本文選題：聚己內(nèi)酯 + 酶�。� 參考：《大連海事大學(xué)》2016年碩士論文

【摘要】：作為一種重要的生物可降解型的高分子材料,聚己內(nèi)酯在生物、化工、醫(yī)用材料領(lǐng)域得到了廣泛的應(yīng)用。傳統(tǒng)的化學(xué)方法合成的產(chǎn)物通常會因?yàn)橹亟饘俚臍埩舳憩F(xiàn)出毒性,限制了聚己內(nèi)酯的使用。本文從生物催化的角度出發(fā),探究了利用生物酶進(jìn)行聚己內(nèi)酯的催化合成的合成體系,同時對生物催化合成的聚己內(nèi)酯的產(chǎn)物的降解性能進(jìn)行了初步的探討。本論文利用幾種能夠催化聚酯聚合的生物酶進(jìn)行了己內(nèi)酯的開環(huán)聚合,通過實(shí)驗(yàn)結(jié)果的對比篩選,最終選定了南極假絲酵母脂肪酶B為己內(nèi)酯開環(huán)聚合的催化劑,并利用其固定化形式Novozyme 435進(jìn)行了生物酶催化己內(nèi)酯開環(huán)聚合的最適反應(yīng)體系的探究。利用紅外線光譜分析儀(FTIR)、X射線衍射(XRD)、核磁氫譜分析(1HNMR)、示差掃描量熱儀(DSC)、綜合熱分析儀(TGA)、凝膠滲透色譜(GPC)等手段,結(jié)合產(chǎn)物的轉(zhuǎn)化率、分子量等變化,確定了酶催化聚合的催化劑的使用量、聚合反應(yīng)的溫度、反應(yīng)時間、反應(yīng)溶劑的選擇以及探究了酶重復(fù)利用的催化能力。研究結(jié)果表明,催化劑的用量較大程度上影響產(chǎn)物的轉(zhuǎn)化率,以10ml己內(nèi)酯為反應(yīng)原料的前提下,催化劑為0.50g的使用量可以得到相對較高轉(zhuǎn)化率的產(chǎn)物；在生物酶的活性溫度范圍內(nèi)確定了反應(yīng)的最適溫度為45℃；在上述確定的反應(yīng)體系下,對反應(yīng)時間進(jìn)行了考察,結(jié)果表明,隨著反應(yīng)時間的增加,產(chǎn)物的分子量逐步上升,確定了24h為最適反應(yīng)時間；還對反應(yīng)的溶劑進(jìn)行了探討,發(fā)現(xiàn)疏水性溶劑更有利于該聚合反應(yīng)進(jìn)行的現(xiàn)象,最后對酶重復(fù)催化的性能進(jìn)行了探討,酶的催化性能呈現(xiàn)逐步降低的趨勢,但隨著催化次數(shù)的增多,其催化能力下降趨勢逐漸趨向于平穩(wěn),表明了酶重復(fù)再利用的可行性。本文也對酶催化合成的聚己內(nèi)酯降解性能的初步探討,樣品的失重率以及單位面積失重隨著降解時間的增加而逐漸增加,無溶劑體系下Novozyme 435催化聚合的產(chǎn)物的降解速率快于甲苯溶劑下的產(chǎn)物�？傮w上,酶催化己內(nèi)酯聚合的產(chǎn)物的降解性能由于傳統(tǒng)的化學(xué)方法催化合成的聚己內(nèi)酯
[Abstract]:As an important biodegradable polymer, polycaprolactone has been widely used in biological, chemical and medical materials. The products synthesized by traditional chemical methods are usually toxic because of heavy metal residues, limiting the use of polycaprolactone. From the point of view of biocatalysis, the synthesis system of polycaprolactone with biological enzyme was studied, and the degradation performance of polycaprolactone synthesized by biocatalysis was also discussed. In this paper, the ring-opening polymerization of caprolactone was carried out by using several biological enzymes that can catalyze the polymerization of polyester. Finally, the lipase B of Candida Antarctica was selected as the catalyst for the ring-opening polymerization of caprolactone. The optimum reaction system for the ring-opening polymerization of caprolactone catalyzed by biological enzyme was studied by using its immobilized form Novozyme 435. Infrared spectrometer (FTIR) X-ray diffraction (XRD), nuclear magnetic hydrogen spectroscopy (1HNMR), differential scanning calorimetry (DSC), comprehensive thermal analyzer (TGA), gel permeation chromatography (GPC) were used to combine the conversion and molecular weight of the products. The amount of catalyst used for enzymatic polymerization, the temperature of polymerization, the reaction time, the selection of reaction solvent and the catalytic ability of enzyme reuse were determined. The results showed that the amount of catalyst affected the conversion of the product to a large extent. Under the premise of using 10ml caprolactone as raw material, the product with higher conversion could be obtained when the amount of catalyst was 0.50g. The optimum reaction temperature was 45 鈩，

本文編號：2102564