Abstract
AbstractPoly(vinyl chloride) polymers stabilized with tribasic lead sulfate discolor upon exposure to hydrogen sulfide gas as a result of lead sulfide formation. The discoloration occurs for samples in both cord and sheet forms and is shown to be a function of total H2S exposure, reaching a limiting value that is determined by the amount of lead stabilizer used in the polymer formulation. The permeation and diffusion constants for H2S through PVC stabilized with tribasic lead sulfate and with a liquid Ba–Cd–Zn formulation are found to be PPb = (6.0 ± 0.2) × 10−9, PBaCdZn = (5.2 ± 0.2) × 10−9 (both in cm3 gasċcm film/cm2 areaċsecċcm Hg), DPb = (1.3 ± 0.2) × 10−7 cm2/sec, and DBaCdZn = (6.4 ± 0.6) × 10−8 cm2/sec, all measured at 21°C. The stabilizing efficiencies of the formulations were assessed by HCl evolution measurements, which show that exposure to H2S decreases the initial polymer stability for both Pb‐stabilized and Ba–Ca–Zn‐stabilized formulations. Protection of stabilized PVC formulations from diffusing hydrogen sulfide is thus advisable for long‐term stability as well as for color integrity.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
