AIM中橡胶相交联密度对AIM/PMMA共混物性能的影响

The Influence of Rubber Cross-Linking Density of AIM on Properties of AIM/PMMA Blends

采用乳液聚合方法制备了四种不同交联密度且粒径及折光指数可控的丙烯酸酯类冲击改性剂(AIMs),考察了AIMs中橡胶相的交联密度变化对AIM/PMMA共混物力学性能及光学性能的影响。结果表明,AIM/PMMA共混物的冲击强度随AIM中交联剂用量的提高呈先上升后下降趋势,当AIM的橡胶相交联剂含量为2%(质量分数,下同)时,AIM/PMMA共混物的最大裂纹引发能(Kmax)、裂纹增长能(Uprop)及冲击强度均达到最大值,与纯聚甲基丙烯酸甲酯(PMMA)相比较,其冲击强度提高了5倍,且光学性能没有明显下降。结合共混物的冲击强度与形变区的扫描电镜(SEM)观察,可见断裂过程中此种AIM橡胶粒子的空洞化能够有效地促进基体树脂的能量吸收。

Four kinds of acrylic impact modifiers（AIMs） with different rubber cross-linking density were synthesized by emulsion polymerization,of which diameter and refractive index can be controlled.The effect of different rubber cross-linking density on mechanical and optical properties of AIM/PMMA blends was investigated.It shows that impact strength of AIM/PMMA blends increases at first and then decreases with cross-linking agent raising,maximum crack initiation energy（Kmax）,crack propagation energy（Uprop） and impact strength of AIM/PMMA blends get to maximum when moderate rubber cross-linking agent content of AIM,2%,is adopted.In comparison with pure polymethylmethacrylate（PMMA）,impact strength is improves by five times,and the change of optical property is not remarkable.According to the results of impact tests and scanning electron microscope（SEM） observation of deformation zone of AIM/PMMA blends,the rubber particles cavitation of AIM is beneficial to improve energy-absorbing of matrix resin.