钨酸铅/天然橡胶纳米复合材料制备及其γ射线屏蔽性能

Preparation and γ-rays Shielding Properties of PbWO_4/Nature Rubber Nanocomposites

将钨酸铅(PbWO_4)粒子球磨至纳米尺度,采用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对其进行表面改性,并与天然橡胶(NR)机械共混,制备出橡胶纳米复合材料,运用扫描电镜(SEM)、X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、接触角(CA)测量仪、电子万能试验机和高纯锗γ谱仪系统对其形貌及性能进行了表征与测试。结果表明:KH570成功接枝到PbWO_4表面;与未改性PbWO_4相比,改性后PbWO_4在NR中分散更为均匀,复合材料力学性能及γ射线屏蔽性能更为优异;PbWO_4与NR填充质量比为50∶100时,力学性能最佳(拉伸强度为30.6 MPa),相比于填充质量比为60∶100时,γ射线屏蔽率仅下降了1.8%,因此PbWO_4与NR最佳配料比为50∶100。

The nanoscale PbWO4 particles were modified with saline coupling agent（KH570） after ballmilling,then the modified PbWO4 particles were blended with natural rubber（NR） to prepare PbWO4/NR Nanocomposites. The structures of modified PbWO4 were characterized by SEM,XRD,FT-IR,CA techniques. Meanwhile,the mechanical and γ-rays shielding properties of the composite materials were measured by electronical universal testing machine and 3 ＂ x3＂ Ge γ spectrometer system. The results show that KH570 is successfully grafted into the surface of PbWO4. And the modified PbWO4 were uniformly dispersed in the NR matrix. Besides,compared with the unmodified PbWO4/NR materials,the modified PbWO4/NR materials have better mechanical and γ-rays shielding properties. Compared with the filler mass ratio of 60∶ 100,the mechanical property（tensile strength is about 30. 6 MPa） reaches the maximum with 50 phr of modified PbWO4 particles and γ-ray shielding rate decreasing by only 1. 8%,so the best ingredients mass ratio of PbWO4 and NR was 50∶ 100.