聚乙烯醇/明胶/纳米羟基磷灰石复合材料热塑加工性能研究

Thermal-Processing Properties of Poly( vinyl alcohol) /Gelatin /Nano-hydroxyapatite Composites

结合固相剪切碾磨技术(S3M),以胶原纤维(Col)在熔融挤出过程中原位降解成明胶(Gel),通过Gel与聚乙烯醇(PVA)分子间形成氢键复合增塑PVA,改善聚乙烯醇/纳米羟基磷灰石(PVA/n-HA)复合材料的热塑加工性能.采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)、示差扫描量热仪(DSC)、热重分析仪(TGA)、X射线衍射仪(XRD)和高压毛细管流变仪等研究了复合材料的结构与热塑加工性能.结果表明,通过S3M技术实现了n-HA在PVA基体中的均匀分散;FTIR表明Gel与PVA间形成了氢键作用和部分接枝反应;Gel和PVA分子间的氢键作用使PVA/Gel/n-HA复合材料的初始分解温度提高到287.6℃,改善了PVA的热稳定性,PVA的结晶度由纯PVA的58.2%降低到复合材料中的24.5%,使其熔点降低至130.5℃,拓宽了PVA/n-HA复合材料的加工范围,获得超过140 K的热塑加工窗口.Gel有效降低了PVA/nHA复合材料表观黏度,改善了PVA/n-HA复合材料的热塑加工性能.

Poly（ vinyl alcohol） /gelatin /nano-hydroxyapatite（ PVA /Gel /n-HA） composites were prepared based on solid state shear milling technology（ S3M） and plasticization of gelatin obtained by in situ degradation of collagen during extrusion. The structure and thermal-processing properties of the composites were characterized by scanning electron microscopy（ SEM）,Fourier transform infrared spectroscopy（ FTIR）,differential scanning calorimetry（ DSC）,thermogravimetric analysis（ TGA） and high pressure capillary rheometry. The results showed that n-HA particles were well dispersed in PVA based matrix by S3M technology. And strong hydrogen bonds formed between PVA and Gel,which may replace the self-inter and intra hydrogen bonds of PVA. The hydrogen bonds not only improved the thermal stability of PVA and increased the initial thermal decomposition temperature（ 287. 6 ℃） of PVA /Gel /n-HA composite,but also decreased the crystallinity degree（ about 24. 5%） of PVA so that the melting point（ 130. 5 ℃） was much lower than its initial thermal decomposition temperature,obtaining the thermal processing windows over 140 K.The gel significantly reduced the apparent viscosity of PVA /n-HA composites and improved the thermal processing properties,offering a new way to prepare PVA /n-HA bioactive composite.