臺灣博碩士論文加值系統

以H-1 與C-13 NMR定量一系列對苯二甲酸乙酯與對苯二甲酸丙酯共聚酯(PET/PTT)的組成。樣品代號分別為C2，C3，C4，C5，C6，C7和C8代表，其在共聚酯內ET單體的組成個別為8.9，33.7，37.9，50.1，72.5，77.8，和90.8%。由芳香環上四級碳的正規化面積求得共聚酯內單體的排列順序機率。ET單體和PT單體的數量平均順序結構長度範圍由1.0到10.2，亂度參數值為0.96至1.1。由數量平均順序結構長度和亂度參數的結果顯示這些共聚酯為random共聚酯。
以微差掃描卡儀(Differential scanning calorimeter, DSC)探討等溫結晶動力和熔融行為。當共聚酯中的ET單體組成由8.9%(C2)增加至72.5% (C6)，其等溫結晶峰的平均焓值由47 J/g減至28 J/g，而ET單體組成為90.8%時，其等溫結晶峰的平均焓值增加至42 J/g。Avrami 指數n1介於2.03和2.98之間，顯示此主要結晶為二度至三度空間成長的異質成核。在等溫結晶方面，樣品的等溫結晶時間為結晶峰時間(peak time)的9~14倍以確保結晶完成。從10和50°C/min加熱的圖形中，可得到多重熔融吸熱峰。在低結晶溫度時可偵測到三個熔融峰，當結晶溫度增加時，位於中間及最高溫的兩個峰會漸漸合併，最後，在較高的結晶溫度時，三個熔融峰會合併成一單峰。低溫的熔融峰和二級結晶的最後步驟有關。位於中間溫度的熔融峰則和形成主要結晶晶體的熔融特性有關。最高溫的熔融峰可能是由於在加熱過程中熔融再結晶所形成的晶體熔融所造成的。
由50°C/min加熱得到的多峰熔融行為之結果，將其一次晶體的熔融峰溫度對結晶溫度作圖。以Hoffman-Weeks圖求得平衡熔點( )。以結晶一半所需的時間(t1/2)作分析，可得到每一個共聚酯的regime II→III轉移。對樣品代號為C2，C3，C4，C5，C6，C7和C8的( , )數值分別為(237.1，193.6)，(198.9，147.3)，(187.9，140.4)，(226.6，164.8)，(230.1，172.0)和(261.1，208.4)。
最後，在相同的過冷度(supercooling，DT＝ - Tc)下，比較全部的結晶速率(1/ t1/2)。C2樣品在低過冷度下結晶速率最快，C3和C4則有相似的結晶速率。C6樣品在較高的過冷度下結晶且結晶速率最慢。在DT = 50~60°C，C7的結晶速率和C3、C4接近且C7在較高的過冷度下結晶速率較快。當ET單體組成由8.9% (C2)增加至37.9% (C4)時，焓的平均值或結晶度由–47 J/g減低至–32 J/g；當ET單體組成由72.5% (C6)增加至90.8% (C8)時，焓的平均值或結晶度由–28 J/g減低至–42 J/g。此結果顯示主鏈上較少成份的數量和分佈會影響成核速率、成長速率以及共聚酯最後的結晶度。

The compositions of a series of poly (ethylene/trimethylene terephthalate) copolyesters were identified by 1H-NMR and 13C-NMR. The ethylene terephthalate (ET) units are 8.9, 33.7, 37.9, 50.1, 72.5, 77.8, and 90.8% in the copolyesters with sample codes of C2, C3, C4, C5, C6, C7, and C8, respectively. The triad sequence probabilities were determined from the normalized areas of aromatic quaternary carbons. The calculated average-number sequence lengths of ethylene- and trimethylene- terephthalate units range from 1.0 to 10.2 that depends on the relative ratio of both units in the copolymer. The values of randomness parameter for all of these copolyesters are between 0.96 and 1.1. Both values of sequence length and randomness parameter indicate that these copolyesters are random copolymers.
Differential scanning calorimeter (DSC) was used to study the isothermal crystallization kinetics and the melting behaviors at heating rates of 10 and 50°C/min. The average enthalpy of isothermal crystallization (DH) decreased from 47 to 28 J/g when the ET units in the copolymer increased from 8.9% (C2) to 72.5% (C6), and then the enthalpy increased up to 42 J/g for the C8 copolymer with 90.8% of ET units. The results of Avrami analysis yielded one (n1) or two exponents. The n1 values of all of these copolymers were between 2.03 and 2.98. It suggests that the primary crystallization followed a heterogeneous nucleation with two-three dimensional form of growth. While investigating the isothermal crystallization, DSC specimens were crystallized for 9-14 times of the peak time to ensure the completion of crystallization. Both heating curves at 10 and 50°C/min showed multiple endothermic peaks. Triple-melting peaks were detected at lower crystallization temperature (Tc), then the medium and the highest temperature peaks merged gradually to form double-melting peaks with increase in Tc, finally, all three peaks merged together to become a single peak at higher Tc. The low temperature melting peak was associated with the last step of secondary crystallization. The middle temperature melting peak was considered to be characteristic of the melting of the crystals formed in the primary crystallization. The highest temperature melting peak may be due to the melting of crystallite formed by melting and recrystallization during the DSC heating scans.
From the results of multiple melting behaviors at a heating rate of 50°C/min, the melting peak temperatures of primary crystals were plotted versus the crystallization temperature, Tc. The Hoffman-Weeks plot gave an equilibrium melting temperature, . Using the half-time of crystallization (t1/2) for analysis, regime II→III transition was found for each copolyester. The pairs of ( , ) in unit of °C are (237.1, 193.6), (198.9, 147.3), (187.9, 140.4), (226.6, 164.8), (230.1, 172.0), and (261.1, 208.4) for C2, C3, C4, C6, C7, and C8, respectively.
Finally, the overall crystallization rates (1/ t1/2) were compared at equivalent supercooling, DT ( - Tc). The C2 copolyester crystallized the fastest and at lower supercooling. C3 and C4 copolyesters had very similar rates. The C6 copolyester crystallized the slowest and at higher supercooling. At DT = 50~60°C, the rates of C7 were close to those of C3 and C4 copolyesters, then the C7 copolyester crystallized faster at higher supercooling. The average value of DH or crystallinity decreased from –47 to –32 J/g when the minor component, ET unit, increasesd from 8.9% (C2) to 37.9% (C4), and then the crystallinity increased from –28 to –42 J/g as the ET unit increases from 72.5% (C6) to 90.8% (C8). It indicated that the number and the distribution of minor component in the main chain should affect the nucleation rate, the growth rate and the final crystallinity of the copolyesters.

List of Tablesiii
List of Illustrationsv
摘要xi
Abstractxiii
Chapter 1. Introduction1
Chapter 2. Literature Review3
2.1 Copolymer sequence3
2.2 Transesterification5
2.3 Determination of the equilibrium melting temperature by Hoffman-Weeks linear extrapolation5
2.4 Avrami Analysis6
2.5 Hoffman’s nucleation theory7
2.6 Regime transition8
Chapter 3. Experimental11
3.1 Materials11
3.2 Instruments11
3.3 Sample Preparation12
3.3.1 Composition and sequence analysis12
3.3.2 Transesterification12
3.4 Differential Scanning Calorimetry (DSC)12
3.4.1 Melting condition13
3.4.2 Isothermal crystallization13
3.5 Nuclear Magnetic Resonance Spectroscopy (NMR)14
3.6 Copolymer composition and sequence14
3.7 Avrami Analysis15
3.8 Experimental Flow Chart16
Chapter 4 Results and discussion18
4.1 Composition and sequence distribution analysis18
4.2 Transesterification20
4.3 Isothermal crystallization kinetics and melting behavior20
4.3.1Copolyester containing 62.1% trimethylene- and 37.9% ethylene- units
20
4.3.2Copolyester containing 91.1% trimethylene- and 8.9% ethylene- units
24
4.3.3Copolyester containing 66.3% trimethylene- and 33.7% ethylene- units
26
4.3.4Copolyester containing 27.5% trimethylene- and 72.5% ethylene- units
28
4.3.5Copolyester containing 22.2% trimethylene- and 77.8% ethylene- units
30
4.3.6Copolyester containing 9.2% trimethylene- and 90.8% ethylene- units
32
4.4 Comparison of copolyesters with different compositions34
Chapter 5 Conclusion36
References38

1.Tseng, I. M.; Huang, J. C.; Juang, C. Processes for 1,3-Propanediol and Poly(Propylene Terephthalate) Manufacture. Chemical Information Monthly 1998, 12(6), 24-38. (in Chinese)2.Newmark, R. A. Sequence Distribution in Polyethylene/Tetramethylene Terephthalate Copolyesters by 13C-NMR. J. Polym. Sci., Polym. Chem. Edn. 1980, 18, 559-563.3.Kricheldorf, H. R. 13C NMR Sequence Analysis: 17. Investigation on Polyesters from Diacids and Diols. Makromol. Chem. 1978, 179, 2133-2143.4.Yamadera, R.; Murano, M. The Determination of Randomness in Copolyesters by High Resolution Nuclear Magnetic Resonance. J. Polym. Sci., A-1, Polym. Chem. 1967, 5, 2259-2268.5.Aerdts, A. M.; Eersels, K. L. L.; Groeninckx, G. Transamidation in Melt-Mixed Aliphatic and Aromatic Polyamides: 1. Determination of the Degree of Randomness and Number-Average Block Length by Means of 13C NMR. Macromolecules 1996, 29, 1041-1045.6.Backson, S. C. E.; Kenwright, A. M.; Richards, R. W. A 13C NMR Study of the Transesterification in Mixtures of Poly(Ethylene Terephthalate) and Poly(Butylene Terephthalate). Polymer 1995, 36(10), 1991-1998.7.Feng, Y.; Hay, J. N. The Characterisation of Random Propylene-ethylene Copolymer. Polymer 1998, 39(25), 6589-6596.8.Urman, Y. G.; Alekseyeva, S. G.; Slonim, I. Y. 13C-NMR Method for the Study of the Distribution of Monomer Units in Copolyesters. Vysokomol. Soyed. 1977, A19(2), 299-303.9.Lee, K. B.; Kweon, J.; Lee, H. J.; Park, H. A 13C NMR Determination for Monomer Compositions in Ethylene-propylene Copolymers, Ethylene-propylene-Butene-1, and Ethylene-propylene-diene Terpolymers. Polym. J. 1996, 28(8), 696-702.10.Shan, C. R.; Weng, Z. X.; Huang, Z. M.; Pan, Z. R. Studies on the Microstructure of Vinyl/N-phenylmaleimide Copolymers by NMR and Their Applications. J. Appl. Polym. Sci. 2000, 77, 2581-2587.11.Dasgupta, A.; Garnaik, B. Microstructures of Styrene-Acrylamide Copolymers Using 13C NMR Spectroscopy. Polym. J. 1998, 30(12), 956-962.12.Hoffman, J. D.; Weeks, J. J. Melting Process and the Equilibrium Melting Temperature of Polychlorotrifluoroethylene. J. Res. Natl. Bur. Stand. 1962, 66A, 13-28.13.Zhou, C.; Clough, S. B. Multiple Melting Endotherms of Poly(Ethylene Terephthalate). Polym. Eng. Sci. 1988, 28(2), 65-68.14. Lu, X. F.; Hay, J. N. Isothermal Crystallization Kinetics and Melting Behaviour of Poly(Ethylene Terephthalate). Polymer 2001, 42, 9423-9431.15.Huang, J. M.; Chang, F. C. Crystallization Kinetics of Poly (Trimethylene Terephthalate). J. Polym. Sci., Part B, Polym. Phys. 2000, 38, 934-941.16.Hoffamn, J. D.; Davis, G. T.; Lauritzen, J. I., Jr. Crystalline and Noncrystalline Solids. In Treatise on Solid State Chemistry; Hannay, N. B., Eds.; Plenum: New York, 1976; Vol. 3, Chapter 7.17.Lovinger, A. J.; Davis, D. D.; Padden, F. J., Jr. Kinetic Analysis of the Crystallization of Poly(r-Phenylene Sulphide). Polymer 1985, 26, 1595-1604.18.Fatou, J. G.; Marco C.; Mandelkern L. The Influence of Molecular Weight on the Regime Crystallization of Linear Polyethylene. Polymer 1990, 31, 1685-1693.19.Phillips, P. J.; Vatansever, N. Regime Transition in Fractions of cis-Polyisoprene. Macromolecules 1987, 20, 2138-2146.20.Clark, E. J.; Hoffman, J. D. Regime III Crystallization in Polypropylene. Macromolecules 1984, 17, 878-885.21. Hoffman, J. D. Regime III Crystallization in Melt-crystallized Polymers : The Variable Cluster Model of Chain Folding. Polymer 1983, 24, 3-26.22.Hoffman, J. D. Role of Reptation in the Rate of Crystallization of Polyethylene Fractions from the Melt. Polymer 1982, 23, 656-670.23.Tseng, I. M. Synthesis and Characterization of Aromatic Polyesters. 國立中央大學碩士論文, 2000.24.Lee, J. W.; Lee, S. W.; Lee, B.; Ree, M. Synthesis and Non-Isothermal Crystallization Characteristics of Poly[(ethylene)-co-(trimethylene terephthalate)]s. Macromol. Chem. Phys. 2001, 202(15), 3072-3080.25.Wu, T. M.; Chang, C. C.; Yu, T. L. Crystallization of Poly(ethylene terephthalate-co-isophthalate). J. Polym. Sci., Part B, Polym. Phys. 2000, 38, 2515-2524.26.Medellín-Rodríguez, F. J.; Phillips, P. J.; Lin, J. S. Melting Behavior of High-Temperature Polymers. Macromolecules 1996, 29, 7491-7501.27.Finelli, L.; Lotti, N.; Righetti, M. C.; Munari, A. Melting Behavior and Crystallization Kinetics of Poly(Butylene terephthalate-co-diethylene terephthalate) and Poly(Butylene terephthalate-co-triethylene terephthalate) Copolyesters. J. Appl. Polym. Sci. 2001, 81, 3545-3551.28. Finelli, L.; Lotti, N.; Munari, A. Crystallization Kinetics and Melting Behavior of Poly(Butylene isophthalate/terephthalate) Random Copolyesters. Eur. Polym. J. 2001, 37, 2039-2046.29.Chuah, H. H. Crystallization Kinetics of Poly(trimethylene terephthalate). Polym. Eng. Sci. 2001, 41(2), 308-313.