PENGARUH PENAMBAHAN PLA PADA PATI TERPLASTISASI GLISEROL TERHADAP SIFAT MEKANIK BLEND FILM

Poli-asam laktat (PLA) merupakan polimer yang biocompatible, biodegradable, tidak beracun dan nonkarsinogenik bagi tubuh manusia serta berasal dari sumber daya terbarukan, sehingga sangat baik digunakan untuk aplikasi medis dan pengemasan makanan. Pada penggunaannya, PLA masih memiliki kendala karena sifatnya yang getas, mudah rapuh dengan elongation at break kurang dari 10% dan hidrofobik, sehingga membatasi kondisi pemrosesan polimer tersebut. Pati singkong merupakan biopolimer yang kesediaannya cukup berlimpah dengan sifatnya hidrofilik sehingga sangat mudah terdegradasi. Modifikasi PLA dengan cara blending dengan pati singkong terplastisasi gliserol merupakan upaya untuk meningkatkan sifat mekanik berupa tensile strength dan elongation at break blend film. Penelitian ini bertujuan untuk mendapatkan blend film PLA/pati dengan sifat mekanik yang baik. Penelitian ini dilakukan dalam beberapa tahap yaitu pembuatan PLA dari asam laktat, pembuatan pati terplastisasi gliserol dan pembuatan blend film PLA/Pati. Pembuatan PLA dari asam laktat dilakukan dengan metode polikondensasi. Pembuatan pati terplastisasi gliserol yaitu dengan pencampuran (3%w/v) pati singkong dengan gliserol (1%v/v) pada temperatur 65oC. PLA yang dihasilkan pada tahap polikondensasi dicampur dengan pati terplastisasi gliserol pada temperatur 120oC dengan variasi rasio PLA/pati sebesar 0/100; 20/80; 40/60 dan 50/50. Campuran dicetak dalam bentuk lembaran tipis (blend film) dan dikeringkan pada temperatur 70oC selama 6 jam. Sifat mekanik blend film diketahui dengan menganalisis tensile strength dan elongation at break. Hasil yang didapat menunjukan bahwa penambahan PLA meningkatkan nilai tensile strength dan elongation at break blend film. Rasio PLA/starch yang menghasilkan sifat mekanik blend film terbaik adalah 40/60 dengan nilai tensile strength, elongation at break dan swelling masing-masing 2,32 MPa, 21,25% dan 46,44%

PENGARUH PENAMBAHAN FeCl3 DAN AL2O3 TERHADAP KADAR LIGNIN PADA DELIGNIFIKASI TONGKOL JAGUNG DENGAN PELARUT NaOH MENGGUNAKAN BANTUAN GELOMBANG ULTRASONIK

Tongkol jagung merupakan salah satu limbah lignoselulosik yang banyak tersedia di Indonesia salah satunya di Propinsi Banten. Limbah lignoselulosik adalah limbah pertanian yang mengandung selulosa, hemiselulosa, dan lignin. Limbah tongkol jagung, mengandung selulosa (40-60%), hemiselulosa (20-30%) dan lignin (15-30%). Untuk dapat memanfaatkan kandungan selulose yang terkandung pada tongkol jagung secara optimal, maka perlu dipisahkan kandungan lignin yang terdapat pada tongkol jagung tersebut. Penelitian ini bertujuan untuk mengkaji pengaruh penambahan FeCl3 dan AL2O3 pada proses delignifikasi tongkol jangung dengan pelarut NaOH menggunakan bantuan gelombang ultrasonik. Pada penelitian terdahulu, diperoleh kandungan lignin dalam selulosa menggunakan pelarut NaOH dengan bantuan gelombang ultrasonik pada temperatur 60 0C dan frekuensi ultrasonik sebesar 40 KHz yaitu 40%. Oleh karena itu, pada penelitian ini dilakukan proses delignifikasi pada temperatur 60 0C dengan frekuensi ultrasonik sebesar 40 kHz dengan penambahan rasio FeCl3 : NaOH, AL2O3 : NaOH, AL2O3 : FeCl3 dan FeCl3 : AL2O3 masing-masing 0:1 ; 1:1 dan 2:1. Hasil uji dengan menggunakan metode Chesson menunjukkan bahwa kandungan lignin terkecil dalam selulosa adalah 12% pada rasio perbandingan NaOH : AL2O3 1:2

Calorimetry Technique for Observing the Evolution of Dispersed Droplets of Concentrated Water-in-Oil (W/O) Emulsion during Preparation, Storage and Destabilization

In this work, the evolution of dispersed droplets in a water-in-oil (W/O) emulsion during formation, storage, and destabilization was observed using a calorimetry technique. The emulsion was prepared by dispersing drop by drop an aqueous phase into an oil continuous phase at room temperature using a rotor-stator homogenizer. The evolution of droplets during (1) preparation; (2) storage; and (3) destabilization was observed using differential scanning calorimetry (DSC). The samples were gently cooled-down below its solid-liquid equilibrium temperature then heated back above the melting point to determine its freezing temperature. The energy released during the process was recorded in order to get information about the water droplet dispersion state. The mean droplet size distribution of the sample emulsion was correlated to its freezing temperature and the morphology was followed by optical microscopy. The results indicated that the calorimetry technique is so far a very good technique of characterization concentrated W/O emulsions

Optimisation des émulsions (E/H) concentrées : stabilité, encapsulation et relargage de polysaccharides

Cette étude s'inscrit dans le cadre du projet Européen VEGEPHY (VEGEtale-PHYtosanitaire) dont le but est de développer un produit support destiné à être pulvérisé pour protéger les plantes des viroses. Le produit étudié est une émulsion de type eau-dans-huile (E/H) à base d’une solution aqueuse de polysaccharide et d’esterméthylique de colza comme phase continue. Le polysaccharide est utilisé sous forme d'adjuvant afin de modifier les propriétés rhéologiques de la préparation phytosanitaire (bouillie) et ainsi de limiter la dérive des gouttelettes lors de la pulvérisation. Le but est également d’améliorer le contact des gouttes sur le végétal traité. L'objectif de ce travail est de formuler une émulsion (E/H) avec une concentration maximale de polysaccharide, qui soit stable sur le long terme (environ 2 ans) et d'étudier, lors de la mise en œuvre du produit, les mécanismes de relargage dans un laps de temps efficace devant rester inférieur à 600 s. Les émulsions (E/H) concentrées ont été réalisées à l'aide d'un système rotor stator à température ambiante. La phase aqueuse contenant le polysaccharide et du glycérol a été dispersée dans une phase huileuse agitée dans laquelle un surfactant (lécithine ou PolyRicinoléate de PolyGlycérol, PGPR) a préalablement été dissous. Des tests de stabilité ont été menés immédiatement après les phases de préparation ou par un vieillissement accéléré. Différents paramètres qui ont une influence sur cette stabilité ont été étudiés par DSC, observations microscopiques, diffraction laser et mesure des propriétés rhéologiques. Les analyses DSC ont été utilisées poursuivre l'évolution de la taille des gouttes en fonction du temps. En effet, le comportement thermique des émulsions pendant les phases de congélation et de fusion permet de calculer la fraction d’eau congelée dans les gouttelettes et sa mise en relation avec l’évolution de la stabilité des émulsions. Le relargage du polysaccharide (CarboxyMethylCellulose, CMC) est obtenu en deux étapes : déstabilisation de l'émulsion primaire E/H par un produit chimique puis dilution dans l'eau pour obtenir une émulsion (H/E) avec la concentration désirée de polysaccharide dans la phase aqueuse. La déstabilisation a été étudiée en observant l'évolution des gouttelettes par DSC. Le procédé de dilution a été étudié par une mesure de la conductivité de la solution aqueuse couplée à un modèle cinétique de relargage du CMC.La formulation et la stabilité de l'émulsion (E/H) ont montré que la DSC, complétée par d'autres techniques, est une méthode appropriée pour déterminer les caractéristiques des émulsions. L'étude du comportement lors de la congélation montre que la proportion de glace formée dans les gouttelettes durant les tests DSC est en bonne adéquation avec les mesures DSC et les calculs thermodynamiques. L'utilisation du PGPR comme tensioactif et l'ajout du glycérol dans la formulation permettent d'augmenter la stabilité de l'émulsion à long terme. La formulation optimum obtenue contient 3.5 % (m/m) de CMC, 10 % (m/m) de glycérol dans 75 % (v/v) de phase dispersée et 14 % (m/m) de PRPG dans la phase continue. Un modèle empirique peut être utilisé pour décrire la cinétique de relargage. Pour déstabiliser l'émulsion (E/H), la quantité optimum de tensioactif anionique Cynthiorex PMH1125 est de 10 % (m/m) dans première émulsion avec NRe ≥ 4200 et T ≥ 20°C. Dans les conditions réelles d’utilisation de la préparation au champ, le temps minimum de relargage est d'environ 200 secondes.This study is a part of the European project VEGEPHY (VEGEtale-PHYtosanitaire) to develop a product for the crop protection purposes. The product is a concentrated W/O emulsion trapping of a polysaccharide in the aqueous phase and rapeseed methyl ester oil as a continuous phase. Polysaccharide is used as a thickening adjuvant to modify the rheology properties of the water-based spray solution in order to reduce the drift of thespray. The objective of this study is to formulate concentrated W/O emulsions incorporation with the maximum amount of polysaccharide which show long stability (for over 2 years) and to study the release mechanism of polysaccharide in suitable conditions with a goal of an efficiency time less than 600 seconds.Concentrated W/O emulsions were realized by using a rotor stator system at room temperature. Aqueous phase containing polysaccharide and glycerol was dispersed into the stirred oil continuous phase where in a surfactant (lecithin and/or polyglycerol polyricinoleate, PGPR) has been previously dissolved. Stability tests were performed immediately after preparation and after ageing tests. Various parameters having an influence on thestability have been interpreted from DSC thermogram parallel with microscopic observation, laser diffraction granulometry and rheology measurement. DSC technique was used to study the emulsions by following the evolution of the droplet size versus time. Thermal behaviour of emulsions may be evaluated when they under gofreezing and melting in which the proportion of ice formed in the droplets may be calculated and their link with the evolution of the emulsion versus time. The release of the polysaccharide (CarboxyMethyl Cellulose, CMC)from the emulsion system is obtained by a two steps process : destabilization of the primary W/O emulsion by achemical product and dilution in water that gives an O/W emulsion containing the required concentration of polysaccharide. Destabilization was observed by following the evolution of dispersed droplets using DSC. Dilution process was assessed by measuring electrical conductivity of the water solution and a mathematical model to represent the kinetic release of CMC in water was proposed.The formulation and the stability of concentrated W/O emulsion has shown that DSC completed with granulometry and rheometry is an appropriate technique to study the emulsion characteristics. The study offreezing behaviour of emulsions show that the proportion of ice formed in the dispersed droplets during DSC test indicates good agreement between DSC measurements and thermodynamics calculation. The use of PGPRas surfactant and the introduction of glycerol in the formulation are beneficial to improve the long‐term stabilityof the emulsion. The optimum formulation of concentrated W/O emulsion was obtained containing : 3.5% w/wof CMC, 10% w/w of glycerol in 75% v/v of dispersed phase and 14% w/w of PGPR in the continuous phase. From the release study, an empirical model may be used to describe the released kinetic. The optimum amount of nonionic surfactant Cynthiorex PMH 1125 to break primary W/O emulsion was found at 10% w/w in the primary emulsion with NRe ≥ 4200 and T ≥ 20°C. Under practical field conditions, the minimum release time isthen around 200 seconds

Ultrasonic Irradiation Coupled with Microwave Treatment for Eco-friendly Process of Isolating Bacterial Cellulose Nanocrystals

The isolation of crystalline regions from fibers cellulose via the hydrolysis route generally requires corrosive chemicals, high-energy demands, and long reaction times, resulting in high economic costs and environmental impact. From this basis, this work seeks to develop environment-friendly processes for the production of Bacterial Cellulose Nanocrystals (BC-NC). To overcome the aforementioned issues, this study proposes a fast, highly-efficient and eco-friendly method for the isolation of cellulose nanocrystals from Bacterial Cellulose, BC. A two-step processes is considered: (1) partial depolymerization of Bacterial Cellulose (DP-BC) under ultrasonic conditions; (2) extraction of crystalline regions (BC-NC) by treatment with diluted HCl catalyzed by metal chlorides (MnCl2 and FeCl3.6H2O) under microwave irradiation. The effect of ultrasonic time and reactant and catalyst concentrations on the index crystallinity (CrI), chemical structure, thermal properties, and surface morphology of DP-BC and BC-NC were evaluated. The results indicated that the ultrasonic treatment induced depolymerization of BC characterized by an increase of the CrI. The microwave assisted by MnCl2-catalyzed mild acid hydrolysis enhanced the removal of the amorphous regions, yielding BC-NC. A chemical structure analysis demonstrated that the chemical structures of DP-BC and BC-NC remained unchanged after the ultrasonic treatment and MnCl2-catalyzed acid hydrolysis process

Effect of Addition of Potassium Permanganate (KMnO4) on Shelf Life of Bananas Coated With Chitosan Based Coating

The most popular fruit is bananas. The problem bananas face declining quality or preservation of fruit before reaching the consumers. The decline in the quality of post-harvest bananas is generally caused by shrinkage of fruit mass and ripening caused by respiration and the presence of ethylene gas. One of the ways to prevent the decrease in the quality of bananas is by coating the fruit with Chitosan-based edible film. This study aims to determine the effect of adding ethylene absorber (KMnO4) to the coating Chitosan base and the composition of the coating film with the best performance in extending the shelf life of bananas. Edible film Nano Chitosan was synthesized from Sodium tripolyphosphate (TPP) and the addition of Cellulose nanocrystal (CNC) as a stabilizer agent to form a nano-composite to improve the mechanical properties of the edible coating. The method used is to provide a coating of Chitosan, and nano Chitosan with the addition of CNC and KMnO4 applied on bananas. The analysis results showed that the composition of Chitosan-CNC-KMnO4 gave the optimum performance in decline shrinkage of bananas mass with a weight loss value of 4.87% in 5th days had the lowest sugar content value on the 5th day, which was 16%.ABSTRAKBuah yang paling digemari masyarakat salah satunya adalah Pisang. Salah satu problem terkait buah pisang adalah penurunan kualitas atau pengawetan buah pisang sebelum sampai konsumen. Penurunan kualitas buah pisang pasca panen pada umumnya disebabkan oleh penyusutan massa buah dan pematangan sebelum waktunya yang diakibatkan respirasi dan adanya gas Ethylene. Penurunan kualitas buah pisang dapat dihambat dengan melapisi buah dengan coating berbasis Chitosan. Tujuan dari penelitian untuk mengetahui pengaruh penambahan Ethylene absorber (KMnO4)  pada coating film berbasiskan Chitosan serta komposisi coating film dengan performa terbaik dalam memperpanjang umur simpan buah pisang. Edible film Chitosan dan nano Chitosan disintesis dari Natrium Tripolyphospate (TPP) serta penambahan Celulose Nano Crystal (CNC) sebagai agen stabilizer sehingga terjadi keadaaan nano-komposit untuk meningkatkan properti mekanis dari edible coating. Metode yang digunakan dengan memberikan coating berbasis Chitosan dan berbasis nano Chitosan dengan penambahan CNC dan KMnO4 pada buah pisang. Hasil analisa menunjukkan bahwa coating dengan komposisi nano Chitosan-CNC-KMnO4 memberikan performa terbaik dalam menghambat penyusutan buah pisang dengan nilai susut bobot 4,87% Dan juga dalam menghambat pematangan, buah pisang memiliki nilai kadar gula terendah, yaitu sebesar 16%.

Fabrication of Polymer Matrix Composites by Bagasse based on Yukalac Polyester Resin

The natural fibre containing cellulose as its main component that can be used as an alternative material to improve the strength of polymer composites. Paper focused on the determination of the best volume fraction of sugarcane fibre-reinforced polymer composites. Three variants of alkalization time were carried out. The highest average value of the tensile test results was obtained at an alkalization time of 1.5 h with a tensile strength of 41 N mm−2 and elongation correspond to 11.806% where the highest bending test results were obtained at an alkalizing time of 0.5 h with a bending strength of 24.89 N mm−2. The results of mechanical interlocking have been observed on macrostructure photo and at 1.5 h of alkalization are better than 0.5 h and 1 h of alkalizing time

Nanofluid to Nanocomposite Film: Chitosan and Cellulose-Based Edible Packaging

Chitosan (CH)-based materials are compatible to form biocomposite film for food packaging applications. In order to enhance water resistance and mechanical properties, cellulose can be introduced to the chitosan-based film. In this work, we evaluate the morphology and water resistance of films prepared from chitosan and cellulose in their nanoscale form and study the phenomena underlying the film formation. Nanofluid properties are shown to be dependent on the particle form and drive the morphology of the prepared film. Film thickness and water resistance (in vapor or liquid phase) are clearly enhanced by the adjunction of nanocrystalline cellulose

Ultrasonic Irradiation Coupled with Microwave Treatment for Eco-friendly Process of Isolating Bacterial Cellulose Nanocrystals

International audienceThe isolation of crystalline regions from fibers cellulose via the hydrolysis route generally requires corrosive chemicals, high-energy demands, and long reaction times, resulting in high economic costs and environmental impact. From this basis, this work seeks to develop environment-friendly processes for the production of Bacterial Cellulose Nanocrystals (BC-NC). To overcome the aforementioned issues, this study proposes a fast, highly-efficient and eco-friendly method for the isolation of cellulose nanocrystals from Bacterial Cellulose, BC. A two-step processes is considered: (1) partial depolymerization of Bacterial Cellulose (DP-BC) under ultrasonic conditions; (2) extraction of crystalline regions (BC-NC) by treatment with diluted HCl catalyzed by metal chlorides (MnCl 2 and FeCl 3 .6H 2 O) under microwave irradiation. The effect of ultrasonic time and reactant and catalyst concentrations on the index crystallinity (CrI), chemical structure, thermal properties, and surface morphology of DP-BC and BC-NC were evaluated. The results indicated that the ultrasonic treatment induced depolymerization of BC characterized by an increase of the CrI. The microwave assisted by MnCl 2-catalyzed mild acid hydrolysis enhanced the removal of the amorphous regions, yielding BC-NC. A chemical structure analysis demonstrated that the chemical structures of DP-BC and BC-NC remained unchanged after the ultrasonic treatment and MnCl 2-catalyzed acid hydrolysis process

Cellulose Nanocrystals to Improve Stability and Functional Properties of Emulsified Film Based on Chitosan Nanoparticles and Beeswax

International audienceThe framework of this work was to develop an emulsion-based edible film based on a chitosan nanoparticle matrix with cellulose nanocrystals (CNCs) as a stabilizer and reinforcement filler. The chitosan nanoparticles were synthesized based on ionic cross-linking with sodium tripolyphosphate and glycerol as a plasticizer. The emulsified film was prepared through a combination system of Pickering emulsification and water evaporation. The oil-in-water emulsion was prepared by dispersing beeswax into an aqueous colloidal suspension of chitosan nanoparticles using high-speed homogenizer at room temperature. Various properties were characterized, including surface morphology, stability, water vapor barrier, mechanical properties, compatibility, and thermal behaviour. Experimental results established that CNCs and glycerol improve the homogeneity and stability of the beeswax dispersed droplets in the emulsion system which promotes the water-resistant properties but deteriorates the film strength at the same time. When incorporating 2.5% w/w CNCs, the tensile strength of the composite film reached the maximum value, 74.9 MPa, which was 32.5% higher than that of the pure chitosan film, while the optimum one was at 62.5 MPa, and was obtained by the addition of 25% w/w beeswax. All film characterizations demonstrated that the interaction between CNCs and chitosan molecules improved their physical and thermal properties