저작자표시-비영리-변경금지 2.0 대한민국 이용자는 아래의 조건을 ...

More documents

Recommendations

Info

A nanoscale filler dispersed in a polymer matrix can act as a nucleation agent during the foaming process, resulting decreased cell size and increased cell density. [18,19] Also, the cell morphology, which depends strongly on the interaction with the reinforced-filler, is related with the properties such as lightweight, high specific strength, poor heat conductivity, and good isolation to sound. And, several groups have developed physical and chemical foaming methods and investigated the properties of the final foams. Nam et al. prepared PP/clay nanocomposite foams by using a supercritical CO2 in the autoclave. Their products exhibited the homogeneity in cell size of 30 ~ 120 μm, the high cell density of about 10 7 ~ 10 8 cell/mL, and the high cell wall thickness of 5 ~ 15 μm. The clay particles also induced the improvement of the strength of foam in mechanical properties. Di et al. reported PLA/organoclay nanocomposite foams formed by using the mixture of CO2 and N2. The improvements of viscous and elastic properties for PLA/clay nanocomposites allowed them to produce PLA foams with much smaller cell size and higher cell density than those of pure PLA even at low clay content. With supercritical CO2 via the batch foaming process, CNFs and CNTs have been used to prepare PS nanocomposite foams by Shen et al. They compared the nucleation 3
efficiency of different particles, suggesting that CNFs exhibited an excellent nucleation effect due to its food dispersion in the polymer matrix, as well as the favorable wettability and surface curvature in that foaming process. On the contrary, using a chemical blowing agent, Guan et al. manufactured the poly(propylene carbonate) (PPC) foams with a blowing ratio of 16. The decomposition behavior of the blowing agent was investigated, and the effect of blowing agent content and [20-24, 36] the foaming condition on the foaming of PPC studied. Recently, synthetic petroleum-based polymers have caused serious environmental problems due to their limited degradation. For this reason, biodegradable polymers have drawn substantial attention owing to environmental concerns. Among these polymers, biodegradable aliphatic polyester types, i.e., poly(ε-caprolactone) (PCL), poly(lactic acid) (PLA), poly(3-hydroxybutyrae) (PHB) and poly(butylene succinate) (PBS), have currently been the focus of much attention. [25-30] However, they lack price competitiveness and a practically acceptable level of processability, and their usage is due to relatively poor physical properties in particular. Therefore, the incorporation of nanoscale fillers into biodegradable aliphatic polyesters has been studied by many research groups with the aim of 4
Page 1 and 2: 저작자표시-비영리-변경금
Page 3 and 4: 工學碩士學位論文 Pol
Page 5 and 6: Abstract Recently, due to the envir
Page 7 and 8: 국 문 요 약 최근 비분해성
Page 9 and 10: CONTENTS Abstract ……………
Page 11 and 12: SECTION I. LIST OF TABLES Table 1 M
Page 13 and 14: SECTION II. Figure 1 TGA thermogram
Page 15: matrix. However, CNTs are strongly
Page 19 and 20: 2. 1. Materials 2. Experimental The
Page 21 and 22: epresent the mass fraction of MWNTs
Page 23 and 24: The foam density was measured by a
Page 25 and 26: compared with Figure 2c. Therefore,
Page 27 and 28: decreased slightly but increased gr
Page 29 and 30: 3. 5. Foam behaviors and cell geome
Page 31 and 32: Figure 9 illustrates the variation
Page 33 and 34: mixing, and solution blending. Furt
Page 35 and 36: [11] Kannan Balasubramanian, Marko
Page 37 and 38: [28] Lakshmi S. Nair, Cato T. Laure
Page 39 and 40: SECTION II. Preparation and Charact
Page 41 and 42: chemical blowing agent, and to char
Page 43 and 44: vacuo at 60 ºC for 6 h to remove a
Page 45 and 46: were at least performed for each na
Page 47 and 48: nanocomposites enhanced greatly wit
Page 49 and 50: phr CBA loading was observed via op
Page 51 and 52: 3 the density of neat PBS (1.268 g/
Page 53 and 54: 5. References [1] D. Klempner and K
Page 55 and 56: SECTION I. Processing of Poly(butyl
Page 57 and 58: Table 2 Temperature and CBA content
Page 59 and 60: Figure 2 SEM images of the PBS nano
Page 61 and 62: Figure 4 DSC traces of the PBS nano
Page 63 and 64: Figure 6 Optical micrographs of PBS
Page 65 and 66: Figure 8 Blowing ratio of PBS nanoc
Page 67 and 68:
Figure 2 The effect of CNFs content
Page 69 and 70:
Figure 4 The effect of blowing time
Page 71:
Figure 6 Cell size distribution of
show all

저작자표시-비영리-변경금지 2.0 대한민국 이용자는 아래의 조건을 ...

Create successful ePaper yourself

Delete template?

Save as template?