTDA-m-PDA |
 |
|
Imidization process on the BTDA-m-PDA polyimide aggregation structure of
0071 Factory C Figure 6PI-F1 of the DSC curves of Fig. 6DSCofPI-F1 can be seen from Figure 6, this rigid-chain polyimide glass transition temperature of 241c 【=, while the film above the glass transition temperature, that is 300o (=, dealt with 1h, but the DSC curves melting peak is not on, and the diffraction pattern of the film on x only amorphous diffraction peak. This shows that the ordinary two-step molding process polyimide film is amorphous, and only above the glass transition temperature heat treatment is not the film's aggregate structure from amorphous to ordered structure change. Molecular Simulation results show that, BTDA / m-PDA polyimide was rod-like molecular chain conformation, chain section of poor exercise capacity, ordered molecular chain dynamics conditions can be quite harsh. and PI-F2 was carried out by PI-Fl swelling, and then deal with the 300c 【= get,[link widoczny dla zalogowanych], polarizing microscopy and x diffraction test structures show that PI-F2 has a lower ordered. This result shows that the swelling after the polyimide molecular chain increases the free volume between the solvent-assisted molecular chain to improve exercise capacity, at this time then over the glass transition temperature of thin film processing, polyimide molecular chains to some extent be adjusted to produce low-order structure, the film in the polarizing microscope showed cloudy bright field. In addition, the use of Rapid thermal imidization temperature coating process,[link widoczny dla zalogowanych], when the hot stage temperature 200c 【=, the coating of volatile solvent, imidization reaction and ordered structure (crystallization) process of the formation of three at the same time, the three matched in the speed to form the typical morphology of banded spherulites. 2.3 aggregation structure of the film tensile properties are listed in Table 1,[link widoczny dla zalogowanych], respectively, the thermal imidization process of 3 before the swelling of amorphous film PI-Fl and swelling after high temperature treatment with a low degree of order for a film tensile properties of PI. Table 1 Tensile properties of polyimide film Tab.1Ten ~ lepropertiesofPls can be seen from the table, PI- F2 has a higher tensile strength and tensile modulus, tensile strength increased by 7.0%, the tensile modulus increased by 16.8%, while elongation decreased to the original 83.5%. PI -F2 compared with the PI-Fl, PI-F2 in the aggregation structure have demonstrated a low order, while PI-Fl is the amorphous structure. As PI-F2 show a certain orderliness of molecular films a pile of chain more closely, the forces between molecules are stronger, and therefore on the tensile properties show high strength and modulus while reducing elongation. 3 Conclusion 1) BTDA and m-PDA prepared for the monomer polyimide can be crystallized; 2) by changing the imidization process, the process of changing the polyimide polymer in which the dynamic conditions,[link widoczny dla zalogowanych], can aggregate structure of polyimide orderliness of control; 3) Swelling and polyimide films after high temperature treatment, can make the film formation of low-ordered structure of aggregation. Aggregation with low ordering of the structure of amorphous polyimide film and polyimide film structure compared to 7.0% increased the tensile strength and tensile modulus increased by 16.8%, elongation at break growth rate dropped to 83.5%. References: [1] Ding Mengxian, what days of white. Polyimide new materials [M]. Beijing: Science Press, 1998. [2] VanmRatta. Crystallization, morphology, thermalstabilityandadhesivepropertiesofnovelhishperformancesemicrystallinepolyimides [D]. Virginia, USA: ViIliaPolytechnicInstituteandStateUniversity, 1999. [3] MarkVB, ChengYaoyi, PradnyaNagarkart, eta1. MolecularmodelingandstructurestudiesofLARC-CPIsemicrystallinepo] yimlddJ]. Polymer, 1997,38 (12) :3059-3068. [4] He Manjun, Chen Weixiao, Dong West Xia. Polymer Physics [M]. Shanghai: Fudan University Press,[link widoczny dla zalogowanych], 1990. (Edit Huang Xiaochuan) 2468OO2OOOO ● ●
相关的主题文章：
[link widoczny dla zalogowanych]
[link widoczny dla zalogowanych]
[link widoczny dla zalogowanych]
Post został pochwalony 0 razy
|
|
