Preparation and Characterization of Super-Absorbing Gel Formulated from κ-Carrageenan–Potato Peel Starch Blended Polymers

κ-carrageenan is useful for its superior gelling, hydrogel, and thickening properties. The purpose of the study was to maximize the hydrogel properties and water-absorbing capacity of κ-carrageenan by blending it with starch from potato peels to be used as safe and biodegradable water-absorbent children’s toys. The prepared materials were analyzed using FTIR and Raman spectroscopy to analyze the functional groups. Results showed that there was a shift in the characteristic peaks of starch and κ-carrageenan, which indicated their proper reaction during blend formation. In addition, samples show a peak at 1220 cm−1 corresponding to the ester sulfate groups, and at 1670 cm−1 due to the carbonyl group contained in D-galactose. SEM micrographs showed the presence of rough surface topology after blending the two polymers, with the appearance of small pores. In addition, the presence of surface cracks indicates the biodegradability of the prepared membranes that would result after enzymatic treatment. These results are supported by surface roughness results that show the surface of the κ-carrageenan/starch membranes became rougher after enzymatic treatment. The hydrophilicity of the prepared membranes was evaluated from contact angle (CA) measurements and the swelling ratio. The swelling ratio of the prepared membranes increased gradually as the starch ratio increased, reaching 150%, while the water-uptake capacity increased from 48 ± 4% for plain κ-carrageenan to 150 ± 5% for 1:2 κ-carrageenan/starch blends. The amylase enzyme showed an effective ability to degrade both the plain κ-carrageenan and κ-carrageenan/starch membranes, and release glucose units for up to 236 and 563, respectively. According to these results, these blends could be effectively used in making safe and biodegradable molded toys with superior water-absorbing capabilities.

Advances and Trends in the Physicochemical Properties of Corn Starch Blends

Corn starch is one of the most widely used biopolymers in the world for various applications, due to its high production, renewable, low cost, non-toxic, biodegradable and provide great stereochemical diversity by presenting a complex structure with unique qualities that they depend on multiple factors to obtain special properties for a specific use and/or of interest. From the synthesis of the starch granule to its extraction for its subsequent use, it promotes innovative characteristics, presenting infinite functionalities applicable and/or as a substitute for synthetic polymers. However, some limitations of hydrophilicity, thermal and mechanical properties, rapid degradability and strong intra and intermolecular bonds of the polymer chains make their use difficult in the medium and long term. Enzymatic, chemical and physical methods continue to be used today, creating by-products such as polluting waste and which can be costly. Therefore, the polymeric modification of the starch granule is necessary to mitigate limitations and by-products, currently the use of starch blends is a promising trend to produce new and innovative desirable properties. This chapter describes the advances and trends in the physicochemical properties of corn starch blends Zea mays L. as a potential material, leader for its attractive properties and benefits that it has to offer, demonstrating that when combined with other starches from different botanical sources and/or molecular structure present unique and unequaled synergisms.

Improving Mechanical Properties of PLA/Starch Blends Using Masterbatch Containing Vegetable Oil Based Active Ingredients

The aim of this research was to increase the compatibility between PLA and starch with vegetable oil-based additives. Based on tensile results, it can be stated, that Charpy impact strength could be improved for 70/30 and 60/40 blends in both unconditioned and conditioned cases, regardless of vegetable oil, while no advantageous change in impact strength was obtained with PLA-g-MA. Considering sample with the highest starch concentration (50%), the flexural modulus was improved by using sunflower oil-based additive, Charpy impact strength and elongation at break was increased using rapeseed oil-based additive in both conditioned and unconditioned cases. SEM images confirmed the improvement of compatibility between components.

Rheological and Microstructural Properties of Oil-in-Water Emulsion Gels Containing Natural Plant Extracts Stabilized with Carboxymethyl Cellulose/Mango (Mangifera indica) Starch

Emulsion gels are an alternative to developing food products and adding bioactive compounds; however, different stabilizers have been employed considering natural ingredients. In this work, stabilization of emulsion gels with blends of carboxymethylcellulose and kernel mango starch was performed with the addition of mango peel extracts, evaluating their physical, rheological and microstructural properties. Phenolic extract from mango peels (yields = 11.35 ± 2.05% w/w), with 294.60 ± 0.03 mg GAE/100 g of extract and 436.77 ± 5.30 µMol Trolox/g of the extract, was obtained by ultrasound-assisted extraction (1:10 peel: Ethanol w/v, 200 W, 30 min), containing pyrogallol, melezitose, succinic acid, γ-tocopherol, campesterol, stigmasterol, lupeol, vitamin A and vitamin E. In addition, mango kernel starch (yields = 59.51 ± 1.35% w/w) with 27.28 ± 0.05% of amylose was obtained, being the by-product of mango (Mangifera indica var fachir) an alternative to producing natural food ingredients. After that, stable emulsions gels were prepared to stabilize with carboxy methylcellulose–kernel mango starch blends and mango peel extracts. These results provide an ingredient as an alternative to the development of gelled systems. They offer an alternative to elaborating a new multifunctional food system with bioactive properties with potential application as a fat replacement or delivery system in the food industry.

Essential oils as multifunctional additives in biodegradable linear low density polyethylene/starch blends

Purpose This study aims to develop a biodegradable linear low-density polyethylene (LLDPE)/starch blends with improved mechanical and flow characteristics and evaluate the probability of using essential oils such as Moringa oleifira and castor oils as green plasticizers and compatibilizers to avoid using harmful chemicals. Design/methodology/approach Corn starch was blended with LLDPE through the melt blending technique. The corn starch content was varied from 5 to 40 phr in LLDPE. To enhance poor mechanical characteristic of the LLDPE/starch, essential oils such as M. oleifira and castor oils were incorporated into the composites with different concentrations starting from 1 to 7 phr. The essential oils’ effect on mechanical, flow character, thermal stability and electrical properties of the LLDPE/starch was also investigated. The morphology of LLDPE/starch containing essential oils was also investigated by scanning electron microscope (SEM). Findings The results revealed that increasing the corn starch content had an adverse effect on mechanical and flow characteristics of the composites, whereas incorporation of essential oils had increased the flow and mechanical characteristics of the composites. Also, dielectric measurements revealed that permittivity and dielectric loss increased by increasing oil content. Moreover, the values of the blends containing castor oil are higher compared to that containing M. oleifira. The SEM micrographs illustrated that the presence of essential oils in LLDPE/starch enhanced the distribution and the homogeneity of the composites, and the particle size of starch granules became smaller in LLDPE matrix. Originality/value This study aims to introduce green plasticizer and compatibilizer to avoid using harmful chemicals in packaging industry.

Effect of Sago Starch Modifications on Polystyrene/Thermoplastic Starch Blends

The preparation of polystyrene/thermoplastic starch (PS/TPS) blends was divided into three stages. The first stage involved the preparation of TPS from sago starch. Then, for the second stage, PS was blended with TPS to produce a TPS/PS blend. The ratios of the TPS/PS blend were 20:80, 40:60, 60:40, and 80:20. The final stage was a modification of the composition of TPS/PS blends with succinic anhydride and ascorbic acid treatment. Both untreated and treated blends were characterized by their physical, thermal, and surface morphology properties. The obtained results indicate that modified blends have better tensile strength as the adhesion between TPS and PS was improved. This can be observed from SEM micrographs, as modified blends with succinic anhydride and ascorbic acid had smaller TPS dispersion in PS/TPS blends. The micrograph showed that there was no agglomeration and void formation in the TPS/PS blending process. Furthermore, modified blends show better thermal stability, as proved by thermogravimetric analysis. Water uptake into the TPS/PS blends also decreased after the modifications, and the structural analysis showed the formation of a new peak after the modification process.

End-of-Life Options for (Bio)degradable Polymers in the Circular Economy

End-of-life options for plastics include recycling and energy recovery (incineration). Taking into account the polymeric waste, recycling is the intentional action that is aimed at reducing the amount of waste deposited in landfills by industrial use of this waste to obtain raw materials and energy. The incineration of waste leads to recovery of the energy only. Recycling methods divide on mechanical (reuse of waste as a full-valuable raw material for further processing), chemical (feedstock recycling), and organic (composting and anaerobic digestion). The type of recycling is selected in terms of the polymeric material, origin of the waste, possible toxicity of the waste, and its flammability. The (bio)degradable polymers show the suitability for every recycling methods. But recycling method should be used in such a form that it is economically justified in a given case. Organic recycling in a circular economy is considered to be the most appropriate technology for the disposal of compostable waste. It is addressed for plastics capable for industrial composting such as cellulose films, starch blends, and polyesters. The biological treatment of organic waste leads also to a decrease of landfills and thereby reducing methane emissions from them. If we add to their biodegradability the absence of toxicity, we have a biotechnological product of great industrial interest. The paper presents the overview on end-of-life options useful for the (bio)degradable polymers. The principles of the circular economy and its today development were also discussed.

A Study of the Effect of Starch Content on the Water Absorption of PVA/starch Blends

The present work aims to study physical tests such as the water absorption tests of PVA; PVA/corn starch blends at different mass percent (25, 30, 35, 40, and 50%) of corn starch after immersion in distilled water for ten minutes. The blends were also characterized by FTIR analysis, and an optical microscope. Casting method used to prepare samples. The results of water absorption exhibited that the weight losses of the sample increases the starch content rises in the PVA matrix. Also, it was found the highest value of the swelling ratio % at (50% PVA /50% Starch) blend, while minimum values of the swelling ratio % at (75%PVA /25%Starch) blend and pure PVA film. It was observed from optical microscope that the starch granules disperse well at 25 and 30 wt.% of the starch in the blend films. Nevertheless, clustering could be observed in the polymer blend at 35, 40, and 50 wt.% of starch component. It was shown that porous and spherical voids after the samples were immersed in distilled water.