In the quest for superior materials, the exploration of nanocomposites emerged in the early 1990s, spearheaded by Toyota scientists researching nylon 6. A breakthrough in achieving a high degree of dispersion of organoclay aggregates promised substantial enhancements in mechanical properties and the morphology of polymer matrices. This research has far-reaching implications, impacting heat distortion temperature and gas barrier properties in nanocomposites.
Key Challenges: Polymer-Clay Compatibility
To unlock the full potential of nanocomposites, addressing the compatibility between a polymer matrix and clay is crucial. Efforts spanning two decades have focused on surface modifications of natural clay using surfactants. However, there’s no one-size-fits-all surfactant. Achieving compatibility requires tweaking either the polymer matrix’s chemical structure or the surfactant’s structure on the nanoclay surface.
Innovative Solutions by Han et al.
Han et al. contributed significantly to this field by successfully preparing nanocomposites with a high degree of dispersion. They introduced functional groups into a polymer matrix, leading to the exfoliation of nanoclay aggregates, as confirmed by TEM and XRD. Specific interactions, including hydrogen bonding and ionic interactions, were revealed through FTIR spectroscopy, UV-vis spectroscopy, and solid-state NMR spectroscopy. Their findings laid the foundation for guidelines in achieving nanocomposites with optimal dispersion.
Starch-Based Nanocomposites: A Growing Frontier
The exploration of starch-based nanocomposites commenced several years ago, with numerous reports surfacing. However, XRD patterns and TEM images consistently displayed a low degree of nanoclay dispersion. This dissertation tackles this challenge by delving into nanocomposites based on chemically modified starch.
The Role of Modified Starch
Chemically modified starches, featured in the study, play a pivotal role in determining nanocomposite characteristics. The attachment of hexanoyl or benzoyl groups into starch molecules aims to lower the glass transition temperature and enhance hydrophobicity. Simultaneously, ionic groups, either acetate sodium or trimethylammonium chloride, are introduced, envisioning ionic interactions with layered silicates of clay.
Investigating Nanocomposite Characteristics
The dissertation unfolds by presenting chemical structures, thermal behavior, biodegradability, and hydrophobicity of modified starches. The subsequent chapter explores blend miscibility based on chemically modified starch and EVOH. A detailed examination of nanocomposite dispersion characteristics using XRD and TEM, coupled with investigations into ionic interactions through FTIR spectroscopy, forms the core of this groundbreaking study. Mechanical properties of the prepared nanocomposites are also scrutinized, offering valuable insights into the potential of starch-based nanocomposites.
In essence, this research paves the way for a deeper understanding of nanocomposites, offering a roadmap for creating materials with enhanced properties and opening doors to innovative applications in diverse industries.