Manipulation of the Glass Transition Properties of a High-Solid System Made of Acrylic Acid-N,N'-Methylenebisacrylamide Copolymer Grafted on Hydroxypropyl Methyl Cellulose

• Published in: International journal of molecular sciences 2021-03, Vol.22 (5), p.2682
• Main Authors: Nassar, Nazim, Whitehead, Felicity, Istivan, Taghrid, Shanks, Robert, Kasapis, Stefan
• Format: Article
• Language: English
• Subjects: Acids; Acrylamides - chemistry; Acrylates - chemistry; Acrylic acid; Bioactive compounds; Calorimetry, Differential Scanning; Cellulose; Composition; Copolymerization; Copolymers; Crosslinking; Differential scanning calorimetry; Drug delivery systems; Fourier analysis; Free radical polymerization; Free radicals; Glass; Glass transition temperature; Graft copolymers; Heat measurement; High temperature; Hydroxypropyl methyl cellulose; Hypromellose Derivatives - chemistry; Infrared spectroscopy; Macromolecules; Materials Testing; Methylene bisacrylamide; Microscopy; Microscopy, Electron, Scanning; Morphology; N,N′-methylenebisacrylamide; Peptides; Pharmaceuticals; Phase transitions; Polymerization; Polymers; Potassium persulfate; Ratios; Rheological properties; Scanning electron microscopy; Spectroscopy, Fourier Transform Infrared; Spectrum analysis; Temperature effects; Thermogravimetric analysis; Thermogravimetry; Viscoelasticity; Vitrification; X-Ray Diffraction
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22052682

Crosslinking of hydroxypropyl methyl cellulose (HPMC) and acrylic acid (AAc) was carried out at various compositions to develop a high-solid matrix with variable glass transition properties. The matrix was synthesized by the copolymerisation of two monomers, AAc and N,N'-methylenebisacrylamide (MBA) and their grafting onto HMPC. Potassium persulfate (K S O ) was used to initiate the free radical polymerization reaction and tetramethylethylenediamine (TEMED) to accelerate radical polymerisation. Structural properties of the network were investigated with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), modulated differential scanning calorimetry (MDSC), small-deformation dynamic oscillation in-shear, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results show the formation of a cohesive macromolecular entity that is highly amorphous. There is a considerable manipulation of the rheological and calorimetric glass transition temperatures as a function of the amount of added acrylic acid, which is followed upon heating by an extensive rubbery plateau. Complementary TGA work demonstrates that the initial composition of all the HPMC-AAc networks is maintained up to 200 °C, an outcome that bodes well for applications of targeted bioactive compound delivery.