Miscibility and Phase Behavior in Blends of Poly(vinyl butyral) and Poly(methyl methacrylate)

Abstract

The miscibility and phase behavior in blends ofpoly(vinyl butyral) (PVB) and atactic poly-(methyl methacrylate) (PMMA) were studied by dynamical mechanical thermal analysis (DMTA) and optical microscopy (OM). PVB is regarded as a random copolymer containing vinyl butyral (VB) and vinyl alcohol (VA) units. In this study the copolymer composition was varied over a wide range, and PMMA was varied with respect to molecular weight. DMTA measurements show two distinct Tg's for the blends of all PVBs with PMMAs of high molecular weights (M w = 1.2 x 10 5 and 1.5 x 10 4) , indicating completely immiscibility. However, OM observations show that the size of phase-separated domains of PVB blends with PMMA (Mw = 1.2 x 10 5) depends on copolymer composition and displays a minimum in the range 22-33 wt % VA content. For low molecula r weight PMMAs (M w = 2 x 10 3 to 5 x 10 3) , miscibility with UCST-type phase behavior was observed in certain blends, the miscibility range depending on the copolymer composition and the molecular weight of the PMMA. The segmental interaction parameters of XvA,MMA, XVB,MMA, and XvA,VB and their temperature dependence were determined from the study. The copolymer composition dependence of the averaged interaction parameter between PVB a nd PMMA, x 12, was then calculated and displayed a minimum around 30 wt % VA content. These find ing can all be interpreted in terms of a copolymer effect in which the unfavorable interaction between PVB and PMMA is minimized at a certain copolymer compositions due to the repulsive interaction between VA and VB units within the PVB chains.

Nanostructure formation in polymer thin films influenced by humidity

“…4(d) have a granular structure and exhibit typical heights of 30-40 nm. The observed surface phase separation is in agreement with the findings described by Chen et al 10 They observed that PVB is only miscible with low molecular weight PMMA (M w < 5000 g/mol). Since in Fig.…”

“…10 PVB has been largely used for safety glass lamination due to its high transparency and good adhesion to glass. Moreover, the blending of PVB with PMMA results in a material that -as compared to pure PMMA -has increased impact strength and a reduced brittleness.…”

“…PVB, a polymer synthesized by the reaction of poly (vinyl alcohol) (PVA) with butyraldehyde under acidic conditions, can be regarded as a kind of random copolymer of (hydrophobic) vinyl butyral and (polar and thus hydrophilic) vinyl alcohol units. 10 PVB has been largely used for safety glass lamination due to its high transparency and good adhesion to glass. Moreover, the blending of PVB with PMMA results in a material that -as compared to pure PMMA -has increased impact strength and a reduced brittleness.…”

Colorful Hydrophobic Poly(Vinyl Butyral)/Cationic Dye Fibrous Membranes via a Colored Solution Electrospinning Process

“…In addition, PVB has both hydrophobic and hydrophilic properties due to its chemical structure with both vinyl butyral group and vinyl hydroxyl group [33, 34]. However, former interests are mostly focused on the hydrophilicity of PVB and its nanocomposite materials [35, 36].…”

Viscoelastic properties and extrusion processability of poly(vinyl butyral)

“…Because PVB contains both hydrophilic and hydrophobic parts in the structure, it can be miscible/compatible with both hydrophilic and hydrophobic polymers. In fact, several researchers have reported on the miscibility and/or compatibility with various polymers such as polyamide, poly(ε‐caprolactone), poly(butylene terephthalate), polyurethane, poly(ethylene glycol), poly(vinyl chloride), poly(methyl methacrylate), cellulose acetate, and poly(3‐hydroxybutyrate) . In particular, advanced studies on the miscibility considering the effect of copolymerization, that is, strong unfavorable interaction between the commoner units, have provided the new concept for a material design of polymer blends …”