纳米SiO_(2)@TiO_(2)增强竹塑复合材料制备及托盘应用性能仿真分析

Preparation of nano-SiO_(2)@TiO_(2) reinforced bamboo-plastic composites and simulation analysis of performance for pallet application

随着生物质复合材料性能研究的不断深入,其在农业工程中的应用也逐渐广泛。该研究旨在提升竹塑复合材料(bamboo-plastic composites,BPC)力学性能和耐老化性,以实现其托盘制品的环保和应用性。首先,该研究采用三种不同配比竹粉(bamboo fiber,BF)与高密度聚乙烯(high density polyethylene,HDPE)制备BPC,并进行力学性能测试确定BF与HDPE最优配比。通过SiO_(2)包覆TiO_(2)粒子(SiO_(2)@TiO_(2)),硅烷偶联剂KH550改性SiO_(2)@TiO_(2)制备KH550-ST,采用喷涂法用KH550-ST改性BPC55制备纳米增强竹塑复合材料(KH550-ST-BPC),并进行力学性能和耐光老化性能分析。运用ANSYS Workbench软件对改性前后的BPC一体式托盘进行有限元仿真分析,理论验证纳米改性BPC托盘的应用性能。结果表明,随着BF含量的增加,BPC的抗拉性能和抗弯性能均有所提高。在BF与HDPE质量比为5:5时(BPC55),BPC力学性能最优。相比于BPC55,KH550-ST-BPC55弯曲强度和弯曲模量分别提升了31.11%和52.27%,拉伸强度和拉伸模量分别提升11.86%和21.92%,KH550-ST-BPC55的耐光老化性能提升77.79%。通过有限元仿真,发现KH550-ST-BPC55制BPC托盘在额定荷载下堆码仿真产生的最大变形量降低27.36%,极限荷载下降低23.41%,即可有效的堆码工况下的承载能力。该研究可为纳米SiO_(2)@TiO_(2)增强竹塑复合材料做物流周转单元的应用提供参考。

Biomass composites are ever-increasing in agricultural engineering.This study aims to enhance the mechanical properties and aging resistance of bamboo-plastic composites(BPC),in order to realize the environmental friendliness and application of its pallet products.Firstly,three ratios of bamboo fiber(BF)and high-density polyethylene(HDPE)were used to prepare the BPC.Then mechanical property tests were conducted to determine the optimal ratio of BF to HDPE.Among them,nano-TiO_(2) was widely used to enhance the performance of plant fiber/thermoplastic polymer composites,due to its chemical inertness,anti-aging,anti-bacterial properties,and non-toxic nature.An organic-inorganic co-modification was also employed to enhance the BPC properties for strong compatibility with bamboo fiber and plastic matrix.Nano-SiO_(2) was coated onto nano-TiO_(2) to prepare SiO_(2)@TiO_(2) nanoparticles for the high dispersion and aging resistance of TiO_(2).Nano-SiO_(2)@TiO_(2) modified BPC(KH550-ST-BPC)was prepared using the silane coupling agent KH550 as a reinforcing agent by a spray coating.The properties were evaluated to compare the mechanical properties,SEM images,and UV aging properties of BPC before and after modification.In addition,ANSYS Workbench software was used to perform the finite element analysis of BPC integrated pallets before and after modification,in order to verify the application performance of reinforced BPC pallets.The results indicated:1)The bending and tensile properties of BPC shared an increasing trend with the increase of bamboo fiber content.The optimal mechanical properties of BPC were obtained at a 5:5 mass ratio of BF to HDPE,with a 38.34%increase in the bending strength and a 62.19%increase in the bending modulus,compared with the 3:7 ratio.The tensile strength and modulus increased by 14.95%and 101.18%,respectively.SEM images revealed that there was a smoother interface for BPC55,which was better consistent with the mechanical test.2)The bending and tensile strength of BPC were enhanced by 31.11%and 11.86%,respectively,in the modified nano KH550-SiO_(2)@TiO_(2),while the bending and tensile modulus were enhanced by 52.27%and 21.92%,respectively.The interfacial gaps of modified BPC were significantly reduced in the SEM images,indicating the strong bonding between the bamboo fibers and HDPE.The KH550-SiO_(2)@TiO_(2) was introduced to fill the interface gaps for the BPC compatibility,which was better consistent with the mechanical property test.3)The surface morphology revealed that KH550-SiO_(2)@TiO_(2) modified BPC maintained better color stability for the high resistance to UV aging.While the unmodified BPC showed significant color fading after 1200 h UV irradiation aging.Colorimetric analysis confirmed that the color stability of KH550-ST-BPC was significantly better during UV aging,with a color aberration change value 77.79%lower than before.4)Finite element analysis indicated that the modified BPC pallet exhibited the better-bending properties and load-bearing capacity,with a 27.36%reduction in the maximum deformation under the rated load and a 23.41%reduction under the ultimate load in stacking simulation.These research findings can provide a strong reference for the application of nano-SiO_(2)@TiO_(2) reinforced BPC as logistics turnover units.