Boukis Andreas C, Llevot Audrey, Meier Michael A R
Laboratory of Applied Chemistry, Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany.
Macromol Rapid Commun. 2016 Apr;37(7):643-9. doi: 10.1002/marc.201500717. Epub 2016 Jan 22.
A novel and straightforward one-pot multicomponent polycondensation method was established in this work. The Biginelli reaction is a versatile multicomponent reaction of an aldehyde, a β-ketoester (acetoacetate) and urea, which can all be obtained from renewable resources, yielding diversely substituted 3,4-dihydropyrimidin-2(1H)-ones (DHMPs). In this study, renewable diacetoacetate monomers with different spacer chain lengths (C3, C6, C10, C20) were prepared via simple transesterification of renewable diols and commercial acetoacetates. The diacetoacetate monomers were then reacted with renewable dialdehydes, i.e., terephthalaldehyde and divanillin in a Biginelli type step-growth polymerization. The obtained DHMP polymers (polyDHMPs) displayed high molar masses, high glass transition temperatures (Tg) up to 203 °C and good thermal stability (Td5%) of 280 °C. The Tg of the polyDHMPs could be tuned by variation of the structure of the dialdehyde or the diacetoacetate component.
本工作建立了一种新颖且简便的一锅多组分缩聚方法。Biginelli反应是醛、β-酮酯（乙酰乙酸酯）和尿素的一种通用多组分反应，这些原料均可从可再生资源中获得，反应生成多种取代的3,4-二氢嘧啶-2(1H)-酮（DHMPs）。在本研究中，通过可再生二醇与市售乙酰乙酸酯的简单酯交换反应制备了具有不同间隔链长度（C3、C6、C10、C20）的可再生二乙酰乙酸酯单体。然后，二乙酰乙酸酯单体在Biginelli型逐步增长聚合反应中与可再生二醛，即对苯二甲醛和香草醛二聚体反应。所得的DHMP聚合物（聚DHMPs）具有高摩尔质量、高达203℃的高玻璃化转变温度（Tg）以及280℃的良好热稳定性（Td5%）。聚DHMPs的Tg可通过改变二醛或二乙酰乙酸酯组分的结构来调节。
