Enhancement in the physico-mechanical functions of seaweed biopolymer film via embedding fillers for plasticulture application-A comparison with conventional biodegradable mulch film

Abstract

This study aimed to compare the performance of fabricated microbially induced precipitated calcium carbonate- (MB-CaCO 3 ) based red seaweed (Kappaphycus alvarezii) bio-polymer film and commercial calcium carbonate- (C-CaCO 3 ) based red seaweed bio-film with the conventional biodegradable mulch film. To the best of our knowledge, there has been limited research on the application of commercial CaCO 3 (C-CaCO 3 ) and microbially induced CaCO 3 (MB-CaCO 3 ) as fillers for the preparation of films from seaweed bio-polymer and comparison with biodegradable commercial plasticulture packaging. The results revealed that the mechanical, contact angle, and biodegradability properties of the polymer composite films incorporated with C-CaCO 3 and MB-CaCO 3 fillers were comparable or even superior than the conventional biodegradable mulch film. The seaweed polymer film incorporated with MB-CaCO 3 showed the highest contact angle of 100.94°, whereas conventional biodegradable mulch film showed a contact angle of 90.25°. The enhanced contact angle of MB-CaCO 3 resulted in high barrier properties, which is highly desired in the current scenario for plasticulture packaging application. The water vapor permeability of MB-CaCO 3 based seaweed films was low (2.05 ± 1.06 g.m/m 2 .s.Pa) when compared to conventional mulch film (2.68 ± 0.35 g.m/m 2 .s.Pa), which makes the fabricated film an ideal candidate for plasticulture application. The highest tensile strength (TS) was achieved by seaweed-based film filled with commercial CaCO 3 (84.92% higher than conventional mulch film). SEM images of the fractured surfaces of the fabricated films revealed the strong interaction between seaweed and fillers. Furthermore, composite films incorporated with MB-CaCO 3 promote brighter film, better water barrier, hydrophobicity, and biodegradability compared to C-CaCO 3 based seaweed polymer film and conventional mulch film. From this demonstrated work, it can be concluded that the fabricated MB-CaCO 3 based seaweed biopolymer film will be a promising candidate for plasticulture and agricultural application.