本文選題：聚對(duì)苯二甲酸乙二醇酯 + 降解　； 參考：《湖北工業(yè)大學(xué)》2017年碩士論文

【摘要】：聚對(duì)苯二甲酸乙二醇酯(PET)具有優(yōu)異的力學(xué)性能、耐摩擦性能、熱穩(wěn)定性能以及尺寸穩(wěn)定性能等,在傳統(tǒng)的紡織纖維、薄膜以及聚酯瓶等方面有著廣泛的應(yīng)用。但由于PET使用范圍廣,生產(chǎn)以及消費(fèi)中產(chǎn)生的廢棄PET也逐年增加,而PET本身熱穩(wěn)定性良好,自然狀態(tài)下完全降解需要數(shù)十年,故而造成了極為嚴(yán)重的環(huán)境污染問(wèn)題以及資源浪費(fèi)問(wèn)題。PET分子結(jié)構(gòu)與市場(chǎng)上的苯乙烯-丙烯酸丁酯樹(shù)脂(簡(jiǎn)稱碳粉樹(shù)脂)有許多的共同之處。本文以廢棄的PET瓶片為原料,根據(jù)苯丙樹(shù)脂的相關(guān)性能要求,對(duì)其進(jìn)行改性研究。文中先使用醋酸鋅-丙三醇對(duì)PET進(jìn)行降解以降低其分子量,再分別采用聚對(duì)苯二甲酸丁二醇酯與之進(jìn)行酯交換反應(yīng)以破壞其分子鏈規(guī)整性,使用PMMA與之進(jìn)行酯交換反應(yīng)以在其分子鏈上進(jìn)行接枝,最后通過(guò)烏氏粘度計(jì)、旋轉(zhuǎn)流變儀、差示掃描量熱儀、X射線衍射儀以及熱失重分析儀等儀器對(duì)其分子量、酯交換反應(yīng)情況、結(jié)晶性能以及熱穩(wěn)定性能進(jìn)行了表征。實(shí)驗(yàn)表明:(1)丙三醇的加入使PET分子鏈上出現(xiàn)三元環(huán)醚結(jié)構(gòu),當(dāng)丙三醇含量為2%時(shí),PET瓶片測(cè)得的的分子量下降到5022,其熔體粘度有所下降,偏光顯微鏡下的結(jié)晶亮點(diǎn)變得細(xì)小而稀疏,XRD測(cè)得的晶粒尺寸顯著下降,結(jié)晶速率降低,DSC下測(cè)得的結(jié)晶度下降到21.48%,熱分解溫度從406.6 ℃下降到393.5 ℃。(2)通過(guò)反應(yīng)性流變測(cè)試可以明顯看出,PBT與PET熔融共混后,樣品的熔體粘度先增加,反應(yīng)15min后逐漸穩(wěn)定。當(dāng)PBT含量為10%時(shí),樣品的熔體粘度最高,結(jié)晶速率明顯下降,DSC測(cè)得的結(jié)晶度下降到12.42%,偏光顯微鏡下的圖片亮點(diǎn)極為稀少,XRD測(cè)得的晶粒尺寸變化不明顯,熱分解溫度下降到390.1 ℃。(3)使用旋轉(zhuǎn)流變儀能夠明顯的觀察到PMMA與PET酯交換反應(yīng)后,樣品的熔體粘度逐漸增大,可見(jiàn)PMMA通過(guò)酯交換反應(yīng)接枝到PET中去。當(dāng)PMMA含量為10%時(shí),樣品在偏光顯微鏡下的結(jié)晶形貌已經(jīng)極為稀疏,晶粒尺寸變化不明顯,結(jié)晶速率顯著下降,測(cè)得的結(jié)晶度為14.18%,熱分解溫度下降到385.34 ℃。
[Abstract]:Poly (ethylene terephthalate) (PET) has been widely used in traditional textile fibers, films and polyester bottles for its excellent mechanical properties, friction resistance, thermal stability and dimensional stability. However, due to the wide use of PET, the waste PET produced in production and consumption has increased year by year, and the thermal stability of PET itself is good, and it takes decades to completely degrade PET in natural state. The molecular structure of PET has much in common with the styrene-butyl acrylate resin in the market. In this paper, the waste PET bottle was used as raw material, and the modification of the resin was studied according to the properties of styrene-acrylic resin. In this paper, PET was degraded by zinc acetate and glycerol in order to reduce its molecular weight, and then polybutylene terephthalate was used for transesterification to destroy its molecular chain regularity. PMMA was used for transesterification to graft onto its molecular chain, and its molecular weight was finally obtained by means of the Wurtzian viscometer, the rotary rheometer, the differential scanning calorimeter (DSC), the X-ray diffractometer and the thermogravimetric analyzer. The transesterification, crystallization and thermal stability were characterized. The experimental results show that: (1) the structure of ternary cycloether appears in PET molecular chain with the addition of glycerol, and the molecular weight of PET bottle decreases to 5022 when the content of glycerin is 2, and the melt viscosity decreases. The crystalline bright spots under the polarizing microscope become small and the grain size measured by the sparse X-ray diffraction (XRD) decreases significantly. The crystallization rate decreased to 21.48% and the thermal decomposition temperature decreased from 406.6 鈩，

本文編號(hào)：2108690