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enhancing the physical properties of the polyesters. [31-35] Poly(butylene succinate) (PBS) is a biodegradable aliphatic polyester resin synthesized by a condensation reaction between 1, 4-butandiol and succinic acid, which has a high fusion temperature (115 o C), remarkable biodegradation, and outstanding processability by means of the extruder used for polyolefins. [26,29] However, it is known that its tensile property, gas barrier properties, melt viscosity for further processing and so on are deficient in various end-use applications. [27] In this study, three different nanocomposite fabrication approaches such as solution blending, melt mixing and the SOAM method were applied to compare the degree of dispersion of MWNTs in the PBS domain. Herein, we have mainly focused on the SOAM method because it can achieve a much better MWNTs dispersion by melt- mixing the nanocomposite prepared by solution blending, under strong shear force. In order to verify the reinforcing effect of MWNTs as compared to neat PBS, as well as to establish the optimal conditions for expanding nanocomposites, the thermal and mechanical properties were investigated. We obtained PBS nanocomposite foams with a closed-cell structure using a chemical blowing agent and characterized the foam behavior. 5
2. 1. Materials 2. Experimental The Poly(butylene succinate)(PBS) used in this study was Enpol G4560 (MI = 1.5 g/10 min) from Ire Chemical LTD., Korea. MWNTs (HollowCNT 75L, purity of higher than 95%, inner/outer diameter distribution 30~50 / 60~80 nm) were purchased from Nanokarbon Co., LTD., Korea. A high purity treatment using HCl and a density treatment were applied according to the manufacturer’s instructions. Chloroform was used as a solvent in the solution blending step and was supplied by Dongyang chemical, Korea. Cellecom ACP-4 acted as a chemical blowing agent (CBA) and was obtained by Kumyang Co., Korea. All materials were used without further purification. 2. 2. Preparation of polymer nanocomposites In this work, three approaches were employed to evaluate the dispersion of MWNTs in the PBS matrix: solution blending, melt mixing, and the SOAM method (solution blending and subsequent melt mixing), respectively. PBS pellets and MWNTs were dried in a vacuum oven at 60 o C for 24 h prior to being used. First, in the case of solution 6
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 and 16: matrix. However, CNTs are strongly
Page 17: efficiency of different particles,
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
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