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

Abstract

Starch (potato), chitosan, and feather keratin are used for processing biodegradable films produced by extrusion. The morphology of the films is examined with a scanning electron microscope and showed the excellent dispersion of keratin. The dispersion is the result of compatibility between the polysaccharides and proteins, as well as the proper operation of the extrusion process. Water solubility of the starch-chitosan films decreased with an increase of keratin materials. The storage modulus increased up to 137% for the composites with unmodified ground quill, and by 192% for composites with modified ground quill. In a tensile test, the composites with unmodified and modified quill reached outstanding increments up to 8160 and 7250% in elastic modulus, respectively, compared to the matrix. They also reached up to 3800% and 3150% in maximum strength, respectively, compared to the matrix. The lysozyme test showed relevant changes in the degradability rate, because the weight loss of the films at 3 weeks decreased from 53% for starch-chitosan matrix and up to 34% for composites with 5 wt% of modified quill. The results corroborated that chicken feather materials can be useful for the development of a manufacturing process for starch composites, and the decomposition of starch-chitosan composites can be controlled depending on the content and type of keratin.

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

“…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.…”

“…This behavior can be ascribed to α‐keratin in rabbit hair, which is flexible and promotes lower rigidity in these composites 46,47 . Other polymer composites developed from materials with predominantly β‐ keratin, 21 obtained from chicken feathers, have a tendency to be more rigid compared to the natural polymer matrix processed by methods other than 3D printing 22,23,48 …”

Keratin Associations with Synthetic, Biosynthetic and Natural Polymers: An Extensive Review

“…Composites without feather (NaOH) treatment presented significant increases in storage (up to 137%), elastic modulus (up to 8160%) and maximum strength (up to 3800%), while composites with feather treatment presented increases up to 192% in storage modulus, 7250% in elastic modulus and 3150% in maximum strength. However, the increment of keratin in the composites decreased the degradability rate [276].…”

Environmentally Friendly Melt-Processed Chitosan/Starch Composites Modified with PVA and Lignin

“…More recently, chitosan has been plasticized during a one-step extrusion process [ 23 , 24 , 25 , 26 ]. The plasticizing system (glycerol with acetic acid) was mixed with polyethylene [ 21 ] or keratin fiber [ 25 ].…”

“…More recently, chitosan has been plasticized during a one-step extrusion process [ 23 , 24 , 25 , 26 ]. The plasticizing system (glycerol with acetic acid) was mixed with polyethylene [ 21 ] or keratin fiber [ 25 ]. Extrusion compounding was shown to be a promising method for the industrial processing of chitosan/starch composites due to the possibility of further molding of the materials and its high productivity.…”