酚胺仿生修饰埃洛石制备耐老化天然橡胶的研究

Study on Biomimetic Modification of Halloysite with Catechol/polyamine to Prepare Aging Resistant Natural Rubber

利用纯天然的埃洛石纳米管作为主体,将防老剂4010负载到管内,并通过酚胺修饰技术进行表面处理,制造出具备功能性的填充剂,进而生产出具有抗老化特性的天然橡胶。采用热重分析计算埃洛石与防老剂4010的投料质量配比为1∶2时可得到6.507%的最大负载率,添加40份PCPA/HNTs-4010和1.5 g游离防老剂4010的橡胶在90℃老化7 d后断裂伸长率为560%,拉伸强度为15.4 MPa,相比添加相同剂量游离防老剂4010的天然橡胶分别提升70%和2.9%,都比添加相同剂量HNTs-4010的天然橡胶总体性能好。接触角分析测量结果显示,酚胺修饰时间为24 h时对HNTs-4010的包覆更紧密,证明酚胺仿生修饰能够改善埃洛石与天然橡胶的相容性。扫描电镜图显示,随着老化时间增加,添加PCPA/HNTs-4010的橡胶喷霜现象比HNTs-4010减弱,可见埃洛石纳米管经过PCPA包裹后,防老剂的释放更加缓慢,制备而成的橡胶复合材料喷霜现象得到有效抑制。

Using natural illite nanotubes as the main body,the antioxidant 4010 was loaded into the tubes and surface-modified with catechol/polyamine through a surface modification technique,thus manufacturing functional fillers and producing natural rubber with anti-aging properties.The thermogravimetric analysis calculated that the feed ratio of illite to 4010 antioxidant was 1∶2 when the maximum loading rate of 6.507%was obtained.The addition of 40 parts of PCPA/HNTs-4010 and 1.5 grams of free 4010 antioxidant to the rubber resulted in a tensile strength of 15.4 MPa and a tensile elongation of 560%after aging at 90℃for 7 days,which were 70%and 2.9%higher than those of the natural rubber containing the same amount of free 4010 antioxidant,respectively.The overall performance of the rubber containing PCPA/HNTs-4010 was better than that of the rubber containing the same amount of HNTs-4010.The contact angle analysis measurement results showed that the wrapping of phenolamine on HNTs-4010 was more tightly when the modification time was 24 hours,proving that catechol/polyamine modification can improve the compatibility of illite and natural rubber.The scanning electron microscope images showed that as the aging time increased,the frosting phenomenon of the rubber containing PCPA/HNTs-4010 was less severe than that of HNTs-4010,indicating that the release of the antioxidant was slower after the illite nanotubes were wrapped by PCPA,and the frosting phenomenon of the rubber composite material was effectively suppressed.