PMMA-CI复合磁性粒子的磁流变液性能研究

Study on the properties of the MRF collocated by PMMA-CI composite magnetic particles

采用自由基聚合法，通过改变MMA与CI的质量配比制备不同结构的PMMA-CI复合磁性粒子。并对PMMA-CI复合磁性粒子的表面形貌、粒度、密度以及热失重进行表征。考察了复合磁性粒子的结构变化对其磁流变液沉降稳定性和流变学性能的影响。结果表明：复合磁性粒子与CI粒子相比，其磁流变液的沉降稳定性有所提高，但是流变学性能下降；提高MMA与CI的质量配比会使复合磁性粒子粒径和高分子包覆量逐渐增大、密度减小，粒子的这种结构变化可以改善磁流变液的沉降稳定性，而流变学性能会逐渐降低。

In this paper, different structures of PMMA-CI composite magnetic particles are prepared by changing the proportion of MMA and CI by radical polymerization. The morphology, granularity, density and TG quantity of the particles are characterized. The influences of structures changing of the composite magnetic particle on the sedimentation stability properties and the rheological properties of their MRF are studied. The result shows sedimentation stability properties of the PMMA-CI composite magnetic particles, comparing to the CI particles, will be better, but the rheological properties will be worse. Rising the proportion of MMA and CI will increase particle granularity and the quantity of the macromolecule enwrapping, and will reduce the density. This type structure changing of the particles will advance the sedimentation stability properties and reduce the rheological nronerties of their MRF.