臺灣博碩士論文加值系統

對於EVA(ethylene-vinyl acetate)在高壓反應器(Autoclave reactor)的共聚合反應，本研究建構數學模式來模擬高壓反應器中各個成份濃度的分佈與反應放熱的情形，進而預測出產物的結構性質與物理性質。模式中將EVA的自由基共聚合反應，利用擬反應動力常數(pseudo kinetic rate constant)簡化反應機構成均聚合反應(homopolymerization)的形式，在反應機構中也同時描述了長鏈分枝的情形，並藉由moment的技巧來估計聚合物的平均分子量。高壓反應器則由於其實際非理想的混和，模式中將反應器分成七個互相串連的反應區，除了起始劑進料與單體進料，各個反應區彼此間亦有回流的存在。而模擬結果與工廠模式預測結果或真實工廠數據相互比較之下，都有相當接近的預測能力。
此外，為了使模式能預測出與實際工廠各個品別相符的產品性質，如產率、熔融指數與聚合物中共單體的分率，依據七種不同品別的EVA，來尋找最適化的動力參數。其中，先藉由定量與定性上的分析找出對產品性質影響最為重要的反應，然後使用三個階段式的尋找策略來做動力參數的最適化。根據熔融指數的不同，最終找到兩組最適化的動力參數，一組適用較低熔融指數的三個品別，另一組適用較高熔融指數的四個品別。

For EVA free radical copolymerization, a mathematical model is developed to simulate composition concentration and reaction heat profile in the high-pressure autoclave reactor. Furthermore the model predicts structural and physical properties of production in the reactor outlet. In the model, EVA kinetic model is simplified to homopolymerization by using pseudo kinetic rate constant method, moreover, the reaction mechanism include the long chain branching frequencies. The technique of moments is then used to find the average molecular weight of polymer. Due to nonideal mixing, the reactor is divided into seven reaction zones in sequence. In addition to initiator and monomer feeds, each zone has mutual back-mixing flow. It is shown that the predicting properties of the proposed model agree well with plant model results and actual manufacturing data.
In order to predict the properties of production such as Production Rate, Melting Index, Comonomer Weight Percent for seven different grades, we try to obtain the optimal kinetic parameters set for the EVA model. First, the most important reactions that affect the properties of production are determined by quantitative and qualitative analysis, then a three-stage approach is deduced to obtain the optimal kinetic parameters in the model. From different Melting Indexes, two sets of optimal kinetic parameters are found. One applies to three grades of lower Melting Indexes; another applies to four grades of higher Melting Indexes.

中文摘要 Ⅰ
英文摘要 Ⅱ
誌謝 Ⅲ
目錄 Ⅳ
表目錄 Ⅵ
圖目錄 Ⅶ
第一章、緒論 1
1.1引言 1
1.2文獻回顧 2
1.3研究動機與目的 5
1.4組織章節 6
第二章、聚合反應原理 7
2.1聚合物結構 9
2.2聚合物類別 11
2.3聚合反應機構 12
2.3.1聚合反應機構的形式 12
2.3.2自由基鏈鎖聚合反應的類型 13
2.3.3自由基鏈鎖聚合反應的典型反應機構 15
2.3.4自由基聚合反應速率表示式 16
2.4鏈轉移反應 20
2.5共聚合反應 23
2.5.1共聚合物的類型 23
2.5.2單體活性比 23
2.6結語 26
第三章、建立模式 27
3.1高壓反應器模式 28
3.2動力學模式 31
3.2.1共聚合反應機構 31
3.2.2擬反應動力常數 33
3.2.3反應速率表示式 37
3.2.4反應速率常數 39
3.3熱力學模式 40
3.3.1壓縮因子 40
3.3.2比熱 42
3.3.3混合物密度 43
3.4聚合物之分子量 45
3.4.1 Moment 平衡式 45
3.4.2聚合物結構性質與物理性質 48
3.5模擬結果 50
3.6結語 59
第四章、動力參數最適化 60
4.1動力參數最適化策略 60
4.2動力參數最適化結果 70
4.3結語 78
第五章、結論 79
符號說明 81
參考文獻 84
附錄 87
作者簡介 93

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