| Cellulose is a kind of natural polymer that has the biggest reserves,the most widely distribution,better biodegradation and regeneration in nature.Nanocrystalline cellulose(NCC)not only remains all characteristics of cellulose,but also has more excellent properties due to its unique effects of nanotechnology.Cellulose molecules are manipulated its structure and supramolecular aggregation with designing and assembling stable multiple patterns in nano-meter size range,creating excellent new functional nanomaterials with high value-added are the frontier and hotspots of nano-cellulose science field.This paper that used reed pulp as raw material used different cocatalyst acid hydrolysis method to prepare controllable structure NCC,on basis of which four types of NCC functional composites were prepared,and their structure were characterized,their performance were tested respectively.By discussing the preparation of NCC via three cocatalyst sulfuric acid hydrolyzing reed pulp,with yield and grain size as an indicator and by the instrumental analysis,we could know that NCC retained the basic chemical composition of raw materials,the three cocatalyst could effectively shorten the hydrolysis time,SMS was the best NCC structure controllable promoter,and its optimum value was:Added m(SMS)/m(Reed)= 10%,reaction temperature was 50?and reaction time was 3.Oh.By discussing different mass ratio of NCC and PEG,different volume ratio of water and 1,4-dioxane,different solvent to prepare NCC/PEG aerogel,and its detection and performance analysis,we know different PEG mass ratio,different volume ratio of water and 1,4-dioxane and different solvent could obtain different nanoporous structures NCC/PEG aerogel;NCC/PEG aerogel has an unique performance,such as high specific surface,higher enthalpy of phase change,good thermal stability,easy to be wet and instant dispersed in water or DMF,which has fine performance and broad market of nanocrystalline cellulose matrix aerogel.Using the TDI as a bridge,we could get NCC/PEG graft solid-solid phase transition composites by fixing the PEG on NCC skeleton with chemical bonding,and we discussed the percentage content of PEG and n(-CNO):n(-OH)ratio's energy storage performance impact for composite phase change materials,the results show that weight percentage of PEG in composition and n(-CNO):n(-OH)had obvious effect on the phase transition temperature,energy storage and phase change enthalpy for NCC/PEG,which with different phase change enthalpy,different phase transition temperature and well thermostabilization can be obtained by means of weight percentage of PEG and n(-CNO):n(-OH).NCC/magnetic nanospheres were in-situ synthesized with the many active point and emulsified performance of NCC,the results show that the magnetic particles was nano-Fe3O4,which was fully dispersed in NCC through chemical bonding and physical adsorption with NCC,NCC/magnetic nanospheres were in-situ synthesized under better condition with NCC concentration of 1.0%,stirring speed of 500 r/min,total iron ion concentration of 0.0065 mol/L(the mass fraction of magnetic particle theory quality is 5%to NCC)and it has magnetic properties of magnetized strength of 73.39 emu/g(per gram ash)and coercivity of 20.1 Oe.NCC/PLA/PEG grafted copolymer and PLA/PEG graft copolymers were achieved by lactide ring-opening polymerization,and with a small amount NCC of the NCC/PLA/PEG graft copolymers had a higher thermal stability and energy storage efficiency than PLA/PEG graft copolymers,the results show clearly that PLA/PEG thermal stability and energy storage efficiency can be effectively improved by effects of nanotechnology of NCC. |
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