Abstract:
Chemical recycling of polyurethanes can be realized in several different ways, but the most important methods are glycolysis and glycerolysis. Both methods permit recovery of polyols (when the process is realized with the mass excess of depolymerizing agent) or substitutes of polyols, which contain urethane moieties in the main chains and terminate mainly in hydroxyl groups (when the process is realized with the mass excess of depolymerized polyurethane). Oligomeric products with urethane groups in the chemical structure can also be used as modifiers of rubber mixtures and vulcanizates. The main aim of the presented work is to study the effect of polyurethane glycerolysate on the performance of natural rubber mixtures and vulcanizates. The influence of the modifier on the vulcanization kinetics and swelling of rubber mixtures, and the thermo-mechanical and mechanical properties of rubber vulcanizates, was studied. The prepared materials were also subjected to accelerated thermal aging in air. It was found that polyurethane glycerolysate affects the vulcanization process of rubber mixtures (for example, promotes the activation of vulcanization) and acts as an antidegradant under thermoxidative conditions (higher stability of mechanical properties was observed in comparison to a reference sample without modifier). The obtained results show that chemical recycling products can be valuable modifiers of natural rubber mixtures and vulcanizates, which extends the possible applications of polyurethane chemical recycling products.
摘要:
聚氨酯的化学回收可以通过几种不同的方式实现,但最重要的方法是糖酵解和甘油解。两种方法都允许回收多元醇(当使用质量过量的解聚剂实现该过程时)或多元醇的替代品,其在主链中含有氨基甲酸酯部分并且主要终止于羟基(当用质量过量的解聚聚氨酯实现该过程时)。在化学结构中具有氨基甲酸酯基团的低聚产物也可用作橡胶混合物和硫化橡胶的改性剂。所提出的工作的主要目的是研究聚氨酯甘油酯对天然橡胶混合物和硫化橡胶性能的影响。改性剂对橡胶混合物的硫化动力学和溶胀的影响,以及硫化橡胶的热机械性能,被研究过。所制备的材料也在空气中进行加速热老化。发现聚氨酯甘油酯会影响橡胶混合物的硫化过程(例如,促进硫化的活化),并在热氧化条件下充当抗降解剂(与没有改性剂的参考样品相比,观察到更高的机械性能稳定性)。结果表明,化学回收产品可以作为天然橡胶混合物和硫化胶的有价值的改性剂,这扩展了聚氨酯化学回收产品的可能应用。