The objective of this study of modified polypropylene (PP) fibres using nanoadditives (nano-CaCO3 and Cloisite 30B) was to determine the influence of these additives on thermal and mechanical properties, but especiall...The objective of this study of modified polypropylene (PP) fibres using nanoadditives (nano-CaCO3 and Cloisite 30B) was to determine the influence of these additives on thermal and mechanical properties, but especially on the barrier properties of the nanocomposite fibres against UV radiation. The DSC data obtained from measurements of PP/CaCO3 or PP/C30B nanocomposite fibres were used for determination of the constants n and K of the Avrami equation and in the estimation of other thermal properties of the fibres, such as their crystallization half-time t1/2, rate of crystallization t1/2, the necessary time for maximum crystallization tmax and free energy per unit area of surface in the lamella perpen-dicular to the axis of a high-molecular chain se. The nano-CaCO3 or Closite 30B fillers (pre-treated separately in three different solvents: glycerine, acetone and water) did not influence the melting temperatures but caused an increase in PP crystallization temperatures in comparison with the pure PP fibres. The pre-treatments of nanoadditives resulted in increase of n, K, t1/2 values and decrease of t1/2, tmax as well as the values of free surface energies per unit area of the modified PP fibres. There was also observed a decrease in the mechanical properties, however, there was an increase of barrier properties against UV radiation of nanocomposite PP fibres in comparison with neat PP fibres, which was one of the main objectives of the study.展开更多
文摘The objective of this study of modified polypropylene (PP) fibres using nanoadditives (nano-CaCO3 and Cloisite 30B) was to determine the influence of these additives on thermal and mechanical properties, but especially on the barrier properties of the nanocomposite fibres against UV radiation. The DSC data obtained from measurements of PP/CaCO3 or PP/C30B nanocomposite fibres were used for determination of the constants n and K of the Avrami equation and in the estimation of other thermal properties of the fibres, such as their crystallization half-time t1/2, rate of crystallization t1/2, the necessary time for maximum crystallization tmax and free energy per unit area of surface in the lamella perpen-dicular to the axis of a high-molecular chain se. The nano-CaCO3 or Closite 30B fillers (pre-treated separately in three different solvents: glycerine, acetone and water) did not influence the melting temperatures but caused an increase in PP crystallization temperatures in comparison with the pure PP fibres. The pre-treatments of nanoadditives resulted in increase of n, K, t1/2 values and decrease of t1/2, tmax as well as the values of free surface energies per unit area of the modified PP fibres. There was also observed a decrease in the mechanical properties, however, there was an increase of barrier properties against UV radiation of nanocomposite PP fibres in comparison with neat PP fibres, which was one of the main objectives of the study.
