Thermoplastic cellulose acetate and cellulose acetate compounds prepared by reactive processing

Abstract

Novel families of thermoplastic polysaccharides such as cellulose-2,5-acetate were produced by means of reactive processing technology that grafted cyclic lactones simultaneously onto polysaccharide, hydroxyfunctional plasticizer, and optionally also onto hydroxyfunctional fillers. Organosolv lignin, cellulose, starch, and chitin were added to effect reinforcement of the polymer matrix. Mechanical and thermal properties depended upon molecular architecture of the components and process parameters such as temperature, feed ratios, and screw speed. Such blends and composites utilize renewable resources and are of interest in waste disposal via biodegradation.

Conformational analysis of xylan chains

“…Lauroyl-derived xylan films revealed a rather poor extension at break (10.5%) but a relatively high tensile strength (7.1 MPa); both parameters, which express the film stretching ability and the resistance to traction, respectively, are in accordance with some values observed with other plastified carbohydrate biopolymers. [5][6][7] The elastic modulus E (332 MPa) which measures the intrinsic stiffness of the plastic film was close to those of commercial products, such as polyethylene film. In addition, the thermomechanical properties of the dodecyl-grafted xylan film revealed a glass transition temperature (T g ) of 133°C, which is lower than that of the parent polymer (T g = 180°C), 8 the lowering of T g of xylan ester is due to both a decrease in polymer-polymer interactions and to an increase in free volume as fatty chains are introduced.…”

Influence of Lignin Type on the Mechanical Properties of Lignin Based Compounds

“…With a lignin content of only 13 wt.-% they have reached a 170% higher tensile strength and a 35% higher stiffness compared to the unfilled compound. [12] Feldman et al have investigated poly(vinyl chloride) compounds containing different types of lignin. [13,14] They have observed a 10% increase of yield stress with 7 wt.-% Alcell TM lignin without sacrificing the strain of the material.…”

Study of Reactive Melt Processing Behavior of Externally Plasticized Cellulose Acetate in Presence of Isocyanate

“…Often, external plasticizers were added to improve processing and homogenization and to facilitate the grafting reaction in the molten state due to better access to the functional groups. Nevertheless, in most cases long reaction times and large quantities of catalysts and monomers are necessary for sufficiently high grafting yields [17,18,19,20,21,22]. Thus, most of the processing conditions used in these studies are not viable for typical compounding processes prohibiting economic feasibility of the processes.…”