Nanocellulose Reinforced Thermoplastic Starch (TPS), Polylactic Acid (PLA), and Polybutylene Succinate (PBS) for Food Packaging Applications

Abstract

Synthetic plastics are severely detrimental to the environment because nonbiodegradable plastics do not degrade for hundreds of years. Nowadays, these plastics are very commonly used for food packaging. To overcome this problem, food packaging materials should be substituted with "green" or environmentally friendly materials, normally in the form of natural fiber reinforced biopolymer composites. Thermoplastic starch (TPS), polylactic acid (PLA) and polybutylene succinate (PBS) were chosen for the substitution, because of their availability, biodegradability, and good food contact properties. Plasticizer (glycerol) was used to modify the starch, such as TPS under a heating condition, which improved its processability. TPS films are sensitive to moisture and their mechanical properties are generally not suitable for food packaging if used alone, while PLA and PBS have a low oxygen barrier but good mechanical properties and processability. In general, TPS, PLA, and PBS need to be modified for food packaging requirements. Natural fibers are often incorporated as reinforcements into TPS, PLA, and PBS to overcome their weaknesses. Natural fibers are normally used in the form of fibers, fillers, celluloses, and nanocelluloses, but the focus of this paper is on nanocellulose. Nanocellulose reinforced polymer composites demonstrate an improvement in mechanical, barrier, and thermal properties. The addition of compatibilizer as a coupling agent promotes a fine dispersion of nanocelluloses in polymer. Additionally, nanocellulose and TPS are also mixed with PLA and PBS because they are costly, despite having commendable properties. Starch and natural fibers are utilized as fillers because they are abundant, cheap and biodegradable.

Antimicrobial Activities of Starch-Based Biopolymers and Biocomposites Incorporated with Plant Essential Oils: A Review

“…The biodegradable film retains food quality and is environmentally friendly [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Although several kinds of new polymers such as (polylactic acid (PLA), polyhydroxyalkanoates (PHA), polycaprolactone (PCL), and poly(ethylene adipate) (PEA) are industrially produced, agricultural based polymers are the most investigated by researchers, mainly polysaccharides [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Numerous researchers reported that reinforcement of essential oil into starch based packaging can increase their stability and retain their flavour and functional properties [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ].…”

The Effects of Unbleached and Bleached Nanocellulose on the Thermal and Flammability of Polypropylene-Reinforced Kenaf Core Hybrid Polymer Bionanocomposites

“…The other advantages include low density, renewability, biodegradability, non-toxicity, good insulation property and low machine wear [ 13 , 21 ]. However, the common disadvantages of natural fibers are their hydrophilic nature, which leads to lower interfacial bonding and surface adhesion with the matrix, which has been reported by many researchers [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. This behavior leads to the deterioration of the properties of the biocomposites.…”

Micro- and Nanocellulose in Polymer Composite Materials: A Review

“…As nanocellulose is used to reinforce synthesis polymer, it is also employed to reinforce biopolymer from natural resources to improve the properties of the natural polymer, such as polylactic acid (PLA), polyhydroxy acids (PHA), polyhydroxybutyrate (PHB), polybutylene succinate (PBS), and starch biopolymer [ 210 , 211 ]. Table 3 and Table 4 illustrate some examples of NCC and NFC reinforced biopolymer and show the effects of NCC as well as NFC fillers.…”