The Research Of Characteristics Of Polypropylene Composites Reinforced With Ultrafine Bamboo-char

To improve the properties of polypropylene(PP)composites,bamboo particles(BP)and ultrafine bamboo-char(UFBC)were introduced to manufacture PP matrix composites.Different manufacture methods were carried out,and the effects of particle size and mass fraction of UFBC on the mechanical properties,moisture absorptions and thermal properties of PP/UFBC composites were investigated.The microstructure and properties of PP/UFBC and PP/BP/UFBC composites were tested,respectively.Effects of PP/BP/UFBC weight ratios on the characteristics of PP/BP/UFBC composites were explored.The interfacial bonding,strengthen and toughen mechanism were clarified.UFBC was introduced to reinforce the PP composites.Changes of UFBC loadings and manufacture methods on characteristics of PP/UFBC composites were investigated.The tensile strength of composites manufactured by injection molding reached highest value of 26 MPa when mass fraction of UFBC was 30%.Tensile module reached highest value of 450 MPa when 40%UFBC loading was used.When mass fraction of UFBC was 40%-50%,tensile strength of composites manufactured by hot press molding was great,while tensile module of composites manufactured by hot press molding reached 370 MPa when mass fraction of UFBC was 30%.Tensile properties and moisture resistance of composites manufactured by injection molding were better than those of composites manufactured by hot press molding.When mass fraction of UFBC was 20%,tensile strength of composites manufactured by injection molding improved 5 MPa than that of composites manufactured by injection molding.Injection molding was better to manufacture composites when UFBC content was no more than 30%,while hot press molding was better to manufacture composites when UFBC content was more than 30%.The addition of UFBC has no significant impact on the moisture absorption of composites.However,the crystallization temperature,melting temperature and fabricability of composites improved with the addition of UFBC.Different particle sizes of UFBC were introduced into the composites by twin-screw extrusion and injection moulding,both particles of UFBC has great improvement on the tensile properties.Crystallization temperature of composites reached the highest value of 120.5 ?,which increased by 10.4 ? than that of PP when 30%UFBC of particle 1(UFBC-P1)loading was used.With the increase of UFBC of particle 2(UFBC-P2)content,the tensile strength and tensile module increased,elongation at break decreased.When UFBC-P2 loading was 40%,tensile strength and tensile module of composites reached 33 MPa and 500 MPa respectively.UFBC-P2 has better reinforcement on mechanical properties,moisture resistance properties and thermal properties of composites than that of UFBC-P1.The addition of UFBC has no significant impact on moisture resistance properties of composites,moisture absorption of PP/UFBC composites was less than 0.1%,moisture resistance properties of composites was comparatively good.However,the addition of UFBC has remarkable reinforcement on crystallization temperature and melting temperature of composites.Uniform dispersion of UFBC in the PP matrix and good interaction via physical interfacial interlocks were observed with SEM.BP and UFBC were introduced into PP matrix composites as reinforcement.UFBC and BP had synergetic reinforcement on mechanical properties and thermal properties of composites through promoting the dispersion of reinforcement and form steady PP/BP/UFBC ternary system.When PP/BP/UFBC weight ratio was 70/25/5,tensile strength reached highest value of 30 MPa,which increased by 30%comparing to those of PP.When PP/BP/UFBC weight ratio was 70/20/10,tensile module reached highest value of 460 MPa;minimum density and moisture absorption of 0.96 g/cm3 and 0.05%were obtained;melting temperature reached the highest value of 166.6?,which increased by 5.9? than that of PP.Mechanical properties and thermal properties of PP/BP/UFBC composites were better than those of PP,PP/UFBC and PP/BP composites.Tensile module of PP/BP/UFBC composites increased by 35%,24%and 109%than that of PP/BP(70/30)composites,PP/UFBC(70/30)composites and PP.