The Influence Of Annealing Temperature On The Structure And Properties Of CF/LDPE Porous Composites

To develop a novel controlling release system of nicotine,which can eliminate the effect of harmful toxic metals and carbonyl compounds in traditional e-cigarettes aerosols,carbon fiber(CF)filled low-density polyethylene(LDPE)porous composites was prepared by using a combined technique of injection molding and particulate leaching.Then,its injecting molding process,structure,conductivity,positive temperature coefficient(PTC)effect,self-heating property,nicotine release behavior,major metal concentration and carbonyl compounds concentration in nicotine gas were investigated.Study on the injecting molding process of the CF/LDPE porous composites shows that the most appropriate injecting process parameters of preparing the CF/LDPE porous composites are 75 MPa of the injection pressure,30 MPa of the packing pressure and 0.8s of the packing time.Study on the structure of the CF/LDPE porous composites shows that this porous composite is a hybrid of CF and LDPE,and this porous composite has no any chemical reaction during annealing.With the increase of annealing temperature,the obtained melting temperature and crystallinity degrees of their LDPE matrix increase.Many small irregular holes are found around the bare CF due to the extraction of PEO,and during annealing the softened LDPE can flow and spread on the surface of CF due to the excellent compatibility between LDPE and CF.CF/LDPE porous composites has interconnected pores with the main size of about 1?m,and the main pore size of this composites increase with the increase of annealing,but the effective porosity decrease with the increase of annealing.Study on the properties of CF/LDPE porous composites show that its properties can be obviously improved by annealing.With the increase of annealing temperature,the conductivity,PTC effect and self-heating property of this porous composites increase a lot.Study on the nicotine release behavior of CF/LDPE porous composites show that nicotine release concentration of this porous composite can be stable in a long time,and the nicotine release concentration of this porous composite can be obviously improved by annealing.With the increase of annealing temperature,the nicotine release concentration of this porous composites increase obviously.The harmful toxic metals generated by this porous composite are obviously less than traditional e-cigarettes aerosols.Formaldehyde is not found in the nicotine gas generated by this porous composites loaded nicotine and propylene glycol solution,but little glyoxal is found.All these results show that CF/LDPE porous composites can be used for a novel controlling release system of nicotine.