Synthesis and structure of poly(epsilon-caprolactone)/synthetic montmorillonite nano-intercalates

• Published in: European polymer journal 2004-11, Vol.40 (11), p.2591-2598
• Main Authors: Kiersnowski, Adam, Dabrowski, Pawel, Budde, Hednrik, Kressler, Jorg, Piglowski, Jacek
• Format: Article
• Language: English
• ISSN: 0014-3057
• DOI: 10.1016/j.eurpolymj.2004.0.014

Bulk polymerisations of E-caprolactone (CL) were conducted at 170 DGC in the presence of catalytic traces of water and 10, 30 and 50 wt% of hydrated synthetic montmorillonite SOMASIF ME100 (M) without additional catalysts. In both cases a low molecular poly(L-caprolactone) (PCL) was produced (Mw = 5360-22,432). As revealed by 1H NMR and GPC analyses the montmorillonite present in the system induced both significantly higher lactone hydrolysis and polymer chain growth rates. Wide-angle X-ray scattering (WAXS) technique was applied to investigate the changes in clay stratification after swelling with monomer and after the polymerisation. The scattering peaks from clay (001) periodicity recorded for the silicate in dispersions and in the composites are shifted towards lower angles, which indicate an intercalation of CL as well as PCL in the galleries. Narrow intensity distribution of Bragg peaks recorded for both CL/M mixtures and resulting nano-intercalates testifies that the well ordered, layered structure of montmorillonite is retained in the silicate swollen with E-caprolactone and after the polymerisation. The results suggest that PCL chains are flatly arranged onto each side of silicate platelet and they create pseudo-bilayers inside the silicate's gallery.