Synthesis of compatible blends of k-carrageenan with poly (4-vinylpyridine-CO-vinyl acetate) and poly (4-vinylpyridine-CO-methacrylonitrile)

• Main Author: Balgua, Charo Tolentino
• Format: text
• Language: English
• Published: Animo Repository 2005
• Subjects: Vinyl acetate; Methacrylonitrile; Supramolecular chemistry; Macromolecules; Chemical reactions; Reactivity (Chemistry); Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3342; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/10180/viewcontent/CDTG003997_P.pdf
• Institution: De La Salle University

Kappa-carrageenan, a natural macromolecular carbohydrate material from renewable resources, is widely used in many applications. In this study, blends of - Carrageenan (Carr) with poly(4-vinylpyridine-co-vinyl acetate) (P4VPy-VAc) and poly(4-vinylpyridine-co-methacrylonitrile) (P4VPy-MAN) were prepared by allowing both components to interact by acid-base interaction in DMF solution. Carr is a linear polysaccharide with sulfate moieties and under acidic condition, it can act as a proton donor due to the accessibility of the hydrogen in the sulfate group. The nitrogen in the pyridine group of P4VPyVAc or PrVPyMAN acts as the proton acceptor. The blends showed good compatibility -carr and copolymers of poly(4- vinylpyridine). Surface morphology, thermal, and thermomechanical properties of the blends were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), differential thermal analysis (DTA), and thermomechanical analysis (TMA). Results of the thermal shrinkage tests indicate that blends containing higher - Carr and lower 4VPy content exhibit maximum shrinkage at higher temperatures but lower shrinkage stress. Blends of -Carr/P4VPy-VAc exhibit higher shrinkage stress compared with -Carr/P4VPy-MAN. Evaluation of copolymer compositions of 4-vinylpyridine/vinyl acetate and 4- vinylpyridine/methacrylonitrile co-monomers show that copolymer prepared at varying feed ratios was found to be rich in 4VPy indicating that self-propagation of 4VPy predominates over cross-propagation with MAN and VAc respectively.