Basic Studies of Continuous Ultrasonic Devulcanization of Rubbers

该项目的主要目标是开发基于科学的硫化弹性体连续脱硫新技术的基础知识。众所周知，具有三维网络的硫化弹性体在热和/或压力的作用下不能流动。已经发现，通过在特殊装置中施加一定水平的超声波振幅，在压力和可选的热量的存在下，硫化弹性体的三维网络可以在一秒或更短的时间内被分解。作为最理想的结果，超声处理的硫化橡胶变得柔软，从而使该材料能够以类似于未硫化弹性体所采用的方式进行再加工、成型和再硫化。该研究概述了一系列实验，使我们能够(i)确定多硫化物、单硫化物和碳-碳交联对超声波脱硫的能力；（二）确定脱硫工艺的最佳条件；（iii）评估硫化橡胶的流变性能；（四）测定用硫化橡胶制成的再硫化橡胶制品的机械性能。硫化弹性体（主要是废旧轮胎）的回收利用已成为一个重大的环境和社会问题。橡胶再生新技术的开发将通过工艺优化和新发现对进一步扩大再生技术基础产生重大影响。

9312249 Isayev The main objective of the project is to develop basic knowledge for a new science-based technology of continuous devulcanization of vulcanized elastomers. It is well known that vulcanized elastomers having a three-dimensional network cannot flow under the effect of heat and/or pressure. It has been discovered that through the application of certain levels of ultrasolic amplitudes in special devices in the presence of pressure and optionally heat, the three-dimensional network of vulcanized elastomer can be broken down within a short period of time on the order of one second or less. As a most desirable consequence, ultrasonically treated vulcanized rubber becomes soft, thereby enabling this material to be reprocessed, shaped, and revulcanized in a manner similar to that employed with unvulcanized elastomer. The study outlines series of experiments enabling us to (i) identify an aptitude of polysulfidic, monosulfidic, and carbon- carbon crosslinks to ultrasonic devulcanization; (ii) to establish optimal conditions for the devulcanization process; (iii) to evaluate the rheological properties of devulcanized rubbers; and (iv) to measure the mechanical performance of revulcanized rubber products made of devulcanized rubber. The recycling of vulcanized elastomers (primarily used tires) has become a major environmental and social issue. The development of a novel technique for the reclaiming of rubber will have a significant impact on the further expansion of a recycling technology base through the optimization of the process and new discoveries.