Effects of Moisture Content, CEC, and Processing Conditions on Mechanical Properties and Long-Term Reliability of PBT Fiber-optic Buffer Tubes

摘要

Poly-butyleneterephthalate (PBT) Fiber optic buffer tubes were manufactured while varying initial material Carboxyl Endgroup Concentrtion (CEC), initial moisture content, as well as extrusion linespeed and cooling profile. Mechanical tests on aged and unaged tubes were correlated to the state of material degradation through capillary rheometer experiments and Melt Flow Index (MFI) measurements. Incomplete dryign and use of PBT with a high initial CEC are shown to lead to more rapid reduction of molecular weight during extrusion as well as poorer long-term hydrolytic stability. By proper selection of material and processing conditions, material lifetimes can be at least doubled.