Blending Polyurethane Thermosets Using Dynamic Urethane Exchange
Blending Polyurethane Thermosets Using Dynamic Urethane Exchange
复制标题
使用动态聚氨酯交换混合聚氨酯热固性材料
DOI：
10.1021/acs.macromol.1c01910
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发表时间：
2021
期刊：
影响因子：
5.5
通讯作者：
Dichtel, William R.
中科院分区：
文献类型：
--
作者：
Swartz, Jeremy L.;Sheppard, Daylan T.;Haugstad, Greg;Dichtel, William R.
回收交联聚氨酯（PU）是通过机械或化学工艺完成的，这些工艺是能源密集型的或生产价值较低的塑料。聚合物再循环方法显著地不耐受聚合物混合物，然而再加工和使两种或更多种交联PU相容在一起的能力将使该方法更适合于混合废物流，同时提供调整再循环聚合物产物的性质的机会。在这里，我们使用双螺杆挤出将刚性聚酯PU和软质聚醚PU共混，以根据进料组成产生具有可调机械性能的材料。它们的材料性能进行了比较，压缩成型的再加工的共混物和共混物的单体混合之前，合成。挤出材料显示出与新制备的共混物相似的机械和热性能，并且与通过压缩成型再加工的样品相比具有更高的机械性能值。通过原子力显微镜使用相成像观察共混物的形态，以表明与压缩成型的共混物相比，挤出材料中的相分离较少。这些材料的机械性能是可调的，从软到弹性体到刚性的基础上的饲料组成，这种可调性证明了通过四个连续的再加工周期，通过这些机械性能稳定地从刚性到软的变化，通过纳入软聚醚PU材料的量增加。这种用于再加工混合废物的共混方法使不同的PU相容，并提供了一种调整PU产品机械性能的方法，即使是从不同组成的废物流开始。因此，该工艺代表了聚合物再加工的一种有趣的新方法。
Recycling crosslinked polyurethanes (PUs) is accomplished through mechanical or chemical processes that are energy-intensive or produce plastics of lesser value. Polymer recycling processes are notably intolerant of polymer mixtures, yet the ability to reprocess and compatibilize two or more crosslinked PUs together will make this process more amenable to mixed waste streams while offering an opportunity to tune the properties of the recycled polymer products. Here, we blend a rigid polyester PU and a soft polyether PU using twin-screw extrusion to yield materials with tunable mechanical properties based on the feed composition. Their material properties were compared to those of compression-molded reprocessed blends and blends where the monomers were mixed prior to synthesis. The extruded materials showed similar mechanical and thermal properties to newly prepared blends and had higher-value mechanical properties compared to the samples reprocessed via compression molding. The morphologies of the blends were observed using phase imaging via atomic force microscopy to show that there is less phase separation in the extruded materials compared to compression-molded blends. The mechanical properties of these materials were tunable from soft to elastomeric to rigid based on the feed composition, and this tunability was demonstrated through four consecutive reprocessing cycles, through which the mechanical properties were steadily varied from rigid to soft by incorporating increasing amounts of soft polyether PU material. This blending method for reprocessing mixed waste compatibilizes different PUs and provides a means to tune the mechanical properties of a PU product, even if starting from waste streams of varying compositions. As such, this process represents an intriguing new approach for polymer reprocessing.
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影响因子：
5.5
作者：
Todd, Alexander D.;McEneany, Ryan J.;Hillmyer, Marc A.
通讯作者：
Hillmyer, Marc A.
Szycher 聚氨酯手册，第二版
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
M. Szycher;P. D.
通讯作者：
P. D.
影响因子：
18.2
作者：
Sheppard, Daylan T.;Jin, Kailong;Dichtel, William R.
通讯作者：
Dichtel, William R.
影响因子：
5.5
作者：
Kloxin, Christopher J.;Scott, Timothy F.;Adzima, Brian J.;Bowman, Christopher N.
通讯作者：
Bowman, Christopher N.