Thermoplastic Cellulose-Based Compound for Additive Manufacturing

The increasing environmental awareness is driving towards novel sustainable high-performance materials applicable for future manufacturing technologies like additive manufacturing (AM). Cellulose is abundantly available renewable and sustainable raw material. This work focused on studying the properties of thermoplastic cellulose-based composites and their properties using injection molding and 3D printing of granules. The aim was to maximize the cellulose content in composites. Different compounds were prepared using cellulose acetate propionate (CAP) and commercial cellulose acetate propionate with plasticizer (CP) as polymer matrices, microcellulose (mc) and novel cellulose-ester additives; cellulose octanoate (C8) and cellulose palmitate (C16). The performance of compounds was compared to a commercial poly(lactic acid)-based cellulose fiber containing composite. As a result, CP-based compounds had tensile and Charpy impact strength properties comparable to commercial reference, but lower modulus. CP-compounds showed glass transition temperature (Tg) over 58% and heat distortion temperature (HDT) 12% higher compared to reference. CAP with C16 had HDT 82.1 °C. All the compounds were 3D printable using granular printing, but CAP compounds had challenges with printed layer adhesion. This study shows the potential to tailor thermoplastic cellulose-based composite materials, although more research is needed before obtaining all-cellulose 3D printable composite material with high-performance.

Evaluation of the Properties of Cellulose Ester Films that Incorporate Essential Oils

Films made from cellulose esters are often used as bio-based food packaging materials. In this work, we studied the incorporation of nine essential oils into cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. The essential oils were derived from lime, nutmeg, eugenol, pimenta berry, rosemary, petitgrain, coffee, anise, and trans-cinnamaldehyde. In almost all cases, the addition of essential oils to cellulose ester reduced tensile strength and Young’s modulus but increased elongation at break. Thus, an essential oil acted like a plasticizer that enhanced the flexibility of the polymer. Essential oils containing limonene and pinenes (e.g., from lime and nutmeg) gave the strongest plasticizing action, whereas essentials oils containing fatty acids (e.g., from coffee) were the weakest plasticizers. The water barrier property was improved the most when essential oils were added to cellulose acetate; however, different cellulose ester/essential oil combinations showed different effects. Whereas most of the essential oils decreased the transparency of the films, eugenol, pimento berry, and anise were notable exceptions. Thus, depending on a specific application, a particular polymer/EO combination can be used to give the optimal performance.

Performance of cellulose acetate propionate in polycaprolactone and starch composites: biodegradation and water resistance properties

Introducing starch into some polymers such as polycaprolactone (PCL) has been used to produce biodegradable plastics. The existance of a derivative of cellulose such as cellulose acetate propionate (CAP) with starch and PCL combinations might affect the degradation rate of starch when only mixed with PCL. To check whether this was the case, different investigations such as enzymatic degradation, composting trial and water resistance performance over a wide range of different compositions of such composites were studied. It is deducible that the use of cellulose acetate propionate can improve the performance of such composites without a big significantly changing their whole biodegradability. It was found that the presence of cellulose acetate propionate improved the water resistance properties which enable such composites to be used in the packaging industry.