Polymer melting temperatures and crystallinity at different pressure applied

摘要

The present work aims at the experimental investigation of the effect of an increased thermal bonding pressure on the melting point (the so-called Clapeyron effect) of three polymers employed in nonwovens. Namely, this work quantifies the dependence of melting temperature on pressure in these polymers. The following three polymers were used in the present experiments: polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and polypropylene (PP) (all three already received in the form of nonwovens). A simple novel method of measurements of melting points of such polymers under different pressures was proposed and developed. The results revealed: (i) the melting point of PBT nonwovens increased by about 12 degrees C when the applied pressure was increased up to 277.79 atm; (ii) the melting point of the PET nonwovens increased by about 7 degrees C when the applied pressure increased up to 104.86 atm; (iii) the melting point of PP nonwovens increased by about 6 degrees C when the applied pressure was increased up to 104.86 atm. The melting temperature measurements by the present method were also validated through differential scanning calorimetry measurements with the above-mentioned three polymers without applied pressure.