Blends of poly(hydroxypropyl methacrylate) with 4-vinyl-co-N-vinyl-2-pyrrolidone
and with vinyltrimethylsilane-co-N-vinyl-2-pyrrolidone copolymers.
The effect of copolymer composition on interpolymer compatibility
Polimery 2001, No 11-12, 823
Glass transition temperatures (Figs. l, 3), DSC and TGA thermograms (Figs. 2, 4), and Fourier transform infrared (FTIR) spectra (Fig. 5) showed the binary blends (Table 1) of poly(2-hydroxypropyl methacrylate) (PHPMA) with 4-vinylpyridine-co-N-vinyl-2-pyrrolidone (4-VPy-co-VP) to be compatible over the whole range of compositions. The blends of PHPMA with vinyltrimethylsilane-co-N-vinyl-2-pyrrolidone (VTMS-co-VP) were found to be compatible up to VTMS contents of ~ 25 wt. %. The former blends (Figs. l, 2) are believed to be compatible on account of H-bonding of PHPMA's OH with the 4VPy and VP units of 4VPy-co-VP. In the latter blends, up to 25.7% of VTMS, H-bonds between PHPMA's OH groups and VP units suffice to provide compatibility, but at >25.7 wt. % VTMS, hydrophobic interactions of the VTMS moieties prevail and phase separation occurs.
Keywords: polymer-copolymer blends, interpolymer compatibility, phase separation, poly(2-hydroxypropyl methacrylate), 4-vinylpyridine-co-N-vinyl-2-pyrrolidone and vinyltrimethylsilane-co-N-vinyl-2-pyrrolidone copolymers