Preparation And Barrier Properties Of Graphene/Hdpe Nanocomposites

Although high-density polyethylene（HDPE）has many excellent properties,it is used as oil pipeline material,and its gas barrier properties are not high,which greatly limits its application.How to further improve the gas barrier properties of HDPE and maintain good physical and mechanical properties,has always been the focus of composite product developers.In this paper,the high-barrier nanofiller graphene oxide（GO）is mixed with HDPE to improve the gas barrier properties of nanocomposites.However,there are two difficulties in mixing the two.First,the compatibility between GO and HDPE is very high.Poor;second,GO is easy to agglomerate in the HDPE matrix,and it is difficult to disperse uniformly.Therefore,this paper improves the mixing effect by improving the process method and GO functionalization modification,and then obtains GO/HDPE nanocomposites with high barrier properties.First,GO/HDPE nanocomposites were prepared by the layered dispersion method,and the effect of GO content on the properties of nanocomposites was explored.The experimental results showed that with the increase of GO content,the crystallinity and thermal decomposition temperature of the nanocomposites gradually decreased,the tensile strength and bending properties decreased slightly,but the impact strength and elongation at break decreased significantly.When the GO content was c wt%,the O₂barrier properties of the nanocomposites improved the most by 31%.Then,ODA-GO/HDPE nanocomposites were prepared by using octadecylamine（ODA）functionalized modified GO（ODA-GO）by melt blending,and the effect of ODA-GO content on the properties of nanocomposites was explored.The experimental results show that when the ODA-GO content is e wt%,the crystallinity of the nanocomposite is up to 96.4%,and the thermal decomposition temperature is also significantly increased.Compared with the mechanical strength of pure HDPE,the tensile strength and flexural properties of the nanocomposites are almost unchanged,only the elongation at break is reduced,but the impact strength is significantly enhanced.When the ODA-GO content is a wt%,the O₂barrier properties of the nanocomposites are improved the most by 50%;when the ODA-GO content is c wt%,the helium（He）barrier properties of the nanocomposites are improved the most,an increase of 13%.Finally,maleic anhydride grafted polyethylene（PE-MAH）was used as a compatibilizer between GO and HDPE,PE-MAH and GO were first put into an internal mixer for blending modification,and then melt blending was used.GO/PE-MAH/HDPE nanocomposites were obtained,and the effect of PE-MAH content on the properties of nanocomposites was explored.The experimental results showed that when the GO content was c wt%,the crystallinity and mechanical properties of the nanocomposites changed little with the increase of PE-MAH content,while the thermal decomposition temperature slightly decreased.When the PE-MAH and GO contents wereδwt%and c wt%,respectively,the O₂barrier properties of the nanocomposites were improved the most by70%.The three methods provided in this paper not only provide more research ideas for the preparation of other high gas barrier GO/polymer nanocomposites,but also are expected to realize the industrial application of high gas barrier GO/HDPE nanocomposites.