Ultrasonic Devulcanization of Scrap Tire Rubbers: Science and Engineering

本研究的主要目的是为轮胎胶粉超声回收新技术的基础知识和高性能设备的设计奠定基础。在早期的研究中已经发现，通过在特殊设备上应用一定水平的超声波幅度，增强和非增强硫化弹性体中的三维网络可以被打破，从而在短时间内达到几秒钟量级的脱硫化。作为最理想的结果，经超声波处理的GRT变软，从而使橡胶能够单独或与原始橡胶和塑料共混进行再加工、成形和再硫化。本研究概述了一系列任务：(1)设计用于GRT连续超声波脱硫化的新设备；(2)鉴定强超声波对模型丁苯橡胶、天然橡胶、丁二烯橡胶和三元乙丙橡胶及其混合物的结构和性能的影响；(3)揭示炭黑对每个模型橡胶及其混合物中超声波诱导的机械力化学反应的影响；(4)研究每种型号橡胶硫化胶的超声波处理对其与未硫化橡胶共混物再硫化时力学性能的影响；(5)建立最佳工艺条件，使人们能够获得具有高机械性能的硫化GRT基材料；(6)发展橡胶网络降解理论，并开发计算机模拟反应器，以帮助扩大工艺规模。

The main objective of this research is to develop basic knowledge and to design the high capacity equipment for the new ultrasonic technology of recycling ground tire rubber (GRT). It has been discovered in the earlier research that through the application of certain levels of ultrasonic amplitudes in special devices, the three-dimensional network in reinforced and non-reinforced vulcanized elastomers can be broken down leading to devulcanization within a short period of time of the order of a few seconds. As the most desirable consequence, ultrasonically treated GRT becomes soft thereby enabling the rubber to be reprocessed, shaped, and revulcanized alone or in blends with virgin rubbers and plastics.The study outlines a series of tasks enabling: (1) the design of new equipment for continuous ultrasonic devulcanization of GRT; (2) the identification of the effect of powerful ultrasound on structure and properties of model unfilled and carbon black filled styrene-butadiene, natural, butadiene, and EPDM rubber vulcanizates and their mixtures which are the constituents of GRT; (3) to reveal the effect of carbon black on the ultrasonically induced mechanochemical reactions in each model rubber and their mixtures; (4) to investigate the effect of ultrasonic treatment of each model rubber vulcanizates on the mechanical properties of their blends with virgin rubber upon revulcanizations; (5) to establish the optimal processing conditions enabling one to obtain the devulcanized GRT-based materials with high mechanical properties; (6) to develop the theory of rubber network degradation and to develop computer simulations of the reactors as an aid to scaling the process.