本文選題：高分子 + 高速外場(chǎng)��； 參考：《中國(guó)科學(xué)技術(shù)大學(xué)》2017年碩士論文

【摘要】：流動(dòng)場(chǎng)誘導(dǎo)高分子是一種工業(yè)加工和物理科學(xué)中重要的研究課題。由于高分子鏈獨(dú)特的長(zhǎng)鏈結(jié)構(gòu),具有較長(zhǎng)的鏈松弛時(shí)間,可以通過(guò)高速宏觀外場(chǎng)對(duì)微觀結(jié)構(gòu)進(jìn)行調(diào)控。在很多加工過(guò)程和實(shí)際使用過(guò)程中,高分子往往處于高速外場(chǎng)當(dāng)中,屬于熱力學(xué)非平衡態(tài)。在這種狀態(tài)下,由于鏈變形與松弛的相互競(jìng)爭(zhēng),不同結(jié)構(gòu)在相變過(guò)程中熱力學(xué)穩(wěn)定性與動(dòng)力學(xué)路徑的競(jìng)爭(zhēng)就更加復(fù)雜。本文主要關(guān)注高速外場(chǎng)下誘導(dǎo)高分子結(jié)晶過(guò)程中的結(jié)晶形態(tài)、晶型和結(jié)晶動(dòng)力學(xué),研究結(jié)構(gòu)的形成機(jī)理和動(dòng)力學(xué)競(jìng)爭(zhēng)關(guān)系。設(shè)計(jì)了與原位X射線高時(shí)間分辨散射聯(lián)用的外場(chǎng)施加設(shè)備,并利用這些設(shè)備對(duì)等規(guī)聚丙烯(iPP)及其他不同樣晶體系在不同實(shí)驗(yàn)條件下的結(jié)晶過(guò)程進(jìn)行了原位檢測(cè)。本文的主要結(jié)果如下:1)針對(duì)不同的外場(chǎng)條件和原位時(shí)間分辨X射線散射的檢測(cè)需求,設(shè)計(jì)了多種原位檢測(cè)實(shí)驗(yàn)設(shè)備,包括:多段加速超高速拉伸流變儀、原位拉伸與可控淬火設(shè)備和高速蠕變拉伸流變儀并與寬角/小角X射線散射(SAXS/WAXS)原位檢測(cè)技術(shù)進(jìn)行了原位測(cè)試;設(shè)計(jì)了一套新型的基于量子級(jí)聯(lián)激光器(QCL)的高速構(gòu)象檢測(cè)系統(tǒng)。2)研究等規(guī)聚丙烯在不同溫度和應(yīng)變速率下的拉伸誘導(dǎo)結(jié)晶結(jié)果及其演化規(guī)律。實(shí)驗(yàn)發(fā)現(xiàn)在足夠強(qiáng)的流場(chǎng)下,即使熔點(diǎn)之上,α晶和β晶也可以同時(shí)生成;高溫和高應(yīng)變速率下,β晶相對(duì)更加穩(wěn)定。根據(jù)實(shí)驗(yàn)結(jié)果提出iPP的流動(dòng)場(chǎng)誘導(dǎo)結(jié)晶非平衡相圖,研究非平衡條件下的高分子結(jié)晶行為。3)設(shè)計(jì)并構(gòu)建了γ射線輻照形成的交聯(lián)iPP體系,研究這種交聯(lián)網(wǎng)絡(luò)-短鏈體系在拉伸條件下由于動(dòng)力學(xué)不對(duì)稱性而產(chǎn)生的獨(dú)特的結(jié)晶動(dòng)力學(xué)及晶體形態(tài)的變化。實(shí)驗(yàn)發(fā)現(xiàn),在較大應(yīng)變拉伸下,交聯(lián)iPP體系中的短鏈會(huì)被擠出,并發(fā)生松弛和解纏結(jié),減慢結(jié)晶動(dòng)力學(xué)。而交聯(lián)網(wǎng)絡(luò)不會(huì)發(fā)生松弛,晶體的取向度反而會(huì)連續(xù)增加。由體系松弛時(shí)間尺度的不對(duì)稱造成反常鏈響應(yīng)行為能夠產(chǎn)生獨(dú)特的長(zhǎng)程有序結(jié)構(gòu)。本文的主要?jiǎng)?chuàng)新點(diǎn)如下:1)針對(duì)不同的檢測(cè)條件和檢測(cè)需求,設(shè)計(jì)了不同的高速外場(chǎng)原位檢測(cè)設(shè)備,并對(duì)不同的樣晶體系進(jìn)行了原位觀測(cè)。2)提出了 iPP在溫度-應(yīng)變速率空間的流動(dòng)場(chǎng)誘導(dǎo)結(jié)晶非平衡相圖,研究了iPP在寬溫度和應(yīng)變速率范圍下的動(dòng)力學(xué)相變行為。3)利用交聯(lián)iPP體系作為多分散性高分子的一個(gè)極端體系,探討動(dòng)力學(xué)不對(duì)稱在流動(dòng)場(chǎng)誘導(dǎo)結(jié)晶中對(duì)于相變動(dòng)力學(xué)和結(jié)構(gòu)形態(tài)的影響。
[Abstract]:The flow field induced polymer is an important research topic in industrial processing and physical science. Due to the long chain relaxation time of the unique long chain structure of the polymer chain, the microstructure can be controlled by the high speed macro field. In the process of processing and actual use, the polymer is often in the high speed field. In this state, in this state, the competition between the thermodynamic stability and the dynamic path of the different structures is more complex in the process of phase transition due to the competition between the chain deformation and relaxation. This paper mainly focuses on the crystallization, crystal and crystallization kinetics of the high polymer crystallization process. The formation mechanism and the dynamic competitive relationship are designed. The external field application equipment with high time resolved scattering of X ray in situ is designed, and the crystallization process of iPP and other different crystal systems under the different experimental conditions is detected in situ. The main results of this paper are as follows: 1) for different external fields A variety of in-situ testing equipment, including multi section accelerated ultra high speed stretching rheometer, in situ tensile and controllable quenching equipment and high speed creep tensile rheometer, and in situ testing with wide angle / small angle X ray scattering (SAXS/WAXS) in situ testing, are designed and a set of in situ test is designed. A new type of high speed conformation detection system based on quantum cascade laser (QCL).2) is used to study the tensile induced crystallization of isotactic polypropylene at different temperatures and strain rates. The experimental results show that the alpha and beta crystals can be generated at the same time in the strong flow field even on the melting point; at high temperature and high strain rate, beta crystal phase is at high temperature and high strain rate. It is more stable. According to the experimental results, the non equilibrium phase diagram of the induced crystallization of iPP in the flow field is proposed and the crystallization behavior of polymer.3 under the non equilibrium condition is studied. The cross-linked iPP system formed by gamma ray irradiation is designed and the unique junction produced by the dynamic asymmetry of the crosslinked network short chain system under the tensile condition is studied. It is found that the short chain in the crosslinked iPP system will be extruded under the large strain tension, and the relaxation conciliation and entanglement will occur and the crystallization kinetics are slowed down. The crosslinking network will not relax and the degree of crystal orientation will increase continuously. The asymmetric chain response is caused by the asymmetry of the relaxation time scale of the body system. The main innovations of this paper are as follows: 1) according to the different detection conditions and detection requirements, different high speed field in-situ detection devices are designed, and the in-situ observation.2 of different crystal systems is carried out. The non equilibrium phase induced by iPP in the flow field of temperature stress rate space is proposed. The dynamic phase transition behavior (.3) of iPP at wide temperature and strain rate was studied. The cross linked iPP system was used as an extreme system of polydispersity polymer, and the effect of dynamic asymmetry on the phase transition kinetics and structure morphology in the induced crystallization of the flow field was investigated.
【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O632.12

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 Dong Liu;Kunpeng Cui;Ningdong Huang;Zhen Wang;Liangbin Li;;The thermodynamic properties of flow-induced precursor of polyethylene[J];Science China(Chemistry);2015年10期

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本文編號(hào)：2097545