Rearch Of Green Environmental Protection Hemp Fiber Reinforced Thermosetting Resins Electronic Packaging Material

In natural plant fibers，ramie is a rich natural fiber, which has no pollution to theenvironment. The study at home and abroad found composite materials made byhermosetting resin which is mixed with ramie fiber and particles, have small density,goodelectrical insulation performance,excellent dielectric performance and cheap rawmaterials no pollution to the environment.These are necessary to the electronic packagingmaterials.Based on the idea of utilizing renewable resource to develop new environmentalmaterials, chemical co-precipitation method was used to prepare the nanoparticles ofstannichydroxide and aluminium hydroxide in this paper, while ramie was disposed withdifferent processing methods. Ramie fabric/epoxy resin composites，raw ramie/epoxyresin composites, ramie fabric/unsaturated polyester composites and rawramie/unsaturated polyester composites were made by compression moulding forming.Moreover, their molding process and the optimum process parameters wereconfirmed.The content of stannichydroxide and aluminium hydroxide on properties ofcomposites were investigated through these analytical methods of DSC,infraredspectrum,UV spectrum,TG,SEM,TEM,mechanical performance determination and soon.The main conclusions are as follows:（1）The fracture mode of composite material was brittle fracture, and the fracturesurface was smooth. With the increase of the content of nanometer powder, the tensilestrength of the composite decreased after first increase. Ramie fabric/thermosetting resincomposite material had higher tensile strength, the maximum tensile strength is84.32MPa.（2）The thermal gravimetry of composite material had three stages: The first stagefrom room temperature to290℃, dehydration happened,and its weightloss ratio was lessthan3%.the second stage is from300℃to500℃, the pyrolysis of hydroxide and ramiehappened,its weightloss ratio was about80%.From500℃to1200℃is furthercarbonization stage,its weightloss ratio was about10%.So usage temperature ofcomposite materials should below300℃. （3）The dielectric properties of composite materials was related to the content,propotion, specific surface area of nanoparticle.The dielectric constant and dielectric lossof composite materials rised with the increase of the content of single powder content.When joined two kinds of powder, the dielectric constant and dielectric loss of compositematerials reduced with the decrease of the proportion of Sn（OH）₄. When the proportion is1:2, the dielectric properties of composite materials was well,and the dielectric constantand dielectric loss was4.09and0.007.（4） The heat decomposed temperature of Al（OH）₃was lower than Sn（OH）₄,andAl（OH）₃could release more crystal water, absorb more heat, so had better flame retardantproperty.The flame resistance of raw ramie/epoxy resin composite materials properties isbest, burning level is at FH-1, which the content of Al（OH）₃is14%.（5） Coefficient of heat conductivity of composite materials doped with Al（OH）₃washigher than one of composite materials doped with Sn（OH）₄,and the thermal conductivityof composite material rised with the increase of the content of powder.