Sericin as compatibilizer in starch/ polyester blown films

Abstract

ObstractThis study investigated the effects of low concentrations of sericin (≤ 1.5 wt%) in starch-poly(butylene-adipate-co-terephthalate) (PBAT) films. The films were produced by blown extrusion and mechanical, barrier and structural properties were determined. Films containing 1.0 and 1.5 wt% sericin showed higher tensile strength (6.41 and 6.59 MPa) and Young's modulus (90.88 and 132.71 MPa) compared with film without sericin (4.76 MPa and 18.64 MPa). When 0.5 wt% of sericin was used, the elongation was reduced by 62%. The addition of sericin in a concentration of 1.5% (w/w) decreased the water vapor permeability of films from 7.55 to 5.94 g (m s Pa) -1 , likely due to the formation of a more homogeneous and compact matrix. Based on these results, a mechanism of action is proposed, whereby sericin acts at the interface of the polymers (starch and PBAT), reducing the interfacial tension and enhancing compatibility.

Lipase immobilization on biodegradable film with sericin

“…Garcia et al 16 . observed the characteristic bands of random coil structure of SS at approximately 1650 cm –1 (C=O stretching, amide I) and 1520 cm –1 (N‐H deformation, amide II), present also in CS–PVA–SS film in this study.…”

“…Garcia et al 16 observed the characteristic bands of random coil structure of SS at approximately 1650 cm -1 (C=O stretching, amide I) and 1520 cm -1 (N-H deformation, amide II), present also in CS-PVA-SS film in this study. The bands at 1025, 1110, and 1270 cm -1 are assigned to stretching of C-O bonds present in starch, glycerol, PVA, and SS.…”

“…According to Garcia et al, 16 SS used in small concentration acts similar to a surfactant agent in polymeric blend. Thus, the side chains of amino acid residues with hydrophobic character (such as glycine) and hydrophilic F I G U R E 1 FTIR spectra CS-PVA-SS and CS-PVA films character (such as serine, aspartate and asparagine) interact with polymeric chains (starch and PVA), producing a more resistant and less flexible material.…”

“…Molecular weight of SS ranges from 24 to 400 kDa, 12 and serine (32.3%), 13 aspartic acid (16.71%), and glycine (13.49%) are the main amino acids 14,15 . If used as additive or adjuvant, SS can enrich the polymer blends and contribute to reducing environment damage 16 . Few studies report the use of supports containing SS in combination with starch and/or other biodegradables polymers for immobilizing enzymes 11,17,18 …”

“…14,15 If used as additive or adjuvant, SS can enrich the polymer blends and contribute to reducing environment damage. 16 Few studies report the use of supports containing SS in combination with starch and/or other biodegradables polymers for immobilizing enzymes. 11,17,18 Films containing cassava starch, PVA, and SS (CS-PVA-SS) were produced to immobilize Botryosphaeria ribis EC-01 lipases, using sandwich adsorption method.…”