Table 1.

Plasticizers that are used in alginate-based films.

Bio-Polymer	Plasticizer	Findings and Results	Refs.
Alginate and gelatin	Glycerol and water	Increasing RH led to increased TS and decreased EB, and glycerol increased the flexibility of the films without altering TS.	[52]
Alginate and pectin	50% glycerol and water (53% RH)	The absorbed water during conditioning had a plasticizing effect on the films.	[53]
Chitosan and alginate	25, 40, and 50% glycerol and sorbitol–water	A dramatic decrease in Tg with the incorporation of glycerol and water.	[54]
Alginate (M/G = 0.45 and M/G = 1.5)	Fructose, glycerol, sorbitol, and polyethylene glycol (PEG-8000)	WVP was higher for the films conditioned at higher RH; PEG-plasticized films were opaque because of phase separation.	[31]
Alginate	Glycerol and water	Films conditioned at 100% RH had higher EB and lower TS and YM than films conditioned at 57% RH.	[55]
Alginate and other carbohydrates	water	Wet alginate films had higher EB than dried films because of the plasticizing effect of water.	[56]
Alginate	Glycerol and water	There was a remarkable decrease in the degradation temperature of the film plasticized with 50% glycerol. Increasing glycerol content beyond 30% led to the segregation phenomenon.	[19]
Alginate	Glycerol, sorbitol, and water	The glycerol-plasticized film had lower Tg than the sorbitol-plasticized one, The films obtained from the solvent casting method had higher TS and YM, but lower EB compared with the thermo-mechanical mixing method.	[47]
Corn starch (CS) and sodium alginate (SA)	15% glycerol and water	A twin-screw extruder was used for blending the materials, and glycerol and water decreased the processing temperature.	[57]
Alginate	Glycerol (20–40%) and sorbitol (30–50%)	Although glycerol is a more effective plasticizer based on mass content, the plasticizing efficiency of sorbitol was higher at the molecular basis.	[15]
Alginate	Glycerol	Glycerol and calcium chloride (crosslinker) had a synergistic effect on the mechanical properties of the films, and beyond a certain limit they had a deteriorating effect.	[13]
Alginate (high guluronic acid (Ap) and low guluronic acid (Ar))	Glycerol	Ap polymer was effectively plasticized because of its buckled structure.	[17]
Alginate and low acyl gellan	Glycerol	The optimal concentration of glycerol was 8% v/v.	[58]
Alginate	Glycerol	At temperatures above 40 °C, a significant amount of glycerol was lost.	[59]
Alginate/pectin	Glycerol	When the plasticizer concentration was above a critical limit, phase separation could be observed on the surface of the film.	[29]
Alginate	Polyglycerol	Polyglycerol had an anti-plasticization effect on alginate because of the presence of high amounts of hydroxyl groups in polyglycerol.	[45]
Alginate	glycerin and polyethylene glycol 400 (PEG400)	Glycerin was a better plasticizer than PEG400 and gave more flexibility to the films because of the lower molecular weight of glycerin.	[30]
Alginate	glycerol (GLY), diethylene glycol (DEG), and polyethylene glycol (PEG)	WVP of films plasticized with PEG and DEG was lower than that of GLY-plasticized film.	[42]
Alginate	Glycerol, Xylitol, and mannitol	Glycerol and xylitol-plasticized films were more transparent and uniform than the mannitol-plasticized film, but they had higher WVP.	[60]
Alginate and vegetable oils	Glycerol and sorbitol (0–20%)	The surface tension did not alter by the addition of the plasticizers, but vegetable oils diminished the surface tension.	[61]
Pullulan and alginate	glycerol, sorbitol, xylitol, and fructose	Sorbitol- and fructose-plasticized blend films exhibited the lowest and similar EB at any given plasticizer concentrations compared with glycerol and xylitol-plasticized films, with the fructose-plasticized film being even more brittle with higher TS and lower EB.	[36]
Alginate and pectin	Glycerol	Increasing glycerol content promoted the WVP of the films.	[62]
Alginate and pectin	33% Polyglycerol	Higher swelling degree cross-linked film with the addition of polyglycerol.	[8]
Alginate and apple puree	Glycerol, rapeseed oil, coconut oil, hazelnut oil, and sugars in the apple puree	The Tg decreased with the addition of vegetable oils and apple puree, so they had a plasticizing effect.	[63]
Alginate	Glycerol and oregano essential oil (OEO)	Higher EB and lower WVP and TS observed with the incorporation of OEO.	[51]
Alginate	Glycerol, castor oil (CO)	The incorporation of CO led to increased EB and decreased TS and WVP.	[64]
Alginate	Glycerol and soybean oil	At high calcium chloride concentrations, the EB of alginate decreased with increasing oil concentrations. WVP decreased with the addition of oil.	[65]
Alginate (2–6%) and virgin coconut oil	Glycerol (10%)	To decrease the surface tension of oil and alginate, ethanol was used.	[66]
Alginate/gelatin	Glycerol and canola oil	Higher EB and lower WVP and TS observed with the incorporation of canola oil.	[67]
Alginate	Glycerol and cinnamon essential oil (CEO)	The incorporation of higher amounts of CEOs led to a decreased EB.	[68]
Alginate	Glycerol and cinnamon essential oil (CEO)	The incorporation of the CEO led to an increased EB and WVP and decreased TS.	[69]
Alginate/garlic oil	-	Garlic oil increased EB and decreased TS of the film, and WVP increased remarkably with increasing oil content.	[70]
Alginate	Glycerol, essential oils (Eos)	Oil droplets had a plasticizing effect by decreasing interactions between chains.	[71]
Alginate/apple puree	Glycerol and plant essential oils	EB increased with the addition of the oil, but TS decreased.	[72]
Soy protein isolate/alginate	Stearic acid and lauric acid	TS and EB of the films decreased with the incorporation of the fatty acids; however, EB increased at higher concentrations of auric acid. WVP value decreased at lower amounts of fatty acids, but it increased at higher amounts.	[50]
Alginate	Glycerol and oleic acid	Oleic acid behaved like a second plasticizer.	[3]
Alginate	Glycerol, tri-butyl citrate (TC)	TC-plasticized films were opaque; Tg and TS increased with the addition of TC; EB decreased with the addition of TC.	[33]
Alginate	Citric acid (CA)	CA at higher concentrations had a plasticizing effect.	[34]
Chitosan/alginate	Triacetin, glycerol, and Ionic liquid	Triacetin-plasticized films were brittle and thermally stable.	[44]
Alginate	Graft copolymerization of itaconic acid (internal plasticization)	The Tg value of the grafted alginate film was lower, indicating the plasticizing effect of itaconic acid.	[73]
Natural polysaccharides such as alginate	Graft copolymerization of polyacrylonitrile (internal plasticization)	The grafted chains might act as internal plasticizers because of the reduced Tg.	[74]
Alginate	Lemon and fennel wastes (contain pectin-like polymers)	Tg and degradation temperature decreased, but the EB and TS of the films increased with the incorporation of the plasticizers.	[75]
Alginate/lignin	Glycerol and lignin	Lignin exerts an apparent plasticizing effect on alginate by reducing the intermolecular interaction between chains and decreasing the tensile strength of the films.	[76]
Gluronate-rich (MG) and mannuronate-rich (MC) alginate	Water and hot air	Plasticity was decreased by increasing the drying temperature to 60 °C, Hot air at 80 °C induced plasticity because of the formation of bubbles and degradation of alginate molecules.	[22]
Alginate	Glycerol	The amount of glycerol in the dried films was decreased by increasing the drying temperature; hence, the properties of the film were affected.	[77]
Alginate	-	According to thermo-mechanical analysis, the films prepared at 80 °C were more plasticized than the films produced at lower temperatures.	[78]

RH = Relative Humidity, YM = Young’s modulus, TS = Tensile Strength, EB = Elongation at the break, WVP = Water Vapor Permeability, T_g = Glass Transition Temperature.