On Structural and Molecular Order in Cellulose Acetate Butyrate Films

Abstract

Cellulose acetate butyrate (CAB) is a possible candidate, being a raw material derived from renewable resources, to replace fossil-based materials. This is due to its thermoplastic properties and the relative ease with which it could be implemented within the existing industry. With a significant amount of variation in CAB on the market today, a knowledge gap has been identified regarding the understanding of the polymer structural arrangement in films. This relates to the underlying mechanisms that regulate CAB film material properties, insights that are important in product development. In this study, commercially available CAB was investigated with XRD, SEM, AFM, and TOPEM DSC in order to obtain physicochemical information related to its micro-structural features in solvent-cast films. The film-forming ability relates mostly to the number of hydroxyl groups, and the semi-crystallinity of the films depends on the type and position of the side groups along the cellulose backbone. The appearance of signs of possible cholesteric ordering in the films could be connected to higher amounts of hydroxyl groups along the backbone that disturb the helix arrangement, while the overall order was primarily related to the butyrate substitution and secondarily related to the molecular weight of the particular CAB studied. Cold crystallization was also observed in one CAB sample.

Photopolymerization Pattern of New Methacrylate Cellulose Acetate Derivatives

“…The crystallinity modification of various compounds can be easily evaluated by investigating the nature of Bragg’s peaks from the XRD patterns. It is a well-known issue that thermal history has a substantial impact on the crystallization processes of different types of materials, and cellulose derivatives are no exception [ 38 , 39 , 40 ]. The frequently used method to achieve samples with a similar thermal background is thermal annealing; however, this technique is not suitable in the case of our samples substituted with various amounts of double bonds that are susceptible to thermal polymerization [ 41 ].…”