疏水球状碳酸钙的制备、表征及对聚丙烯力学性能的影响

以十二碳醇磷酸酯(DDP)为改性剂, 采用碳化法制备了分散性良好的球状碳酸钙粒子. 通过FESEM, XRD, FTIR及活化度和接触角测试对产物进行了表征. XRD分析结果表明, 随着DDP添加量的增加, 所得CaCO3由方解石型向文石型转变. FTIR结果表明, 改性剂与碳酸钙表面是以化学键合和物理吸附方式相结合. 当DDP含量达到2%时, 接触角为120.43°, 活化度达到99%, 碳酸钙粒子由亲水性转变为完全疏水性. 考察了反应温度和DDP含量对产物形貌与结晶行为的影响, 并对改性机理进行了初步探讨. 将产品填充到聚丙烯(PP)中, 测定了PP的力学性能.

Preparation,Characterization of Hydrophobic Spherical CaCO3 Particles and Influence on Properties of Polypropylene

Monodisperse hydrophobic spherical CaCO3 particles were prepared by carbonation in the presence of dodecyl dihydrogen phosphate(DDP).The surface property of CaCO3 particles was transformed from hydrophilic to hydrophobic when the mass ratio of DDP to CaCO3 changed from 0 to 2%.X-Ray diffraction(XRD) patterns showed that the crystal form of CaCO3 particles was turned from calcite to aragonite with increasing the dosage of DDP in the reaction.FTIR spectra indicated the existence of the alkyl groups from the DDP in the products.When the mass ratio of DDP to CaCO3 was 2%,the active ratio reached 99% and the contact angle of modified CaCO3 particles was 120.43°.Simultaneously,the effects of the reaction temperature and the dosage of DDP on the morphology and behaviors of aragonite crystals were discussed.When the schematic illustration on the formation process of hydrophobic spherical CaCO3 particles was discussed in the work.When the obtained modified CaCO3 was added into polypropylene(PP),the mechanical properties and processabilities of PP improved greatly.