CHARACTERISTICS OF MULTI-LAYERED BLEND FILMS FROM TILAPIA SKIN GELATIN AND POLY(LACTIC ACID)-POLYBUTYLENE ADIPATE TEREPHTHALATE

Nowadays, significant research interest is focused on the production of bi-layered or multi-layered films by coating/laminating two or more polymers to enhance the film properties. It has become a common practice to obtain new packaging materials, instead of searching for new materials, which are often costly and time-consuming. Multi-layered films show better properties than single counterpart. The production of multi-layered biodegradable films has thus increased as a result of increasing demand for eco-friendly packagings. Due to the edible/bio-degradable nature, low cost and wide accessibility, gelatin has been used as promising biopolymer. Poly(lactic acid) (PLA), the linear aliphatic and hydrophobic polyester, is regarded as most promising substitute for petroleum-based polymers. PBAT is one kind of biodegradable and adipate-aromatic copolyester, based on the monomer butanediol, adipic acid and terephthalic acid. Lamination/coating is applied to enhance the performance of polymeric films by combining the properties of different types of films into layered films, Therefore, the present study aimed to develop new biodegradable multi-layered blend films from tilapia skin gelatin and PLA-PBAT for food packaging as an alternative to synthetic plastic. Multi-layered blend films based on tilapia skin gelatin and PLA-PBAT were developed and characterized, in comparison with the control gelatin, PLA, PBAT films, PLA-PBAT blend film and PLA-Gelatin-PLA, PBAT-Gelatin-PBAT multi-layered films. The synergetic effect of lamination was evidenced by the enhanced mechanical properties (P<0.05). Multi-layered blend films had lower water vapor permeability and improved water resistance property, compared to control counterpart (P<0.05). Gelatin films showed increased lightness (L*) with coincidental decrease in total color difference (∆E*) in the presence of PLA-PBAT layers (P<0.05). Transparency and solubility of multi-layered blend films were improved (P<0.05). In addition, multi-layered blend films showed the enhanced hydrophobicity and thermal stability as evidenced by increased water contact angle and degradation temperature, respectively. Microstructure of multi-layered blend films (PLA-PBAT/Gelatin/PLA-PBAT) exhibited three different layers. Thus, PLA-PBAT/Gelatin/PLA-PBAT multi-layered blend film with improved properties could serve as an environmental-friendly packaging material in near future