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首页> 外文期刊>Journal of Polymers and the Environment >Kinetic Behavior in Melt State and Solid State Polymerization of Lactide Using Magnesium Stearate as Catalyst
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Kinetic Behavior in Melt State and Solid State Polymerization of Lactide Using Magnesium Stearate as Catalyst

机译：硬脂酸镁为催化剂的丙交酯熔融态和固态聚合的动力学行为

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摘要

Solid state polymerizations (SSP) and the kinetic behavior in melt state of 1-lactide polymerizations employing magnesium stearate as catalyst were investigated. The solid state polymerizations were carried out in two steps where pre-polymers were first prepared in melt polymerizations at 180 ℃ and the subsequent post-polymerizations were performed around the Tc of polylactide (PLA). In order to find the initial SSP conditions, kinetic profiles of melt polymerizations of 1-lactide with magnesium stearate were determined. According to the kinetics data the melt polymerizations were found to be first order with respect to lactide as evident from a linear relationship of logarithmic variations of 1-lactide concentration versus time using catalyst/monomer ratios of 1:500 and 1:5,000. When the catalyst content is increased to 1:100 the relationship loses its linearity due to fast propagation in the early stages of the reaction. From the GPC data it can be noted that the molecular weight of PLA can be increased by 5-17 times under the conditions established for our SSP experiments. A comparison between the two step solid state polymerizations and already reported melt polymerizations using the same catalyst showed that SSP furnished polymers with much lower amount of polymer degradation.
机译：研究了固态聚合（SSP）和以硬脂酸镁为催化剂的1-丙交酯聚合在熔融态下的动力学行为。固态聚合过程分两个步骤进行，其中首先在180℃下通过熔融聚合制备预聚物，然后在聚丙交酯（PLA）的Tc附近进行后聚合。为了找到初始的SSP条件，测定了1-丙交酯与硬脂酸镁的熔融聚合的动力学曲线。根据动力学数据，发现熔融聚合相对于丙交酯是一阶的，这是通过使用1：500和1：5,000的催化剂/单体比例从1-丙交酯浓度对数变化与时间的对数线性关系来证明的。当催化剂含量增加到1：100时，由于在反应的早期快速传播，该关系失去了线性。从GPC数据可以看出，在为我们的SSP实验建立的条件下，PLA的分子量可以增加5-17倍。在两步固态聚合反应和已经报道的使用相同催化剂的熔融聚合反应之间的比较表明，SSP提供的聚合物的降解量要低得多。

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  • 来源
    《Journal of Polymers and the Environment》 |2013年第4期|1002-1008|共7页
  • 作者

    Alexandre Carneiro Silvino; Danielle Bonilha de Abreu Talina Martins; Aline da Costa Rodrigues; Marcos Lopes Dias;

  • 作者单位

    Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Av. Horacio Macedo, 2030, Centra de Tecnologia, Bloco J, CP 68525, Rio de Janeiro, RJ 21941-598, Brazil;

    Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Av. Horacio Macedo, 2030, Centra de Tecnologia, Bloco J, CP 68525, Rio de Janeiro, RJ 21941-598, Brazil;

    Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Av. Horacio Macedo, 2030, Centra de Tecnologia, Bloco J, CP 68525, Rio de Janeiro, RJ 21941-598, Brazil;

    Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Av. Horacio Macedo, 2030, Centra de Tecnologia, Bloco J, CP 68525, Rio de Janeiro, RJ 21941-598, Brazil;

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  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Solid state polymerization; Kinetics; Polylactide; Magnesium stearate; Biocompatible;

    机译：固态聚合;动力学;聚丙交酯;硬脂酸镁;生物相容性;

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