How are the properties of biocomposite foams influenced by the substitution of cassava starch for its residual sources?

Energy and stochastic economic assessment for distributed power generation from Manipueira biogas

Cassava is a staple food in many countries, and this food source differs from other crops in that its processing generates a highly polluting and toxic residue (manipueira) that requires further treatment. The present study analyzed the economic feasibility of anaerobic digestion of manipueira for producing clean electricity through distributed generation (DG) while simultaneously eliminating toxic compounds. This eliminates the toxic residues. For this, an approach for the sizing of DG plants from manipueira biogas was presented, a non-trivial task which is not widespread in the literature. For two plants with different capacities, a deterministic economic analysis was carried out based on the criteria of Net Present Value, Internal Rate of Return, and Discounted Payback. Finally, the project risk was assessed through a sensitivity and stochastic analysis using Monte Carlo Simulation. The empirical verification was done on Brazilian data. When considering the NPV criterion, the results indicate a feasibility probability of 9.25% and 81.21% for scenarios 01 and 02, respectively. The results show that scale gains were important in reducing the impact of the investment and, at the same time, the larger scale of the project makes the cost of capital more relevant to the result. These findings show the need for subsidies for the investment, in addition to the promotion of specific credit lines that enable small-scale generation, or that can improve results in greater capacity.

The Use of New Waste-Based Plasticizer Made from Modified Used Palm Oil for Non-Glutinous Thermoplastic Starch Foam

A novel waste-based plasticizer derived from modified used palm oil (mUPO) was successfully developed and has been used as a new plasticizer to non-glutinous thermoplastic starch foam to improve their properties. The molecular weight and hydroxyl number of the mUPO was 3150 g/mol and 192.19 mgOH/g, respectively. The effects of mUPO content ranging from 0 to 9 phr were investigated. The results revealed that the optimal mUPO content as an additive was 6 wt%. The addition of mUPO had a direct effect on the mechanical properties and thermal properties. The impact strength increased from 1.30 to 4.55 J/m, while the glass transition temperature (T_g) decreased from 70.83 to 66.50 °C by increasing mUPO from 0 phr to 6 phr in the thermoplastic starch foam. The mUPO, on the other hand, has also the potential to reduce shrinkage from 33.91 to 21.77% and moisture absorption from 5.93 to 1.73% by increasing the content from 0 phr to 6 phr in starch foam. Furthermore, the mUPO helps the forming of the foam structure as measured by SEM, and the mUPO utilization of waste-based material could be a promising green alternative plasticizer for starch components, especially starch foam applications.

Biobased composites from agro-industrial wastes and by-products

The greater awareness of non-renewable natural resources preservation needs has led to the development of more ecological high-performance polymeric materials with new functionalities. In this regard, biobased composites are considered interesting options, especially those obtained from agro-industrial wastes and by-products. These are low-cost raw materials derived from renewable sources, which are mostly biodegradable and would otherwise typically be discarded. In this review, recent and innovative academic studies on composites obtained from biopolymers, natural fillers and active agents, as well as green-synthesized nanoparticles are presented. An in-depth discussion of biobased composites structures, properties, manufacture, and life-cycle assessment (LCA) is provided along with a wide up-to-date overview of the most recent works in the field with appropriate references. Potential uses of biobased composites from agri-food residues such as active and intelligent food packaging, agricultural inputs, tissue engineering, among others are described, considering that the specific characteristics of these materials should match the proposed application.

Corn starch reactive blending with latex from natural rubber using Na+ ions augmented carboxymethyl cellulose as a crosslinking agent

A mixture of corn starch and glycerol plasticizer (CSG) was blended with latex natural rubber (LNR) and carboxymethyl cellulose (CMC). The addition of 10 phr of CMC improved the Young's modulus (6.7 MPa), tensile strength (8 MPa), and elongation at break (80%) of the CSG/LNR blend. The morphology of the CSG/LNR/CMC blends showed a uniform distribution of LNR particles (1-3 µm) in the CSG matrix. The addition of CMC enhanced the swelling ability and water droplet contact angle of the blends owing to the swelling properties, interfacial crosslinking, and amphiphilic structure of CMC. Fourier transform infrared spectroscopy confirmed the reaction between the C=C bond of LNR and the carboxyl groups (-COO-) of CMC, in which the Na+ ions in CMC acted as a catalyst. Notably, the mechanical properties of the CSG/LNR/CMC blend were improved owing to the miscibility of CSG/CMC and the CMC/LNR interfacial reaction. The CSG/LNR/CMC biodegradable polymer with high mechanical properties and interfacial tension can be used for packaging, agriculture, and medical applications.