PVC膜专用料力学性能影响因素的探究

采用转矩流变仪、扫描电子显微镜、差示扫描量热仪和傅立叶变换红外光谱仪研究了聚氯乙烯(PVC)在不同加工温度和转速下的流变性能、塑化行为和结晶性能,探究了塑化效果、微纳层叠器数量对PVC力学性能的影响和PVC专用料吹塑成膜后的力学性能。结果表明,随着加工温度升高、转速增加,塑化时间缩短、凝胶化度增加,塑化行为进行越充分,而平衡扭矩随着加工温度升高而减小,随转速提高而增大;PVC结晶度随加工温度提高而增大,随转速增加而下降。在加工温度为185℃下,随着转速的提高,试样的断裂伸长率不断增大,而纵向、横向拉伸强度先增大后减小,且在转速为40 r/min时均达到最大值,分别为24.8 MPa和23.3 MPa,;在转速为40 r/min下,随着加工温度的提高,试样的断裂伸长率不断增大,而纵向、横向拉伸强度均先增大后减小,且在加工温度为185℃时均达到最大值,分别为24.6 MPa和22.6 MPa。PVC片材的密度和纵向拉伸强度与微纳层叠器数量成正比;与未加微纳层叠器相比,经过6节微纳层叠器后吹塑成膜的轴向拉伸强度提高13.5%,轴向断裂伸长率提高12.4%,轴向直角撕裂强度相应提高34.7%。

Study on Factors Affecting Mechanical Properties of PVC Film Special Materials

Rheological properties,plasticizing behaviors and crystal properties of polyvinyl chloride (PVC) at different pro-cessing temperatures and rotational speeds were studied by torque rheometer,SEM,DSC and FTIR to explore the impacts of plas-ticizing effects and numbers of laminated device on the mechanical properties of PVC and mechanical properties of PVC special material after blow molding. The results show :With the processing temperatures and rotational speed increasing,the plasticizing time is shorted,gelation degree is increased and plasticizing behavior is developed more fully,the balance torque decreases with the processing temperature increases but the balance torque increases with the rotational increases. The crystallinity of PVC increases with the processing temperature increasing and decreases with the rotational speed increasing in the process of mixing. When pro-cessing temperature is fixed (185℃ ),the elongation at break increases continuously,but the longitudinal and transverse tensile str-ength increase at first and then decrease with the increase of rotational speed,and the maximum values are 40 r/min,respectively 24.8 MPa and 23.3 MPa. When rotational speed is fixed (40 r/min),with the increase of processing temperature,the elongation at break increases continuously,but the longitudinal and transverse tensile strength increase first and then decrease,and the maximum values are 185℃,respectively 24.6 MPa and 22.6 MPa. The density and longitudinal tensile strength of PVC sheet are in propor-tion with the number of micro-nano laminated devices,comparing with blown films without micro-nano laminated device,the axial tensile strength increases by 13.5%,the axial elongation at break increases by 12.4%,and the axial right-angled tearing strength in-creases by 34.7% after adding 6 micro-nano laminated devices.