本文選題：環(huán)內(nèi)酯 + 乙交酯�。� 參考：《天津科技大學(xué)》2017年碩士論文

【摘要】：環(huán)內(nèi)酯聚合物因?yàn)榫哂辛己玫目缮锝到庑院蜕锵嗳菪?已經(jīng)被越來越多的人們所關(guān)注,但由于生產(chǎn)成本較高,很大程度上制約了它在實(shí)際生活中的應(yīng)用。聚乙交酯和聚丙交酯是應(yīng)用最多的環(huán)內(nèi)酯聚合物,而作為其聚合反應(yīng)單體的乙交酯和丙交酯的成本及產(chǎn)品性能對于環(huán)內(nèi)酯聚合物的普及有著極其重要的作用。本文首先以羥基乙酸為原料,分別用熔融法和共沸溶劑法制備了乙交酯,通過控制變量法,研究了催化劑體系、催化劑用量、升溫速率、解聚劑的分子量、解聚溫度以及高沸點(diǎn)有機(jī)溶劑等反應(yīng)條件對乙交酯產(chǎn)率的影響,然后采用不同的溶劑體系對乙交酯進(jìn)行了純化,在不同的溫度下進(jìn)行重結(jié)晶,制備出α晶型和β晶型的乙交酯,并通過熔點(diǎn)、紅外光譜、核磁共振氫譜、X-射線衍射圖、熱分析圖和偏光顯微圖對產(chǎn)物乙交酯進(jìn)行了表征。實(shí)驗(yàn)研究結(jié)果表明,乙交酯合成的最佳條件如下:在高沸點(diǎn)有機(jī)溶劑聚乙二醇二甲醚(NHD)和四乙二醇二甲醚(TGDE)作為混合溶劑的條件下,解聚反應(yīng)階段升溫速率為15℃/min,解聚溫度為225℃時,乙交酯的粗產(chǎn)率可達(dá)91.61%;乙交酯純化的最佳溶劑體系為乙酸乙酯與丙酮的體積比(3～9):1,總產(chǎn)率可達(dá)79.4%;通過偏光顯微鏡觀察,發(fā)現(xiàn)α晶型為薄片狀而β晶型為顆粒狀,其中β3晶型更易形成二聚體,有利于發(fā)生聚合反應(yīng)。另外,以L-乳酸為原料,采用熔融法和共沸溶劑法制備了 L-丙交酯,通過控制變量法,研究了催化劑體系、催化劑用量、縮聚反應(yīng)時間和解聚溫度等反應(yīng)條件對L-丙交酯產(chǎn)率的影響,并研究了重結(jié)晶次數(shù)對L-丙交酯純度的影響,最后采用酸堿滴定法測定了 L-丙交酯中微量水和乳酸的含量,通過熔點(diǎn)、紅外光譜、核磁共振氫譜、X-射線衍射圖和熱分析圖對產(chǎn)物L(fēng)-丙交酯進(jìn)行了表征。實(shí)驗(yàn)研究結(jié)果表明,制備過程中采用溶劑共沸法,L-丙交酯合成的最佳條件如下:催化劑氧化鋅和辛酸亞錫的摩爾比為7:3,其用量為L-乳酸質(zhì)量的1%,縮聚反應(yīng)時間為4h,解聚溫度為240℃時,L-丙交酯的粗產(chǎn)率可達(dá)89.57%;使用乙酸乙酯作為溶劑,當(dāng)重結(jié)晶3次時,純化L-丙交酯的產(chǎn)率和純度最優(yōu)。最后分別對乙交酯和L-丙交酯的制備過程進(jìn)行了物料衡算,為乙交酯和L-丙交酯的規(guī)模化生產(chǎn)提供了一定的依據(jù)。
[Abstract]:Because of its good biodegradability and biocompatibility, cyclic lactone polymer has been paid more and more attention by people. However, because of its high production cost, its application in real life is restricted to a great extent.Poly (glycolide) and polylactide (poly (lactide)) are the most widely used cyclic lactone polymers. The cost and product performance of glycolide and lactide as monomers play an important role in the popularization of cyclic lactone polymers.In this paper, glycolide was prepared by melt method and azeotropic solvent method using glycolic acid as raw material. The catalyst system, amount of catalyst, heating rate, molecular weight of depolymerization agent were studied by controlling variable method.The effects of depolymerization temperature and high boiling point organic solvent on the yield of glycolide were studied. Then the glycolide was purified by different solvent systems and recrystallized at different temperatures to produce 偽 -crystalline and 尾 -crystalline glycolide.The product was characterized by melting point, infrared spectrum, H-NMR X-ray diffraction, thermal analysis and polarizing microscopy.The experimental results show that the optimum conditions for the synthesis of glycolide are as follows: under the conditions of high boiling point organic solvents polyethylene glycol dimethyl ether (NHDD) and tetraethylene glycol dimethyl ether (TGDED) as mixed solvents,The crude yield of glycolide can reach 91.61 when the heating rate is 15 鈩，

本文編號：1737215