簡易檢索 / 詳目顯示

回結果列表
研究生： 徐翊芸
Yi-Yun Hsu
論文名稱： 退火加工對於熱塑性聚氨酯發泡之影響
Effect of annealing on thermoplastic polyurethane foam
指導教授： 蘇舜恭
Shuenn-Kung Su
口試委員: 蘇舜恭
Shuenn-Kung Su
葉樹開
Shu-Kai Yeh
鄭智嘉
Chih-Chia Cheng
學位類別： 碩士
Master
系所名稱： 工程學院 - 材料科學與工程系
Department of Materials Science and Engineering
論文出版年： 2020
畢業學年度： 108
語文別： 中文
論文頁數： 131
中文關鍵詞： 熱塑性聚氨酯 、批次發泡 、二氧化碳 、退火 、硬度
外文關鍵詞： Thermoplastic polyurethane, Batch foam, carbon dioxide, annealing, hardness
相關次數： 點閱：380  下載：3 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報
  •  上一筆

    • 目前PU的發泡產品充斥於市面上，但PU屬於熱固型材料，無法於回收後透過再加工而重複利用，若能以熱塑型的TPU來取代傳統PU泡材，將能更符合循環經濟。TPU屬於嵌段型的共聚物，硬段與軟段間會有微相分離的情形，隨著軟硬鏈段的比例不同和微相分離程度的差異，機械性質、熔點、結晶度都會有差異，而微相分離的程度，取決於TPU中分子鏈段的移動能力，其中影響到分子鏈移動能力最直接的因素就是環境溫度。因此本研究將先以退火加工，改變TPU內的微相分離情形，並於相同的發泡條件下進行發泡，分析退火加工對於TPU發泡的影響，本研究大約分成三部分進行。
    第一部分探討退火加工對於TPU材料的變化，對退火加工後的TPU進行拉伸試驗，分析退火溫度對機械性質的影響，發現經過退火加工後，TPU的楊氏模數會下降，斷裂應力與斷裂伸長率則都會上升。並且以DSC分析退火後TPU內硬段的排序程度以及硬段排序的含量，退火溫度越高，硬段會排列得更有序，但是長序硬段的含量會下降。
    第二部分比較TPU經過不同退火溫度與時間的加工後，再進行一步法批次發泡的差異。含浸過程亦是退火加工的一種，退火的溫度要高於含浸溫度，才會造成硬段排序程度與含量的差異。退火溫度若高於含浸溫度，TPU內長序硬段的含量較低，可以得到膨脹倍率較大的泡材。
    第三部分則分析85、90、95A三種不同硬度的TPU，分別於退火加工後對發泡的影響。95A的TPU在DSC分析中具有高於200 °C的結晶峰，以160 °C的退火溫度難以熔掉這些緻密的結晶，故退火前後的TPU樣品會得到一樣的發泡結果。以150、160 °C退火硬度為85A、90A的TPU，發泡後膨脹倍率都會增加。

    At present, PU foam products are prevalent in the market, but it is a thermosetting material and cannot be reused through reprocessing after recycling. If the traditional PU foam can be replaced with a thermoplastic TPU, it will conform the concept of the circular economy. TPU is a block copolymer, and there will be a micro-phase separation between the hard segment and the soft segment. As the degree of micro-phase separation and the soft and hard segment ratio change, the mechanical properties, melting point, and crystallinity would change accordingly.The degree of micro-phase separation depends on the mobility of chain segments in TPU, the most critical factor that affects the mobility of molecular chains is the temperature. Therefore, this study will first use annealing to change the micro-phase separation in the TPU and foam under the same foaming conditions (foaming after saturate in 1100 psi carbon dioxide at 140 °C for 1 hour), to analyze the effect of annealing on TPU foaming, this study is divided into three parts.
    Part I discusses the changes of annealing condition on TPU materials. The annealed TPU was characterized by the tensile test to analyze the effect of annealing temperature on mechanical properties. It was found that annealing would decrease the Young's modulus but the elongation at break and tensile stress increased.The DSC analysis results showed that annealing would result in more ordered structure in TPU; however, the content of the long-range order decreases wit hteh annealing temperature.
    Part II compared the effect of annealing temperature and time to the foaming process. Since a saturation temperature of 140 C was applied, the saturation process is also considered as an annealing process. Our results showed that the annealing temperature has to be higher than the saturation temperature to cause a significant difference. Once the annealing temperature is higher than the saturation temperature, the amount of long-range order hard segments decreased and thus increased the foam expansion ratio.
    Part III analyzed the effects of hardness and annealing on the foaming. The 95A TPU has a crystal melting peak higher than 200 °C. It is difficult to melt these crystals at the annealing temperature below 160 °C. So annealing would not create any difference on expansion ratio and cell structure of the TPU foam. On the other hand, annealing would create a significant difference for 85A and 90A sample. The expansion ratio of both TPU grades increased significantly after annealing.

    摘要 I 誌謝 V 目錄 VI 圖目錄 IX 表目錄 XI 第一章、緒論 1 1.1前言 1 1.2研究動機 2 1.3研究目的 2 第二章、文獻回顧 3 2.1聚氨酯(PU)與熱塑性聚氨酯(TPU)簡介 3 2.1.1熱塑性聚氨酯的原料 9 2.1.2熱塑性聚氨酯的微相分離 13 2.2高分子發泡材料 17 2.2.1發泡劑 19 2.2.2發泡機制 22 2.2.3批次發泡 25 2.2.4發泡珠粒 (bead foam) 26 2.3退火熱處理 28 第三章、實驗方法 31 3.1實驗藥品 31 3.2實驗儀器 34 3.3實驗步驟 36 3.3.1實驗流程圖 36 3.3.2混煉不同硬度之TPU 37 3.3.3以射出成形製備啞鈴形TPU試片 37 3.3.4退火加工 38 3.3.5批次發泡 39 3.4 材料物性分析 42 3.4.1熱重分析儀 (TGA) 42 3.4.3熱示差掃描量熱儀 (DSC) 43 3.4.4拉伸試驗 43 3.4.5掃描式電子顯微鏡(SEM) 45 3.4.6泡材密度(foam density)量測 46 3.4.7泡材膨脹倍率(expansion ratio)及收縮率計算 46 3.4.8泡孔尺寸(cell size)計算 48 3.4.9泡孔密度(cell density)計算 48 第四章、結果與討論 49 4.1 TPU材料分析 49 4.1.1熱重損失分析 49 4.1.2分子量分析 50 4.1.3退火85PR-TPU 60分鐘後拉伸試驗結果 51 4.1.4退火85PR-TPU 60分鐘後DSC分析 53 4.2 退火溫度對於批次發泡之影響 58 4.2.1以不同溫度退火85PR-TPU發泡後膨脹倍率與收縮情形 58 4.2.2以不同溫度退火85PR-TPU發泡後泡孔尺寸與密度 60 4.2.3以不同溫度退火85PR-TPU發泡後DSC分析 62 4.3 以不同溫度退火85PR-TPU含浸後DSC分析 64 4.4退火時間對於批次發泡之影響 67 4.4.1退火85PR-TPU不同時間後的材料分析 67 4.4.2退火85PR-TPU不同時間發泡後泡材分析 70 4.5退火對不同硬度TPU的影響 75 4.5.1 以160 °C退火不同硬度TPU的材料分析 75 4.5.2以160 °C退火TPU 60分鐘含浸緩洩後樣品之DSC分析 78 4.5.3退火不同硬度TPU 60分鐘發泡後泡材分析 79 4.6實驗總表 84 4.6.1退火後材料分析 84 4.6.2含浸後分析 86 4.6.3 發泡後分析 87 第五章、結論 89 參考文獻 91 附錄 99 附錄A流變測試 99 附錄B 退火90A及95A TPU不同時間比較 100 B.1退火後DSC分析 100 B.2退火並發泡後的膨脹倍率與泡孔結構分析 103 附錄C 95A不同混煉溫度比較 106 C.1混煉後DSC分析 106 C.2發泡後膨脹倍率與泡孔結構 107 附錄D 樣品外觀照片 110 附錄E 泡體內裂縫照片 113 附錄F 以TMA進行軟化點分析 115 附錄G 以DMA進行動態機械性質分析 116

    1. Complete guide on thermoplastic polyurethanes(TPU). https://omnexus.specialchem.com/selection-guide/thermoplastic-polyurethanes-tpu. accessed date: 2020 April 16.
    2. Thermoplastic polyurethane market by raw material, type, end-use industry, region-global forecast to 2024. https://www.marketsandmarkets.com/Market-Reports/thermoplastic-polyurethanes-market-1091.html. accessed date: 2020 April 16.
    3. Song J.J., Chang H.H., and Naguib H.E. Design and characterization of biocompatible shape memory polymer (SMP) blend foams with a dynamic porous structure. Polymer, 2015; 56(15): 82-92.
    4. Prasad A., Fotou G., and Li S. The effect of polymer hardness, pore size, and porosity on the performance of thermoplastic polyurethane-based chemical mechanical polishing pads. Journal of Materials Research, 2013; 28(17): 2380-2393.
    5. Huang W., Dai K., Zhai Y., Liu H., Zhan P., Gao J., Zheng G., Liu C., and Shen C. Flexible and lightweight pressure sensor based on carbon nanotube/thermoplastic polyurethane-aligned conductive foam with superior compressibility and stability. ACS Applied Materials and Interfaces, 2017; 9(48): 42266-42277.
    6. Polyurethanes now material of choice for sports shoes. https://www.icis.com/explore/resources/news/2014/09/19/9822302/acc-polyurethanes-now-material-of-choice-for-sports-shoes/. accessed date: 2020 April 16.
    7. Basf. Infinergy® The first expanded TPU-Small beads, high performance. https://www.basf.com/be/en/media/Magazine/quality-of-life/energy-every-step-of-the-way.html. accessed date: 2020 April 16.
    8. Adidas launched its fully recyclable running shoes. https://greenchemicalsblog.com/2019/04/18/adidas-launched-its-fully-recyclable-running-shoe/. accessed date: 2020 May 17.
    9. 徐廷豪, 以超臨界二氧化碳技術探討不同硬度熱塑性聚氨酯之發泡行為,碩士論文,國立臺灣科技大學,材料科學與工程研究所.2019.
    10. 黃思瑤, 不同軟段多元醇組成熱塑性聚氨酯之泡材熱性質探討.碩士論文,國立臺灣科技大學,材料科學與工程研究所.2018.
    11. Kong Z., Tian Q., Zhang R., Yin J., Shi L., Wu B., Hu H., Yao C., Wang K., and Zhu J. Reexamination of the microphase separation in MDI and PTMG based polyurethane: Fast and continuous association/dissociation processes of hydrogen bonding. Polymer, 2019; 185(17): 121943 - 121953.
    12. Wang L. Polyurethane foam-from furniture cushions to insulation, versatile polymer has found a world of applications. Chemical and Engineering News, 2006; 84(2): 48.
    13. The essential chemical industry-online: polyurethanes. https://www.essentialchemicalindustry.org/polymers/polyurethane.html. accessed date: 2020 May 1.
    14. Bernardini J., Licursi D., Anguillesi I., Cinelli P., Coltelli M.B., Antonetti C., Galletti A., and Lazzeri A. Exploitation of Arundo donax L. Hydrolysis Residue for the green synthesis of flexible polyurethane foams. BioResources, 2017; 12(2): 3630-3655.
    15. How polyurethane is made. http://www.madehow.com/Volume-6/Polyurethane.html. accessed date: 2020 May 13.
    16. Polyurethane foam market by type (flexible, rigid, spray foam), end user (bedding and furniture, building and construction, electronics, automotive, footwear, packaging), and region (Asia Pacific, Europe, North America) - global forecast to 2023. https://www.marketsandmarkets.com/Market-Reports/polyurethane-foams-market-1251.html. accessed date: 2020 April 16.
    17. American chemistry council. Guidance on best practices for the installation of spray polyurethane foam. 2012: 1 - 50.
    18. He Y., Xie D., and Zhang X. The structure, microphase-separated morphology, and property of polyurethanes and polyureas. Journal of Materials Science, 2014; 49: 7339 - 7352.
    19. Matsushita Y. Microphase separation (of block copolymers). Ebook package, chemistry and material science reference module physical and materials science. Springer Berlin Heidelberg, 2014: 1-6.
    20. Carraher C.E. 2003. Seymour/Carraher's polymer chemistry: 6th edition. Chapter 10: 381 - 387. Boca Raton, FL: CRC Press.
    21. Prisacariu C. 2011. Polyurethane elastomers. Chapter 1: 5. New York: Springer.
    22. 塑料技術-TPU 熱塑彈性體. http://www.ibuyplastic.com/. accessed date: 2020 May 4.
    23. Flory P.J. 1953. Principles of polymer chemistry. Chapter 3: 70 -71. Ithaca: Cornell University Press.
    24. Jiang J., Fu Y., Zhang Q., Zhan X., and Chen F. Novel amphiphilic poly(dimethylsiloxane) based polyurethane networks tethered with carboxybetaine and their combined antibacterial and anti-adhesive property. Applied Surface Science, 2017; 412(1): 1-9.
    25. 劉厚鈞.2001.聚氨酯彈性體手册,第四章聚氨酯彈性體性能與結構的關係.北京:化學工業出版社.
    26. Gayman R.J. Segmented copolymers with monodisperse crystallizable hard segments: Novel semi-crystalline materials. Progress in Polymer Science, 2011; 36(6): 713-748.
    27. Cipriani E., Zanetti M., Brunella V., Costa L., and Bracco P. Thermoplastic polyurethanes with polycarbonate soft phase: Effect of thermal treatment on phase morphology. Polymer Degradation and Stability, 2012; 97(9): 1794-1800.
    28. Garrett J.T., Runt J., Lin J.S. Microphase separation of segmented poly(urethane urea) block copolymers. Macromolecules, 2000; 33(17): 6353-6359.
    29. Seymour R.W., Cooper, S.L. DSC studies of polyurethane block polymers. Journal of Polymer Science Part B: Polymer Letters, 1971; 9: 689-694.
    30. Lamba N.M.K., Woodhouse K.A., Cooper S.L. 1998. Polyurethanes in biomedical applications: 277. Boca Raton, FL: CRC Press.
    31. Briber R.M., and Thomas E.L. Investigation of two crystal forms in MDI/BDO-based polyurethanes. Journal of Macromolecular Science, Part B, 1983; 22(4): 509-528.
    32. Briber R.M., and Thomas E.L. The structure of MDI/BDO-based polyurethanes: Diffraction studies on model compounds and oriented thin films. Journal of Polymer Science: Polymer Physics Edition, 1985; 23(9): 1915-1932.
    33. Pompe G., Pohlers P., potschke P., and Pionteck J. Influence of processing conditions on the multiphase structure of segmented polyurethane. Polymer, 1998; 39(21): 5147-5153.
    34. Hesketh T.R., Van Bogart J.W.C., and Cooper S.L. Differential scanning calorimetry analysis of morphological changes in segmented elastomers. Polymer Engineering and Science, 1980; 20(3): 190-197.
    35. Yang H., Wang X., Song L., Yu B., and Yuan R.K. Aluminum hypophosphite in combination with expandable graphite as a novel flame retardant system for rigid polyurethane foams. Polymers for Advanced Technologies, 2014; 25(9): 1034-1043.
    36. Li Y., Pei X., Shen B., Zhai W., Zhanga L., Zheng W. Polyimide/graphene composite foam sheets with ultrahigh thermostability for electromagnetic interference shielding. RSC Advances, 2015; 5(31): 24342-24351.
    37. Oktay B., Kayaman-Apohan N., Erdem‐Kuruca S., Süleymanoğlu M. Fabrication of collagen immobilized electrospun poly (vinyl alcohol) scaffolds. Polymers for Advanced Technologies, 2015; 26(8): 978-987.
    38. Sadik T., Pillon C., Carrot C., Ruiz J., Vincent M., and Billon N. Polypropylene structural foams: Measurements of the core, skin, and overall mechanical properties with evaluation of predictive models. Journal of Cellular Plastics, 2017; 53(1): 25-44.
    39. Okolieocha C., Raps D., Subramaniam K., and Altstädt V. Microcellular to nanocellular polymer foams: progress (2004–2015) and future directions – A review. European Polymer Journal, 2015; 73: 500-519.
    40. Lee S.T., Park C.B. 2014. Foam extrusion principles and practice ed. S. edition. Boca Raton, FL: CRC Press.
    41. Atalla Y., Fu J., Atalla N., and Naguib H.E. Study of the effects of processing parameters on the sound absorption of open-cell microcellular polymeric foams. Noise Control Engineering Journal - NOISE CONTR ENG J, 2010; 58: 18-26.
    42. Suh K.W., Park C.B., Maurer M.J., Tusim M.H., Genova R.D, Broos R., and Sophiea D.P. Lightweight cellular plastics. Advanced Materials, 2000; 12(23): 1779-1789.
    43. Shimbo M., Baldwin D.F., and Suh N.P. The viscoelastic behavior of microcellular plastics with varying cell size. Polymer Engineering and Science, 1995; 35(17): 1387-1393.
    44. Shimbo M., Higashitani I., and Miyano Y. Mechanism of strength improvement of foamed plastics having fine cell. Journal of Cellular Plastics, 2007; 43(2): 157-167.
    45. Lee P.C., Wang J., and Park C.B. Extruded open-cell foams using two semicrystalline polymers with different crystallization temperatures. Industrial and Engineering Chemistry Research, 2006; 45(1): 175-181.
    46. Pinto J., Athanassiou A., and Fragouli D. Effect of the porous structure of polymer foams on the remediation of oil spills. Journal of Physics D: Applied Physics, 2016; 49(14): 145601 - 145610.
    47. 何繼敏.2008.聚合物發泡材料及技術,第二章發泡劑種類與性能.北京: 化學工業出版社.
    48. Wong A., Howe L., Mohammad M., Hasan M., Park C.B. The synergy of supercritical CO2 and supercritical N2 in foaming of polystyrene for cell nucleation. The Journal of Supercritical Fluids, 2014; 90: 35-43.
    49. Heck III R.L. A review of commercially used chemical foaming agents for thermoplastic foams. Journal of Vinyl and Additive Technology, 1998; 4(2): 113-116.
    50. Shukla S., and Koelling K.W. Steady flow simulation of a polymer-diluent solution through an abrupt axisymmetric contraction using internally consistent rheological scaling. Journal of Applied Polymer Science, 2007; 106(2): 1053-1074.
    51. Culbertson B.M. 1990. Multiphase Macromolecular Systems: 339 – 361. Berlin: Springer.
    52. Darr J.A., and Poliakoff M. New Directions in inorganic and metal-organic coordination chemistry in supercritical fluids. Chemical Reviews, 1999; 99(2): 495-542.
    53. Goel S.K., and Beckman E.J. Generation of microcellular polymeric foams using supercritical carbon dioxide. I: Effect of pressure and temperature on nucleation. Polymer Engineering and Science, 1994; 34(14): 1137-1147.
    54. Goel S.K., and Beckman E.J. Generation of microcellular polymeric foams using supercritical carbon dioxide. II: Cell growth and skin formation. Polymer Engineering and Science, 1994; 34(14): 1148-1156.
    55. Davarpanah A. Evaluation of gas injection in the horizontal wells and optimizing pil recovery factor by eclipse software. Journal of Chromatography Separation Techniques, 2016; 7(6): 1000344 - 1000348.
    56. Park C.B., Baldwin D.F., and Suh N.P. Effect of the pressure drop rate on cell nucleation in continuous processing of microcellular polymers. Polymer Engineering and Science, 1995; 35(5): 432-440.
    57. Xu Z.M., Jiang X.L., Liu T., Hu G.H., Zhao L., Zhu Z.N., and Yuan W.K. Foaming of polypropylene with supercritical carbon dioxide. The Journal of Supercritical Fluids, 2007; 41(2): 299-310.
    58. Sakrani S., Jie L., and Yussof W. The formation of nanoscale clusters - nanofilms / quantum dots predicted using a capillary model of nucleation. Malaysian Journal of Fundamental and Applied Sciences, 2005; 1(1): 23-33.
    59. Taqieddin A., Allshouse M., and Alshawabkeh A. Editors' choice—critical review—mathematical formulations of electrochemically gas-evolving systems. Journal of The Electrochemical Society, 2018; 165: E694-E711.
    60. Spitael P., Mocosko C.W., McClurg R.B. Block copolymer micelles for nucleation of microcellular thermoplastic foams. Macromolecules, 2004; 37(18): 6874-6882.
    61. Colton J.S. and Suh N.P. The nucleation of microcellular thermoplastic foam with additives: Part I: Theoretical considerations. Polymer Engineering and Science, 1987; 27(7): 485-492.
    62. Colton J.S. and Suh N.P. The nucleation of microcellular thermoplastic foam with additives: Part II: Experimental results and discussion. Polymer Engineering and Science, 1987; 27(7): 493-499.
    63. Arora K.A., Lesser A.J., and McCarthy T.J. Preparation and characterization of microcellular polystyrene foams processed in supercritical carbon dioxide. Macromolecules, 1998; 31(14): 4614-4620.
    64. Leung S.N., Park C.B., Xu D., Li H., and Fenton R.G. Computer simulation of bubble-growth phenomena in foaming. Industrial and Engineering Chemistry Research, 2006; 45(23): 7823-7831.
    65. Sun X., Liu H., Li G., Liao X., and He J. Investigation on the cell nucleation and cell growth in microcellular foaming by means of temperature quenching. Journal of Applied Polymer Science, 2004; 93(1): 163-171.
    66. Gotsis A.D., Zeevenhoven B.L.F., and Tsenoglou C. Effect of long branches on the rheology of polypropylene. Journal of Rheology, 2004; 48(4): 895-914.
    67. Costeux S. CO2-blown nanocellular foams. Journal of Applied Polymer Science, 2014; 131(23): 41293 - 41309.
    68. Guo Y., Hossieny N., Chu R.K.M., Park C.B., and Zhou N. Critical processing parameters for foamed bead manufacturing in a lab-scale autoclave system. Chemical Engineering Journal, 2013; 214: 180-188.
    69. Lee E.K. Novel Manufacturing processes for polymer bead foams. PhD thesis, Department of Mechanical and Industrial Engineering, University of Toronto, 2010.
    70. Yeh S.K., Liu W.H., and Huang Y.M. Carbon dioxide-blown expanded polyamide bead foams with bimodal cell structure. Industrial and Engineering Chemistry Research, 2019; 58(8): 2958-2969.
    71. Hossieny N. Development of expanded thermoplastic polyurethane bead foams and their sintering mechanism. PhD thesis, Department of Mechanical and Industrial Engineering University of Toronto (Canada), 2014.
    72. Raps D., Hossieny N., Park C.B., and Altstädt V. Past and present developments in polymer bead foams and bead foaming technology. Polymer, 2015; 56: 5-19.
    73. Wagner J., Ciesielski M., and Doering M. Halogen free flame retardants for polystyrene foams. journal of fire sciences, 2012: 3-16.
    74. Klodt R.D., and Gougeon B. Particle foam based on expandable polystyrene (EPS). 2003: 163-201.
    75. Kurtz wave foamer. https://www.kurtzersa.com/moulding-machines/products/particle-foam-machines/shape-moulding-machines/produkt-details/kurtz-wave-foamer-1.html. accessed date: 2020 May 2.
    76. Petermann J., Miles M., and Gleiter H. Growth of polymer crystals during annealing. Journal of Macromolecular Science, Part B, 1976; 12(3): 393-404.
    77. Verhoeven J.D. 1975. Fundamentals of physical metallurgy. Chapter 10: 326. Hoboken, NY: John Wiley and Sons.
    78. Leung L.M., and Koberstein J.T. DSC annealing study of microphase separation and multiple endothermic behavior in polyether-based polyurethane block copolymers. Macromolecules, 1986; 19(3): 706-713.
    79. Frick A., and Rochman A. Characterization of TPU-elastomers by thermal analysis (DSC). Polymer Testing, 2004; 23(4): 413-417.
    80. Yanagihara Y., Osaka N., Murayama S., and Saito H. Thermal annealing behavior and structure development of crystalline hard segment domain in a melt-quenched thermoplastic polyurethane. Polymer, 2013; 54(8): 2183-2189.
    81. Kong Z., Tian Q., Zhang R., Yin J., Shi L., Wu B., Hu H., Yao C., Wang K., and Zhu J., Reexamination of the microphase separation in MDI and PTMG based polyurethane: Fast and continuous association/dissociation processes of hydrogen bonding. Polymer, 2019; 185: 121943 - 121953.
    82. 康庭瑋, 高分子硬度對超臨界二氧化碳發泡技術製備熱塑性聚氨酯微奈米孔洞泡材之影響.碩士論文.國立臺北科技大學, 化學工程與生物科技系, 2015.
    83. Hossieny N.J., Barzegari M.R., Nofar M., Mahmood S.H.,and Park C.B. Crystallization of hard segment domains with the presence of butane for microcellular thermoplastic polyurethane foams. Polymer, 2014; 55(2): 651-662.
    84. Bogart V.J.W.C., Bluemke D.A., and Cooper S.L. Annealing-induced morphological changes in segmented elastomers. Polymer, 1981; 22(10): 1428-1438.
    85. Carraher Jr.C.E. 2006. Introduction to polymer chemistry. Chapter 3: 60 – 63. Boca Roton, FL: CRC Press.
    86. Vo C.V., and Paquet A.N. An evaluation of the thermal conductivity of extruded polystyrene foam blown with HFC-134a or HCFC-142b. Journal of Cellular Plastics, 2004; 40(3): 205-228.
    87. Lin Y., Zhong W., Shen L., Xu P., and Du Q. Study on the relationship between crystalline structures and physical properties of polyamide‐6. Journal of Macromolecular Science, Part B, 2005; 44(2): 161-175.
    88. Tomasko D.L., Li H., Liu D., Han X., Wingert M.J., Lee L.J., Koelling K.W. A review of CO2 applications in the processing of polymers. Industrial and Engineering Chemistry Research, 2003; 42(25): 6431-6456.

    QR CODE