Study of the miscibility of poly(styrene-co-4-vinylbenzoic acid) with poly(ethyl methacrylate) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] by inverse gas chromatography.
Poly(styrene) is immiscible with poly(ethyl methacrylate). The introduction of a small amount of 4-vinylbenzoic acid units along poly(styrene) chains (PS-VBA) enhanced its miscibility with poly(ethyl methacrylate) (PEMA) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] (PEMA-DAE), as observed from the appearance of a single composition dependent glass transition temperature for each binary system using inverse gas chromatography. The negative values of the apparent polymer-polymer interaction parameter, chi(23)app, determined with different families of molecular probes, for three blend compositions and over a range of temperature confirm quantitatively the miscibility of these blends. The chi(23)app values for PEMA(PS-VBA) and (PEMA-DAE)-(PS-VBA) blends are dependent of the chemical nature of the probes, the temperature and the blend composition.
Fourier Transform Infrared Spectroscopy Study on Effects of Temperature on Hydrogen Bonding in Amine-Containing Polyurethanes and Poly(urethane−urea)s
Three types of amine-containing polyurethanes and poly(urethane−ureas), N-methyldiethanolamine (MDEA) and/or tetraethylenepentamine (TEPA) as the chain extender and poly(ethylene glycol) of MW 400 as the soft-segment component, have been studied by FTIR. The hydrogen bonding in hard and soft segments was examined for the extent of phase separation, and the microstructure was evidenced by differential scanning calorimetry (DSC). The temperature effects on the hydrogen bonding were also investigated. They show a significant amount of hydrogen bonding between the hard and soft segments. It indicates that there exists a large amount of partial phase mixing of hard and soft segments compared to the conventional polyurethanes. The bulky CH3 groups of MDEA in hard segments restrict the hydrogen bonding within the hard segments, while the TEPA-containing urethane−urea polymers have more distinct phase separation. However, all of the polymers studied are amorphous materials such that the dissolved soft segments in...
Blends and complexes of poly(monomethyl itaconate) with polybases poly(N,N-dimethylacrylamide) and poly(ethyloxazoline). Association and thermal behavior
This paper reports on the interpolymer complex formation and polymer blends between poly(monomethyl itaconate) (PMMI) and two polymer acceptors poly(N,N-dimethylacrylamide) (PDMA) and poly(ethyloxazoline) (PEOX). We have found that the formation or inhibition of interpolymer complexes for these systems strongly depends upon the solvent medium. The stoichiometry of the complexes prepared from methanol solutions has been calculated from elemental analysis, resulting in a stoichiometry near a 1:1 ratio. Specific interactions of PMMI/PDMA and PMMI/PEOX complexes and blends have been characterized by FTIR. Strong hydrogen bonding for complexes and blends has been found. Finally, a calorimetric and thermogravimetric study of the complexes and blends has been performed in a wide temperature range.