Additive Effects on Phase Transition and Interactions in Poly(vinyl methyl ether) Solutions

• Main Authors: Larisa Starovoytova, Julie Šťastná, Adriana Šturcová, Rafal Konefal, Jiří Dybal, Nadiia Velychkivska, Marek Radecki, Lenka Hanyková
• Format: Article
• Language: English
• Published: MDPI AG 2015-12-01
• Series: Polymers
• Subjects: additives; LCST; poly(vinyl methyl ether); thermal properties
• Online Access: http://www.mdpi.com/2073-4360/7/12/1533

A comparative study of thermal response of poly(vinyl methyl ether) in the presence of different hydrophilic and hydrophobic additives was performed by Nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and optical microscopy. The effect of polymer concentration and additive content on the appearance and extent of the phase transition was determined. A detailed study of interaction mechanism in solutions with two hydrophobic additives showed differences in the way in which polymer globules are formed. For solutions containing t-butyl methyl ketone and t-butanol, measurements of 1H spin-spin relaxations showed the presence of water and additive molecules bound in PVME globular structures. These originally-bound molecules are then slowly released from the globular-like structures. Incorporation of molecules into the globules disrupts the cooperativity of the transition and affects the size of globular structures.