A comparison of adhesive polysulfides initiated by garlic essential oil and elemental sulfur to create recyclable adhesives
A comparison of adhesive polysulfides initiated by garlic essential oil and elemental sulfur to create recyclable adhesives
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DOI：
10.1039/d2py00418f
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发表时间：
2022-07-11
影响因子：
4.6
通讯作者：
Jenkins, Courtney L.
中科院分区：
文献类型：
--
作者：
Davis, Anthony E.;Sayer, Kyler B.;Jenkins, Courtney L.
尽管粘合剂起源于天然材料，但大多数胶水是由石油基产品形成的。然而，许多天然粘合剂缺乏与合成胶水竞争的强度。因此，需要强有力的、可持续的替代品。这里提供的数据建立在先前的工作基础上，该工作将石油副产品元素硫和由烯丙基硫化物组成的大蒜精油（GEO）结合在一起，以制造粘合剂。在这里，我们已经证明了硫和GEO都可以在160摄氏度下通过形成硫自由基引发另一种石油副产品双环戊二烯和各种天然单体的聚合。除了使用天然单体和石油副产物之外，这些方法是无溶剂的，并且具有高原子经济性，限制废物形成，并且符合绿色化学的许多原则。大部分工作集中在确定每种硫源对聚合和粘合的影响。一个家庭的聚合物与不同的S：GEO：单体的比例和特征，以确定其化学和材料性能的差异。尽管反应机制相似，但硫倾向于更快地分解，并产生更具延展性和更容易再加工的材料。GEO反应较慢，导致在粘附体表面上发生更多的聚合，产生具有更高的最大粘附强度但较低的粘附功的更脆的聚合物。两种聚合物均表现出有效的粘合剂可回收性。总的来说，天然油和石油副产品的组合被结合在一起，制造出廉价、可持续、可回收的粘合剂。
Despite adhesives having their origins in natural materials, most glues are formed from petroleum-based products. However, many natural adhesives lack the strength to compete with synthetic glues. Therefore, strong, sustainable alternatives are needed. Data presented here build on prior work that combines elemental sulfur, a petroleum byproduct, and garlic essential oil (GEO) which is composed of allyl sulfides, to make adhesives. Here, we have demonstrated that both sulfur and GEO can initiate polymerization at 160 degrees C with another petroleum byproduct, dicyclopentadiene, and a variety of natural monomers through the formation of sulfur radicals. In addition to using natural monomers and petroleum byproducts, these processes are solvent free and have high atom economy, limiting waste formation, and meeting many principles of green chemistry. Much of this work has focused on determining the effect of each sulfur source on polymerization and adhesion. A family of polymers were created with varied S : GEO : monomer ratios and characterized to determine differences in their chemical and materials properties. Despite similarities in the reaction mechanism, sulfur tends to polymerize more rapidly and create materials that are more ductile and more easily reprocessed. GEO is slower to react causing more polymerization to take place on the adherend surface yielding a more brittle polymer with higher maximum adhesion strength but lower work of adhesion. Both polymers exhibited effective adhesive recyclability. Overall, a combination of natural oils and petroleum byproducts were combined to make inexpensive, sustainable, recyclable adhesives.