Monitoring the evolution of the microstructure of vinyl silane monomer containing poly(vinyl acetate) based copolymer latexes during storage

• Published in: European polymer journal Vol. 121; p. 109299
• Main Authors: Barquero, Aitor, Agirre, Amaia, Barandiaran, María Jesús, Leiza, Jose Ramon
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2019; Elsevier BV
• Subjects: Copolymers; Crosslinking; Drying; Drying agents; Emulsion polymerisation; Emulsion polymerization; Evolution; Fractionation; Gyration; Latex; Latex microstructure; Light scattering; Mass distribution; Mechanical properties; Microstructure; Monomers; Poly(vinyl acetate); Refractivity; Shelf stability; Studies; Vinyl acetate; Vinyl trialkoxysilane; Vinyl trialkoxysilane; Emulsion polymerisation; Shelf stability; Poly(vinyl acetate); Latex microstructure
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2019.109299

[Display omitted] •Vinyl silane modified latexes can only evolve when stored in the latex state.•Samples stored in the dry state do not evolve.•The crosslinking density within the latex particles increases during their storage.•The hydrolysis rate of the vinyl silane determines the evolution rate of the latex.•Interparticle interactions do not have a significant impact at 23 °C. The evolution of the microstructure of three silane modified latexes during the storage is studied. The gel content was periodically measured before and after the drying of the latex by centrifugation and soxhlet extraction respectively, and the molar mass distribution and average radius of gyration of the crosslinked chains were measured by Asymmetric Flow Field Flow Fractionation/Multi Angle Light Scattering/Refractive Index (AF4/MALS/RI). It was observed that after drying, the microstructure of the latex did not change over time, while when it was stored in the dispersed state the gel content and average molar mass increased and the swelling degree (derived from the average radius of gyration) decreased, as an indication of crosslinking reactions happening. The rate at which the microstructure evolved correlates well with the hydrolysis rate of the different vinyl silane monomers.