Preparation And Properties Of Resin-based Black Shale Nanocomposites

Polymer/layered silicate nanocomposites have attracted attention for their rational utilization of resources,environmental protection and functionality.There are abundant and cheap black shale resources in Guangxi which often form corrosive acidic environment under warm and humid climate.Rational development of black shale can significantly reduce the cost of rubber and plastic products and reduce environmental disasters by replacing or partially replacing calcium carbonate and talcum powder.However,there are few reports on the development and utilization of black shale.Therefore,it is of great scientific significance and potential application value to carry out the research on the modification and utilization of black shale.In this paper,the morphology and composition of black shale were discovered by TG,SEM,EDS and XRD.Further more,Black shale/HDPE and black shale/PP composites were prepared by using surfactant and coupling agent for the first time,and their properties were studied.Meanwhile,the effect of calcined black shale and its effect on the properties of the composites were preliminarily discussed.The main research contents and conclusions are as follows:1.The microstructure and composition of black shale were analyzed in this paper.The results show that the black shale in Guilin is mainly composed of silica(51%),clay(39%),organic carbon(8%),and a small amount of pyrite.The average thickness of shale powder lamellar is 10.75 nm,which reflects the nano-stacked characteristics of black shale as sedimentary rock.The cationic exchange capacity was 8.53mmol/100 g by methylene blue method.It has a certain application space for inorganic nano-fillers used in plastics.2.High density polyethylene(HDPE)was filled with black shale of different mass fractions,and compatibilized by surfactant and coupling agent with different charge properties(anionic and cationic).The results show that the tensile strength is still higher than 22 MPa when the filling amount is 50,but the impact strength of the composites decreases more seriously.With the same coupling agent,the properties of anionic surfactant system composites are better than cationic surfactant system,and the relative length of alkyl chain in cationic surfactant system has different effects on the tensile properties and impact properties of composites The addition of black shale has little effect on the thermal stability of the composites,and the thermal decomposition kinetic data indicates that the thermal decomposition reaction of the composite material is a first-order reaction.3.Polypropylene matrix composites were also prepared with different amount of black shale and compatibilizer.The impact strength of PP matrix composites increases and the tensile strength decreases.The thermal stability of the material still has no obvious change.The influence of cationic surfactants on the properties of the composites is the same as that of high-density polyethylene composites,and the influence of anionic surfactants depends on the different functional groups.Thermal decomposition of composites is also a first-order reaction.4.The small molecules of oil in black shale seriously hinder the effective combination between shale and coupling agent,and the decomposition of pyrite in processing seriously affects the health of workers.In this paper,thermal cracking was used to process black shale for the first time.The effects of calcination on the composition and morphology of shale were studied by XPS,FTIR,SEM,etc.,and thermal cracking shale /HDPE composites were prepared.The results show that the organic matter and pyrite in the black shale are removed by calcination,and the carbon content of the black shale decreases from 35.95% to 6.98% after calcination,while the sulfur atom concentration can not be measured.The shale retains the layered structure and has lamellar fragmentation phenomenon,and XRD shows that the shale spacing is slightly reduced.The impact strength of the calcined shale /HDPE composite material is significantly improved.The microstructure of the cross section of the composite material shows that there are a lot of interface bonding between the calcined shale and HDPE,while the natural shale and HDPE are completely separated.The thermal cracking of black shale and the preparation of its composite materials provide a new idea for improving the utilization value of black shale,which is of great significance to the exploitation and mine remediation of black shale.