The Research Of Bamboo Charcoal Enhances Physical-mechanical And Protective Properties Of Bamboo Plastic Composites

Bamboo plastic composite(BPC)is a basic material which is recyclable,extensive,products variety and shapes varied.Although it has many advantages,it also exists defects such as low mechanical properties and dimensional stability,easily aging and rotting since it always be used outdoors.In order to improve those properties,the use of bamboo charcoal(BC)was investigated as a filler into bamboo-plastic composites to achieve the improvement of physical-mechanical properties,hydrothermal aging and resistance against biological decay.Bamboo fiber(BF)and low-density polyethylene(LDPE)were used to manufacture the composites.Results of this study were as following:(1)The research of bamboo charcoal improved the physical-mechanical properties of BPC.Bamboo charcoal(BC)filled the gaps within the bamboo-plastic composites(BPC).While the content below 8%,the water resistance increased.When the BC content was high,it aggregated and formed gaps,so the water resistance decreased.After the bamboo was carbonized,the hydrophilicity and number of polar groups decreased.The water contact angle increased with increasing BC content.While the content of the BC was invariant,the sizes of the BC affected the contact angle by affecting the surface structuralfeature and surface roughness of the BPCs.The low-density polyethylene(LDPE)permeated the BC through the pores,enhancing the BC and creating a strong connection with the BC.The BC filled the gaps within the BPC.Thus,the physical-mechanical properties increased.When the BC content was high,it aggregated and weakened the materials,so the physical-mechanical properties decreased.The size of BC only affected the impact strength of physical-mechanical properties because the larger BC particles could absorb more energy before the BPC fractured.With the increasing of water temperature,the mold-resistance of BPC increased.It's because the nutrients in bamboo lost.The optimum physical-mechanical properties of BPC were got while the content of BC between 8%-12%.So the content was 10%while investigated the influence of BC size.(2)The research of bamboo charcoal improved the hydrothermal aging properties of BPC.BPC and BPC-BC aged at four different water temperatures were tested in this study.The moisture penetration behavior was found to follow Fick's law.The higher the immersion temperature was,the larger the diffusion coefficient was.BC reduced the water absorption at all aging temperatures and reduced the diffusion coefficient at temperatures higher than 39?,since BPC-BC has a small linear thermal expansion coefficient.The density and flexural properties of the specimens were clearly reduced after aging and re-dried,and the decrease grew sharper as the hydrothermal aging temperature was increased because aging in water increased the gaps between the BF and LDPE.BC increased the flexural properties of BPC after hydrothermal aging,not only because of the strong interactions between the BC and the polymer but also because of the smaller thermal expansion coefficient of BPC-BC.The wear rates of the composites first increased and then decreased as the aging temperature was increased.Immersing in water making BF easier to dislodge from the matrix.However,a higher water temperature degraded the pectin layer and decreasing the wear rate.BC also reduced the wear rate at all tested temperatures because of its strong connection with the polymer and self-lubricating characteristics.(3)The research of bamboo charcoal improved the protective properties of BPC.The maximum value of bamboo charcoal absorb CuAz is made by high-temperature processing among the high-temperature,high-pressure and ultrasonic processing methods.The much bigger concentration of CuAz,the more easily bamboo charcoal absorbed.The results show that the maximum value of bamboo charcoal absorb CuAz is 59.9mg/g and can be gotten when the concentration of CuAz is 2.8%,the treatment temperature is 70? and the treatment time is 24h.Adding bamboo charcoal which absorbed CuAz into BPC could get good protective property to Aspergillus niger,Trichoderma viride,Trichoderma viride and Coriolus versicolor.Fixation ratio of bamboo charcoal absorbed CuAz is 6.41%better than directly added.It also could decrease the dissolution of CuAz and prolong the useful life.