聚乙烯醇/β-磷酸三钙复合材料的微型注塑加工研究

Micro Injection Molding of Poly (vinyl alcohol)/ β -Tricalcium Phosphate Composites

采用分子复合和增塑的方法制备了聚乙烯醇/β-磷酸三钙(PVA/β-TCP)复合材料,利用微型注塑机成功实现了复合材料的微型注塑。通过高压毛细管流变、X射线衍射(XRD)、扫描电子显微镜(SEM)、差示扫描量热仪(DSC)等方法综合评价复合材料的流变性能、充模性能、结晶性能等。结果表明,在高剪切速率下,复合材料拥有较低的剪切黏度,具有较好的流动性。微型注塑样品良好的复制了模具的精细结构,充模完整,样品最薄处仅0.29 mm,质量仅0.02 g。微型注塑过程中的强剪切作用有利于分子链的取向,微型注塑样品的拉伸强度达到118 MPa,且热塑加工过程及微型注塑过程中的强剪切作用并没有破坏β-TCP的结晶结构及其赋予的生物活性。

The polyvinyl alcohol(PVA)/ β -tricalcium phosphate( β -TCP)composites were prepared by complexation and plasticization,and its micro-injection molding was successfully realized.The rheological properties,mold filling properties and crystallization of PVA/ β -TCP composites were evaluated by high-pressure capillary rheology,X-ray diffraction(XRD),scanning electron microscope(SEM),and differential scanning calorimeter(DSC).The results show that at high shear rates,the composite material had a lower shear viscosity and very good fluidity.The micro-injection sample replicates the mold structure well,and the filling is relatively complete.The thinnest part of the sample is only 0.29 mm,and the mass is only 0.02 g.The strong shear stress in the micro-injection process is conducive to the orientation of the molecular chain.The tensile strength of the micro-injection sample could reach 118 MPa.The experiment proves that the strong shear during the thermoplastic processing and micro-injection process could not destroy the biological activity of β -TCP in the physiological environment.