Biodegradable plastic modification from durian seed starch and shrimp chitosan with the addition of plasticiziers glycerol and polyglycerol using microwaves

Plastic waste takes up to 450 years to decompose. These problems can be overcome by creating other alternatives, one of which is by using biodegradable plastic. Biodegradable plastics are plastics made from natural polymers that are easily degraded by microorganisms. This study aims to examine the effect of the amount of plasticizer on the length of the degradation process and the effect of using microwaves on the length of time for molding biodegradable plastic. This biodegradable plastic is made by combining durian seed starch, shrimp chitosan and plasticizers in the form of glycerol and polyglycerol with volume variations of 1 mL, 2 mL, 3 mL, 4 mL, and 5 mL. This polymerization was carried out using a microwave with a power of 100 watts for 60 minutes. The resulting biodegradable plastics were characterized using the FTIR test, the Mechanical Properties test, the Absorbency test, and the Biodegradation test to determine the quality of the biodegradable plastic. The results of this study indicate the greatest tensile strength value is 1.9768 MPa, the largest elongation value is 21.2772%, the smallest water absorption is 45.40% for 5 minutes, and the largest degraded mass is 0.908 grams for 7 days. Based on this research, it can be concluded that the use of polyglycerol can accelerate the plastic degradation process. In addition, the use of microwaves can speed up the molding time of biodegradable plastics.

Bacterial Abundance, Diversity and Activity During Long-Term Colonization of Non-biodegradable and Biodegradable Plastics in Seawater

The microorganisms living on plastics called “plastisphere” have been classically described as very abundant, highly diverse, and very specific when compared to the surrounding environments, but their potential ability to biodegrade various plastic types in natural conditions have been poorly investigated. Here, we follow the successive phases of biofilm development and maturation after long-term immersion in seawater (7 months) on conventional [fossil-based polyethylene (PE) and polystyrene (PS)] and biodegradable plastics [biobased polylactic acid (PLA) and polyhydroxybutyrate-co-hydroxyvalerate (PHBV), or fossil-based polycaprolactone (PCL)], as well as on artificially aged or non-aged PE without or with prooxidant additives [oxobiodegradable (OXO)]. First, we confirmed that the classical primo-colonization and growth phases of the biofilms that occurred during the first 10 days of immersion in seawater were more or less independent of the plastic type. After only 1 month, we found congruent signs of biodegradation for some bio-based and also fossil-based materials. A continuous growth of the biofilm during the 7 months of observation (measured by epifluorescence microscopy and flow cytometry) was found on PHBV, PCL, and artificially aged OXO, together with a continuous increase in intracellular (3H-leucine incorporation) and extracellular activities (lipase, aminopeptidase, and β-glucosidase) as well as subsequent changes in biofilm diversity that became specific to each polymer type (16S rRNA metabarcoding). No sign of biodegradation was visible for PE, PS, and PLA under our experimental conditions. We also provide a list of operational taxonomic units (OTUs) potentially involved in the biodegradation of these polymers under natural seawater conditions, such as Pseudohongiella sp. and Marinobacter sp. on PCL, Marinicella litoralis and Celeribacter sp. on PHBV, or Myxococcales on artificially aged OXO. This study opens new routes for a deeper understanding of the polymers’ biodegradability in seawaters, especially when considering an alternative to conventional fossil-based plastics.

PENAMBAHAN CHITOSAN DAN PLASTICIZERGLYCERIN DALAM PEMBUATAN BIOPLASTIK BERBAHAN DASAR EKSTRAK PROTEIN AMPAS TAHU

Plastik sintetis merupakan plastik yang biasanya berbasis konvensional. Sumber bahan baku plastik sintetis merupakan energi yang tidak dapat diperbarui yaitu minyak bumi. Plastik sintetis memiliki sifat fisik yang fleksibel, ringan, kuat dan ekonomis. Plastik sintetis dapat menyebabkan permasalahan lingkungan yaitu sulitnya plastik sintetis yang terdegradasi oleh tanah. Sehingga dapat menurunkan kualitas tanah dan mikriorganisme. Upaya pencegahan permasalahan sampah plastik dapat dilakukan dengan pengembangan pembuatan plastik dari bahan polimer alami yang disebut bioplastik. Plastik biodegradableumumnya terbuat dari bahan polisakarida dan dapat terbuat dari sumber protein, salah satunya limbah tahu. Penelitian ini bertujuan untuk memanfaatkan limbah tahu yang diekstrak untuk diambil proteinnyasebagai bahan dasar pembuatan plastik biodegradable, serta untuk mengetahui sifat mekanik dan lama bioplastik protein ampas tahu terdegradasi oleh tanah. Pembuatan bioplastik membutuhakan bahan pemlastis dan bahan aditif untuk menghasilkan plastik yang fleksibel. Penelitian ini menggunakan penambahan plasticizerglycerin dengan variasi 30%,40%,50% dan bahan pengisi 20%. Penambahan chitosan sebanyak 5 ml. Hasil penelitian pembuatan protein ampas tahu menunjukkan bahwa kadar protein ampas tahu yang dihasilkan dari tahap diekstraksi sebesar 29.72%. Hasil pengujian kuat tarik bioplasik dari protein ampa tahu menggunakan alat UTM (Universal Testing Machine) yangberkisar antara 1.04-2.12 Mpa yang telah memenuhi standar bioplastik menurut Japan Industrial Standard (JIS). Sedangkan hasil pengujian daya serap air menggunakan metode swelling memiliki nilai tertinggi pada glycerin 50% sebesar 196% dalam kurun waktu 30 menit. Sedangkan daya serap paling baik terdapat pada variasi glycerin 30% sebesar 49.7%. Bioplastik berbahan dasar protein ampas tahu dapat terdegrdasi dengan sempurna dalam kisaran waktu 7-14 hari. Kata kunci: biodegradable plastik, biodegradasi, chitosan, glycerin, sifat mekanik. Synthetic plastics are plastics that are usually conventional based. The source of synthetic plastic raw material is non-renewable energy, namely petroleum. Synthetic plastics have physical properties that are flexible, lightweight, strong and economical. Synthetic plastics can cause environmental problems, namely the difficulty of synthetic plastics which are degraded by soil. So that it can reduce soil quality and microorganisms. Efforts to prevent the problem of plastic waste can be done by developing the manufacture of plastics from natural polymer materials called bioplastics. Biodegradable plastics are generally made of polysaccharides and can be made from protein sources, one of which is tofu waste. This study aims to utilize the extracted tofu waste for protein as a basic material for making biodegradable plastics, as well as to determine the mechanical properties and length of time for the tofu pulp protein to be degraded by the soil. The manufacture of bioplastics requires plasticizers and additives to produce flexible plastics. This study used the addition of glycerol plasticizer with a variation of 30%, 40%, 50% and 20% filler. The addition of 5 ml of chitosan. The results of the research on making tofu pulp protein showed that the protein content of tofu pulp from the extraction process was 29.72%. Bioplastic tensile strength value from tofu pulp ranges from 1.04-2.12 MPa which has met the bioplastic standards according to the Japan Industrial Standard (JIS). The highest water absorption capacity of bioplastics from tofu pulp protein was found in the glycerol 50% variation of 196% within 30 minutes. Meanwhile, the lowest absorption rate was found in the 30% glycerol variation of 49.7%. Bioplastics from tofu pulp protein can completely decompose in 7-14 days. Keywords: chitosan, degradation, glycerol, mechanical properties, plastic biodegradable.

General Aspects of Biodegradable Biopolymers and the Polyhydroxyalkanoates’ Family

Background: Plastic polymers are ubiquitous and life without them is practically impossible. Despite the advantages provided by the material, conventional plastics are also harmful to the environment and human health. Therefore, the search for alternatives, such as polyhydroxyalkanoates (PHAs), a family of biodegradable thermoplastic polyesters naturally produced by PHA-accumulating bacteria, such as Pseudomonas spp. and Ralstonia eutropha, through fermentative processes, is of paramount importance. Objectives: In the present work, the objective of the researchers was to develop a revisional study regarding biodegradable biopolymers and the PHAs’ importance and benefits for society and the environment. Methods: In this review, articles published since the year 2000, related to the different aspects of biodegradable plastics and PHAs, were accurately analyzed and reviewed. The subjects covered ranged from conventional plastics and the problems related to their large-scale production and the importance of biodegradable plastics, as well as PHAs, their positive aspects, and the feasibility of their use as an alternative to replace conventional plastics. Those subjects were extensively reviewed and concisely discussed. Results and Conclusions: The present study demonstrated the importance of biodegradable plastics and the PHAs’ family, its different application possibilities, and its viability as an alternative to replace conventional plastics, since it can mimic their characteristics efficiently, with the advantage of being biodegradable and produced from renewable sources.