Carbon Foam From Bamboo Tar And It's Performence

Carbon foam is a kind of porous carbon materials which expendedrapidly in the beginning of the twentieth century, because of itsporousness, small density, high strength, adjustable thermal conductivityand electrical conductivity, excellent physical and chemical stability, andmany other advantages, it widely used in many materials such as catalystsupports, heat exchangers, insulation system and so on. Along with thefurther study in recent years, this new materials gradually put into use inthe military defense and aerospace materials, such as soldier protectionsystem, the frames and the base of the telescope. But along with thedevelopment of science and technology, coal, oil and other fossil energyare constantly decreasing, the gradually disappear of these preciousnon-renewable energy force people to find a new renewable resources toreplace these declining non-renewable energy.Bamboo tar is a byproduct of Bamboo charcoal which formed inthe process of the bamboo charcoal carbonization from bamboo, but alarge number of complex organic compounds of its composition reducethe usable value of their own. Along with the production of bamboocharcoal, bamboo tar yield increases year by year, a lot of abandonedbamboo tar not only polluting environment, but also threatening people's health. After some characterizations for Bamboo tar composition, wefind bamboo tar contains large amounts of phenol and phenolcompounds, besides, it also contains a number of other small moleculessuch as alkanes and aromatic hydrocarbons, These are very similar tothe pitch component, and provide a certain theoretical for COPNA resinbased from bamboo tar. COPNA resin is the middle substances betweenorganic matter and carbon materials, the composition and its polycyclicstructure decides their higher carbonization yield, which effectivelyillustrates the possibility of the COPNA resin as the precursor of carbonmaterials. This provides a very strong proof of carbon foams preparationfrom bamboo tar, making this idea based on evidence.PXG was chosen as cross-linking agent, and p-toluene sulfonicacid as catalyst to prepare COPNA resin, we use FT-IR and TG tocharacterize the reaction and resin, and analyze to know the influence ofPXG proportion, reaction temperature and reaction time to the COPNAresin. The study found that the synthesis COPNA resin is a cationsubstitution reaction firstly, when PXG proportion accounted for60%to80%of the quality of bamboo tar, it will promote the reaction. Theoptimum reaction temperature is in130~160°C; reaction time is in6.5~7h is more appropriate for getting the B-stage COPNA resin. A stageCOPNA resin have low cross linkage,we treated it via oxidation toimprove its comprehensive utilization, and research the effect of theoxidation temperature and oxidation time to A stage COPNA resinthrough FT-IR and TS, TS-PI, PS content test. Research found that itwill oxidize faster when the oxidation temperature is85℃, and theappropriate oxidized time is in20~30h relatively, After oxidation, theresin's TI content reduced sharply, PS content increase dramatically, and then obtain a resin which have the same amount of TS-PI and PS. Ithas a great role to promote the resin be further processed into carbonmaterials. In addition, from the TG test, we know the B-stage resin losslarge weight at300℃and430℃respectively, while C-stage COPNAresin thermal decomposition temperature is430℃, which indicate thatthe C stage resin heat-resistant temperature of430℃.B stage COPNA resin and oxidized A stage COPNA resin frombamboo tar was foamed through the limited space method, the carbonfoam was obtained after the high temperature carbonization, and theeffect of resin's mass, the proportion of crosslinking agent, foamingtemperature, carbonization temperature and soluble composition of resinwere analyzed. Study found that the appropriate resin quality is in12~20g, a carbon foam with better comprehensive performance will gotwhen the mass of PXG is60%~80%of the bamboo tar, the betterformation temperature is in300~400℃, the compression strengthincreases with rising temperature, In addition, mechanism of theformation was explored and found the TS of the resin plays a role ofmaking holes, TS content has a great impact on the uniformity and porediameter of holes, TI-PS main effect is adhesive composition of the PS,While the content of the PI has a major impact on the compressionstrength.A kind of carbon foams with good Comprehensive performancecould be obtained only when these three contents have an appropriateproportion. After optimizing the above conditions, we obtained a kind ofcarbon foam with high compression strength and thermal insulationmaterials, it's density is0.56g/cm3, pore diameter is in50~100μ m, compression strength is13.6MPa, and Thermal conductivity is0.54W/m K.