Characterization of extruded film based on thermoplastic potato flour

Potato flour is abundant and less expensive than starch, though its major component is starch. It would therefore seem to be an attractive and viable source of biomass for biodegradable thermoplastic products. This study prepared thermoplastic potato flour (TPF) and thermoplastic potato starch (TPS) films by extrusion and investigated their properties. A mixture of glycerol and triethyl citrate (25−35% of total weight) was chosen for the plasticizer. Properties of the TPF film, such as mechanical properties, surface hydrophilicity, surface energy, moisture sorption isotherm, and glass transition temperature (T_g), were characterized and compared with TPS film. The results showed that TPF film was comparable to TPS film in many properties. The mechanical properties of the TPF film, including tensile strength, elongation at break, and tensile modulus, were similar in magnitude to TPS film. In addition, TPF film showed lower T_g and surface hydrophilicity, but higher surface wetting capacity than TPS film. Components other than starch in potato flour were believed to have had a plasticization effect on TPF properties. Overall, potato flour demonstrated a comparable capacity for manufacturing thermoplastic film similar to the more expensive starch feedstock. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Investigation of the Effects of Microwave Treatment on the Optical Properties of Apple Slices During Drying

The objective of this work was to study the changes of optical properties of apple (Golden Delicious) slices during drying. The optical parameters compared on the basis of Hunter values (L, a, b) changes as well as total color difference (Δ E) and browning index (BI). The effect of coating materials including carboxymethylcellulose (CMC), starch, and pectin as well as microwave treatment on optical properties and microstructure of dried samples were investigated. To analyze the effects of these processes on microstructure, scanning electron microscopy (SEM) was employed. Results showed that optical properties as well as microstructure of apple were affected by coating material and drying condition. Coated samples by CMC had a lower L and higher BI, but different results in the presence of starch were obtained. Microwave treatment in the presence of appropriate coating materials could improve the optical properties of dried apple slices.     

Influence of processing on the mechanical properties and morphology of starch-based blends for film applications

This article describes the effect of processing on the properties and morphology of thermoplastic starch (TPS) and poly(butylene adipate-co-terephthalate) (PBAT) blends and films with high starch content. Different process parameters were modified during compounding of blends and extrusion of blown films. Morphology was examined through scanning electron microscopy. Mechanical and optical characterization of films was carried out as well. Decreasing specific throughput during compounding led to an increase in strain at break of the blends from 66 to 497%. The tensile strength increased from 6 to 22 MPa as well. The highest elastic modulus and tear resistance were achieved at intermediate specific throughputs, whereas the maximum TPS particle size and the lowest color difference were obtained at high specific throughputs. A decrease of color difference from 6.4 to 2.2 was observed by reducing the temperature profile in 5 °C. In the case of blown film extrusion, increasing the temperature profile resulted in a reduction of color difference of the films from 7.9 to 4.2. In addition, tensile strength and strain at break slightly increased. Color difference decreased with decreasing screw speed as well. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47990.     

Potato peeling costreams as raw materials for biopolymer film preparation

Potato peel mass is a costream produced in large quantities by the food industry. Its availability and the presence of starch (46%), pectin, and cellulose make it a potential renewable raw material for polymer products. In this study, biopolymer films were produced from potato peel mass and glycerol. High‐pressure homogenization (HPH) and HPH combined with heat treatment were investigated as pretreatment technologies before film casting. HPH‐treated potato peel mass yielded biopolymer films with similar barrier and mechanical properties as films prepared from pure potato starch, including complete impermeability to grease. Additional heat treatment of the peel mass enhanced starch gelatinization, resulting in improved barrier properties and smoother surface topography of the films. Films with similar appearance and quality were also obtained from starch‐free potato peel mass, indicating that potato fiber rich in pectin and cellulose is likewise a suitable material for biopolymer film preparation after HPH treatment. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42862.     

Aging properties and hydrophilicity of maize starch plasticized by hyperbranched poly(citrate glyceride)

Hyperbranched poly(citrate glyceride)s (HBPETs) as plasticizers were mixed with maize starch (S) via cooking and film formation. The structure, aging properties, and hydrophilicity of the plasticized starches were studied by means of Fourier transform infrared spectroscopy, X-ray diffraction, tension testing, contact angle testing, solubility measurements, moisture absorption, and water vapor permeability (WVP). Compared with a glycerol–S plasticized film, the HBPET–S composite films had better mechanical properties in terms of both strength and elongation at break, better aging resistance, less moisture absorption, less WVP, and more hydrophobicity on the film surface. The mechanisms behind the performances resulted from stronger and more stable H bonds between the abundant active end groups of HBPET and hydroxyls of starch and the high branching degree of the HBPETs; this was helpful for effectively inhibiting the recrystallization of starch. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46899.     

Structure–property relation in polyvinyl alcohol/starch composites

A series of polyvinyl alcohol (PVA)/starch films were cast by the solvent method. Mechanical, optical, wide‐angle X‐ray scattering (WAXS), and biodegradation studies of starch‐filled PVA films were carried out. With the addition of starch there was an increase in haze and diffusion of light, whereas there was only slight change associated with tensile behavior and burst strength of the PVA film. Microstructural parameters, such as crystal size (〈N〉) and lattice distortion (g, in %) were estimated using one‐dimensional Hosemann's paracrystalline model along with WAXS data. These parameters quantify the changes in the PVA/starch systems, which resulted in the observed physical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 12: 630–635, 2004     

pH sensitive phosphate crosslinked films of starch-carboxymethyl cellulose

This work aims to develop hydrogel films of starch and carboxymethyl cellulose (CMC) crosslinked with sodium trimetaphosphate (STMP) and to characterize some of their properties. Starch and STMP (S/T), starch and CMC (S/C), and mixed (S/T/C) films were prepared by casting. The degree of substitution, morphology, swelling degree, FTIR, mechanical properties, and sorption isotherms were studied. Reticulated samples (S/T and S/T/C) showed the same degree of substitution (0.050 ± 0.001). All films presented homogeneous morphology, but the mixed film showed greater roughness. Crosslinking increased the swelling capacity of the mixed hydrogel at pH 7, although it remained decreased concerning the S/T hydrogel. However, this property was sensitive to pH variations. The mixed film (S/T/C) showed greater mechanical resistance. The casting process was efficient to produce hydrogel films of starch/CMC crosslinked with STMP and the general results demonstrated the advantages of the mixed hydrogel.     

Improved mechanical and barrier properties of starch film with reduced graphene oxide modified by SDBS

Starch is regarded as one of the most promising biopolymers to replace the fossil resources. However, due to the poor mechanical properties, high sensitivity to humidity, and low barrier property, the development of starch‐based materials has been limited. In this study, they improved the mechanical and barrier properties of starch film with reduced graphene oxide (RGO) modified by sodium dodecyl benzene sulfonate (SDBS). The hydrophilia of modified RGO (r‐RGO) was improved and result in a good dispersion in oxidized starch (OS) matrix. The tensile strength of the r‐RGO‐4/OS film increased to 58.5 MPa which was more than three times of the OS film (17.2 MPa). Besides, both the water vapor and oxygen barrier properties of r‐RGO/OS film were improved greatly compared with OS and GO/OS films. Moreover, the r‐RGO/OS film could protect against UV light effectively due to its lightproof performance. In conclusion, the r‐RGO/OS composite film has great potential applications in packaging industry. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44910.     

Improving the toughening in poly(lactic acid)‐thermoplastic cassava starch reactive blends

Poly(lactic acid) (PLA), a physical blend of PLA and thermoplastic cassava starch (TPCS) (PLA‐TPCS), and reactive blends of PLA with TPCS using maleic anhydride as compatibilizer with two different peroxide initiators [i.e., 2,5‐bis(tert‐butylperoxy)‐2,5‐dimethylhexane (L101) and dicumyl peroxide (DCP)] PLA‐g‐TPCS‐L101 and PLA‐g‐TPCS‐DCP were produced and characterized. Blends were produced using either a mixer unit or twin‐screw extruder. Films for testing were produced by compression molding and cast film extrusion. Morphological, mechanical, thermomechanical, thermal, and optical properties of the samples were assessed. Blends produced with the twin‐screw extruder resulted in a better grade of mixing than blends produced with the mixer. Reactive compatibilization improved the interfacial adhesion of PLA and TPCS. Scanning electron microscopy images of the physical blend showed larger TPCS domains in the PLA matrix due to poor compatibilization. However, reactive blends revealed smaller TPCS domains and better interfacial adhesion of TPCS to the PLA matrix when DCP was used as initiator. Reactive blends exhibited high values for elongation at break without an improvement in tensile strength. PLA‐g‐TPCS‐DCP provides promising properties as a tougher biodegradable film. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46140.     

Impact of the starch source on the physicochemical properties and biodegradability of different starch‐based films

Concern about environmental issues has motivated research into the development of biodegradable packaging from renewable sources. Natural polymers such as starch constitute a good alternative for diminishing the use of nonbiodegradable and nonrenewable components in the packaging industry. However, depending on the botanical source, films with different properties are formed. The aim of this study was to evaluate the film‐forming capacity of different starch sources (cassava, corn, potato, and wheat) by casting with starch contents from 2 to 6%. Principal component analysis methodology was used to evaluate the correlation between the formulations and their physicochemical and mechanical properties. It was not possible to produce continuous films based on potato starch, probably because of its very low amylose content (10%). The corn‐, cassava‐, and wheat‐starch‐based films were characterized by their thicknesses (0.06–0.22 mm), moisture contents (19–26%), water solubilities (13.7–26.5%), water‐vapor permeabilities (WVPs; 0.19–0.48 g mm h^?1 m^?2 kPa^?1), wettabilities (35–106°), biodegradabilities in soil, and thermal and mechanical properties (tensile strength = 1.9–6.7 MPa, elongation = 41–166%, and Young's modulus = 8–127 MPa). The wheat starch films presented higher WVPs and lower mechanical properties. The cassava starch films presented lower wettabilities and good mechanical properties; this suggested that their use in packaging for products, such as fruits and vegetables, with higher water activities could be feasible. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46564.     

Antioxidant films based on gelatin capsules and minimally processed beet root (Beta vulgaris L. var. Conditiva) residues

Biocomposite films were prepared by incorporating different concentrations of beet root residue powder (BRP) (2, 4, 8, and 12 g BRP/100 g water) into films based on residues of gelatin capsules (GCR) (40 g GCR/100 g water). Control films had no BRP added. A complete mechanical, physicochemical, barrier, optical, and antioxidant characterization of all films was performed. Among all the films considered, BRP12 was found to present the most adequate properties and was further investigated. SEM micrographs showed that BRP12 presented a less homogeneous surface in comparison with the control film, but they showed similar thermal stability. After 15 days of soil degradation, the films lost over 75% of weight. The films were effective on protecting sunflower oil from primary oxidation process, and BRP12 showed higher protection than control film. Therefore, this study suggests that the formulated films could act as promising antioxidant materials and contribute to environmentally friendly technologies. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43094.     

Effect of an allyl pretreatment of starch on the grafting efficiency and properties of allyl starch‐g‐poly(acrylic acid)

Starch was pretreated with allyl etherification to enhance the grafting efficiency of the copolymerization of granular starch with acrylic acid and to improve the properties of starch‐g‐poly(acrylic acid) used as a warp sizing agent. The graft copolymerization was carried out in an aqueous dispersion with ferrous ammonium sulfate and hydrogen peroxide as initiators. Through the introduction of allyl groups into starch before the copolymerization, the grafting efficiency could evidently be enhanced, and properties such as fiber adhesion and film behaviors of the copolymer were improved. The pretreatment was capable of enhancing the grafting efficiency by about 10–20% when the degree of substitution of allyl starch ranged from 0.011 to 0.037. The adhesion and film behaviors also depended on the modification extent of the starch pretreatment and on the grafting ratio of the copolymer. The adhesion reached a maximum at a degree of substitution of 0.025, and the film behaviors were best when the degree of substitution ranged from 0.011 to 0.025. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Mechanical and barrier properties of edible starch–protein‐based films

The present investigation dealt with the mechanical properties, water‐vapor transmission behavior at different relative humidity conditions, and DSC thermograms of edible films formulated using various proteins (casein, gelatin, albumin) in combination with starch and nonthermal as well as intense thermal blending. Nonthermal blended film showed in the DSC thermogram a double T_g, indicating poor miscibility of the components and, hence, a poor film‐forming property. However, the DSC thermogram of all the films based on intense thermal blending showed a single T_g, indicating the complete molecular miscibility of the components. Casein‐based film showed a lower water‐vapor transmission rate, water gain at different relative humidity conditions, and higher tensile strength compared to its counterparts containing gelatin and albumin. Since the casein–starch blend gave better film properties, a blend of hydrophobic carnauba wax and casein was prepared to compare the properties of hydrophilic–hydrophilic and hydrophobic–hydrophilic blends. Both these blends compared well with respect to the water‐vapor transmission rate. Wax‐based film showed multiphased behavior in the DSC thermograms and the percent elongation was lower as compared to the casein–starch blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 64–71, 2003     

Ionic liquids as performance additives for water‐based printing inks

For the first time, the use of ionic liquids as additives for printing inks in order to improve the wettability of the printing base by the ink is presented. The aim of this work was to study the influence of ionic liquids on the selected properties of water‐based printing ink and the prints. The contact angles of the printing inks on the printing base were measured. Modified flexographic inks were laboratory printed on polypropylene plastic film. The impact of small amounts of various ionic liquids on printing ink colour was examined in terms of the optical density of the full‐tone area, the colour parameters (L*, a*, b*, CIE), the total colour difference, and the gloss of the dried ink film. The influence of ionic liquids on the ink contact angle, the optical density, and the L*a*b* coordinates is discussed. In general, the investigated ionic liquids improve the wettability of water‐based flexographic printing ink, with an acceptable total colour difference. The optical density is increased for printing inks containing ionic liquids in comparison with the original flexographic printing ink, Process.     

Performance of different process additives on the properties of mango powder obtained by drum drying

The use of process additives was evaluated in the drum drying of commercial mango pulp, using corn starch, maltodextrin 10/20 DE, and glyceryl monostearate (GMS). The mass flow rate (MFR) and some powder properties were analyzed: moisture content, vitamin C, total phenolic compounds, carotenoids, β-carotene, glass transition temperature (T_g), hygroscopicity, solubility, color, rheological behavior and color of reconstituted pulp. The pulps presented non-Newtonian and pseudoplastic fluid behavior, while T_g values ranged from 29°C to 38°C. The process performed with 3% corn starch and 0.5% GMS (dry basis) resulted in greater MFR (8.0?±?0.2?kg/h?m²) and vitamin C retention (61.0?±?0.7%).     

High temperature stable photopatternable copolymers: Synthesis,optical properties,and photopatterning process studies

Photopatternable copolymers and photopatterning processes for high temperature stable optical elements have been studied. The photopatternable copolymers were synthesized from methyl methacrylate and methacrylic ester comprising a nonconjugate carbon–carbon double bond side chain and epoxy side chain. Their optical properties were investigated on film samples doped with m-benzoylbenzophenone (BBP). After irradiating with UV light, insoluble polymer was formed in a high yield at higher temperature, resulting in changes in thickness and refractive index, which were precisely controlled by the exposure energy of UV light. The two step photopatterning processes were carried out by means of UV irradiations with and without a photomask bearing a grating pattern followed by removal of unreacted BBP to draw an optical pattern on the polymer material with cross-linking. Further photoreaction was also performed to cure the polymer by exposure with a high energy UV lamp containing shorter wavelength light after the patterning process. By a combination of the patterning process and the postcuring process, an optical grating fabricated from these copolymers showed a heat stability up to 160°C. © 1994 John Wiley & Sons, Inc.     

Photobiodegradation of low‐density polyethylene/banana starch films

The effects of the starch content, photosensitizer content, and compatibilizer on the photobiodegradability of low‐density polyethylene (LDPE) and banana starch polymer blend films were investigated. The compatibilizer and photosensitizer used in the films were PE‐graft‐maleic anhydride (PE‐g‐MA) and benzophenone, respectively. Dried banana starch at 0–20% (w/w) of LDPE, benzophenone at 0–1% (w/w) of LDPE, and PE‐g‐MA at 10% (w/w) of banana starch were added to LDPE. The photodegradation of the blend films was performed with outdoor exposure. The progress of the photodegradation was followed by determining the carbonyl index derived from Fourier transform IR measurements and the changes in tensile properties. Biodegradation of the blend films was investigated by a soil burial test. The biodegradation process was followed by measuring the changes in the physical appearance, weight loss, and tensile properties of the films. The results showed that both photo‐ and biodegradation rates increased with increasing amounts of banana starch, whereas the tensile properties of the films decreased. The blends with higher amounts of benzophenone showed higher rates of photodegradation, although their biodegradation rates were reduced with an increase in benzophenone content. The addition of PE‐g‐MA into polymer blends led to an increase in the tensile properties whereas the photobiodegradation was slightly decreased compared to the films without PE‐g‐MA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2725–2736, 2006     

Effects of nano‐tio2 on the performance of high‐amylose starch based antibacterial films

The purpose of this article is to investigate the effects of nano‐tianium dioxide (nano‐TiO₂) on the high‐amylose starch/polyvingl alcohol (PVA) blend films prepared by a solution casting method. The results show that at the concentration of 0.6% of nano‐TiO₂, the film demonstrated the best tensile strength at 9.53 MPa, and the elongation at break was noted as 49.50%. The optical transmittance of the film was decreased and the water resistance was improved with further increase of the concentration of nano‐TiO₂. Using the techniques of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and field‐emission scanning electron microscopy (SEM), the molecular and the crystal structures of the films were characterized. The results indicate that the miscibility and compatibility between high‐amylose starch and PVA were increased with the addition of nano‐TiO₂ into the films due to the formation of hydrogen and C? O? Ti bonds. The antimicrobial activities of the blend films were also explored. The results show that there were inhibitory zones around the circular film disc, which is attributable to the addition of nano‐TiO₂. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42339.     

New breathable films using a thermoplastic cross‐linked starch as a porogen

Breathable films, which find in variety of product applications, are conventionally made using mineral porogens such as calcium carbonate (CaCO₃). This article addresses a novel biodegradable and highly breathable film without inorganic porogens. Unexpectedly, a thermoplastic cross‐linked natural polymer (corn starch) was used successfully to create tortuous passages for film breathability. This concept was demonstrated using two types of thermoplastic cross‐linked corn starches as porogens and contrasted to control samples: native corn and chemically cross‐linked starches, respectively. The films discussed had increased breathability and mechanical properties relative to the control samples. The film morphology reveals that filler was irregular when thermoplastic starch or CaCO₃ was used. The difference in filler from chemically modified cross‐linked starch and thermoplastic cross‐linked starch was observable as well. It is believed that spherical particles provided by thermoplastic cross‐linked starch helps film debonding and porosity during the film stretch processes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41016.     

Synthesis and evaluation of fluorosilicone‐modified starch for protection of historic stone

Starch is sensitive to moisture and is weak to durability in the protection application to ancient relics. Therefore, two fluorosilicone‐modified starches are firstly prepared and evaluated for the protection of historic stones. The fluoro‐silicone copolymer grafted starch of P(VTMS/12FMA)‐g‐starch is synthesized by grafting copolymer of vinyltrimethoxysilane (VTMS) and dodecafluoroheptyl methacrylate (12FMA) onto starch. While the fluoro‐silicone starch latex of VTMS‐starch@P(MMA/BA/3FMA) is obtained by emulsion polymerization of VTMS primarily grafted‐starch (VTMS‐starch) with methyl methacrylate (MMA), butyl acrylate (BA) and 2,2,2‐trifluoroethyl methacrylate (3FMA). The grafting fluorosilicone copolymer onto starch improves obviously their hydrophobic and thermal properties. Comparatively, VTMS‐starch@P(MMA/BA/3FMA) film performs higher water contact angle (107°) and thermal stability (350–430°C) than p(VTMS/12FMA)‐g‐starch film (72°, 250–420°C) due to the migration of fluorine‐containing group onto the surface of film during the film formation. Therefore, VTMS‐starch@P(MMA/BA/3FMA) shows much better protective performance in water‐resistance, and salt/freeze‐thaw resistance for stone samples. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41650.