Investrigation on the Surface Property of Poly(imide-siloxane)/Cermaic Composites.

• Main Authors: Hsin-Yi Lai, 賴心怡
• Other Authors: Dr. Rong-Hsien Lin
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/59758327146049064725

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系 === 98 === In this study, the surface properties of films of polyimides and poly(imide-siloxane)s and their respective poly(amic acid)s, and films of composites thereof containing ceramic powders, were evaluated after polymer synthesis and thermal film- forming process . During polymer and composite preparations, 4,4-oxydiphthalic dianhydride (OPDA) was reacted with two kinds of diamine, 2,2-bis(4-(4-aminophen- oxy)phenyl)propane (BAPP) and diaminopolysiloxane (DAPS), at different molar ratio to form poly(amic acid)s. While a variety of ceramic powders at different ratios were added during the poly(amic acid)s formation in case of polymer/ceramic composites preparations. The prepared mixture after reaction used as the coating solution was coated on a flat copper foil. Then, thermal cyclization was conducted to get polyimides and polyimde/ceramic composites in film form. The obtained poly(amic acid)s, polyimides, and its composites can be characterized by infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR) through monitoring the functional group change, by scanning electron microscopy (SEM), optical microscope (OM), and surface roughness meter (SRM) through observing the surface morphology, by thermal gravimetric analyzer (TGA) through measuring the thermal stability and weight of residue. Finally, contact angle analyzer (CAA) can be applied to measure the surface contact angle, and then a two-liquid method and three-liquid method were used respectively to calculate the surface free energy and its components of the films. For the polymers, i.e., poly(amic acid)s, polyimides and poly(imid-siloxane)s, the results showed that the higher the heat treatment temperature of thermal cyclization, the lower the γsp , γs- , γsAB of the films. In addition, the introducing of a siloxane segment into polyimides dramatically lowers the γs and γsp, and also lower the thermal treatment temperature required for fully imidization. However, a overheating thermal treatment temperature will cause the film surface chain degradation and leads to a sudden increasing in γsp. In addition, for the polymer/ceramic powder composites, the results showed the addition of ceramic powders into reaction mixture containing dianhydride and diamine (BAPP/DAPS-248) to proceed an in-situ polymerization of poly (amic acid- siloxane) containing ceramic powders has no significant effect on the polymerization. By surface morphology observation, the addition of powders will cause surface roughness of the composite films with the increase of the powder dosage. Under lower dosages of the powders, the γs of the film increases with powder contents, because the ceramic powders have higher surface free energy than the polymer substrate. But, γs+ was found decreasing, while the powder content was increased. At higher dosages of the powders, an opposite trend was found between the dosage and the surface energy, i.e., the γs of the film decreases with powder contents increasing, while γs+ increases. However, surface morphology observation reveals that furthermore dosage of the powders will cause sufficient degree of surface roughness muffing the contact angle measurements and then the surface energy calculation fluctuation and variability.