Chitosan–Starch–Keratin Composites: Improving Thermo-Mechanical and Degradation Properties Through Chemical Modification

Abstract

modified ground quill, 2522% for composites with modified long fiber and 3206% for the composites with modified short fiber. The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73% for chitosan-starch matrix up to 16% for the composites with 5 wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiating chitosan-starch films with sustainable features.

Additive manufacturing of green composites: Poly (lactic acid) reinforced with keratin materials obtained from Angora rabbit hair

“…Finally, NaOH treatment exhibits more invasive behavior toward the keratin material present in rabbit hair (predominantly α) 21 than that reported in chicken feathers (predominantly β) 22,23 under the same time and mercerization conditions. However, chemical treatment meets the objective, changing the surface topography needed to improve the link in the composites at the interface level with PLA, 22,24–27 unlike plasma treatments used in other investigations, 28 where no defects or tears were observed when comparing images obtained before and after treatment. Thus, current research is evaluating other properties, not considered in this article, investigating the implications of both treatments (NaOH at 1 and 5 h) and the repercussions of roughness produced by chemical treatment on the surface for other composite properties.…”

“…Therefore, this is considered a more aggressive procedure compared to helium (He) or He + air plasma treatment 17 but remarkably like ozone treatment, in which the outer layer of the fiber is also damaged 16 . Finally, NaOH treatment exhibits more invasive behavior toward the keratin material present in rabbit hair (predominantly α) 21 than that reported in chicken feathers (predominantly β) 22,23 under the same time and mercerization conditions. However, chemical treatment meets the objective, changing the surface topography needed to improve the link in the composites at the interface level with PLA, 22,24–27 unlike plasma treatments used in other investigations, 28 where no defects or tears were observed when comparing images obtained before and after treatment.…”

Starch Modified With Chitosan and Reinforced With Feather Keratin Materials Produced by Extrusion Process: An Alternative to Starch Polymers

“…Baker, and chicken feathers were donated by Pilgriḿs Company (Queretaro, Mexico). Chicken feathers were modified according to the methodology described by Flores‐Hernandez et al in 2017 . The reagent grade (>98%) sodium hydroxide (1310‐73‐2) was purchased from Sigma–Aldrich.…”

“…Thereafter, the fibers were dried at 35 °C for 48 h (fiber humidity = 9.2%) before making the composites. Chemical conditions to modify the keratin material were selected, taking into account the methodology described by Flores‐Hernandez et al in 2017 . The conditions described here showed changes on the surface, but the internal structure of the keratin was not impacted.…”

Application of Starch and Starch-Based Products in Food Industry

“…Chemical modification of starch usually involves acid or base at high concentration to destroy hydrogen bond intermolecular interactions and crystallization areas [137]. Hydroxyl group presence in starch may cause chemical reaction by exposing one or more reactive groups on its surface and will be efficiently coupled to matrix [138]. Modifying starch by using ether agents resulted in amphiphilic side chains of product and hydrophobic character of starch modified product was fixed by the length of alkenyl groups [139].…”