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1. WO2020115619 - COMPOSITION DE BIOPLASTIQUE ET PROCÉDÉ DE PRÉPARATION D'UN FILM BIOPLASTIQUE

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

COMPOSITION OF A BIOPLASTIC AND PROCESS FOR PREPARATION OF A

BIOPLASTIC FILM

FIELD OF INVENTION

[001] Embodiments of a present disclosure relate to plastic chemical composition and, more particularly to composition of a bioplastic and process for preparation of a bioplastic film.

BACKGROUND

[002] The benefits of plastics are unmatched when we compare plastics with any other material used by us for making different types of packets and bags, packaging, insulating, and making moulded articles. The plastics are light weight, inert to organic solvents and most of inorganic solvents, inexpensive, strong, and easily shaped.

[003] A conventional plastic is prepared from oil, natural gas, or coal. The production of the conventional plastic from the conventional sources result in release of poisonous chemicals. Such poisonous chemicals create diseases which relates to brain, breast, prostate, reproductive and immune system. Moreover, the conventional plastics are not eco-friendly because the conventional plastics are not bio degradable in natural state. The huge mountains of conventional plastics accumulated as urban waste are causing plethora of problems to nature and living beings alike. For this very reason, many governments across the world have banned the use of plastics by common public to minimise the damage.

[004] As a viable alternative to the conventional plastics the research is ongoing to develop bioplastics. The recently developed bioplastics are produced from natural materials like corn starch, polylactic acid (PLA), which are designed to degrade quickly without leaching any chemicals into earth. However, the bioplastics release methane gas during the decomposition, where the methane being a greenhouse gas adds to another set of environmental problems such as global warming and air pollution. There is need for a commercial composting facility to handle above mentioned release of toxic gases, but this such installation and maintenance facilities and management of toxic gases lead to high cost of operation. Therefore, the bioplastics so produced cannot be easily recycled and has a pollution footprint.

[005] Further, the bioplastics also face the issues with characteristics of plastic products like tensile strength, elongation, and water vapor permeability. For this reason, the present state of art has failed to produce bioplastics in an efficient manner having desired characteristics.

[006] Hence, there is a need for an improved composition of a bioplastic and process for preparation thereof to addresses the aforementioned issues.

SUMMARY OF THE INVENTION

[007] In accordance with one embodiment of the disclosure, a composition of a bioplastic and process for preparation is provided. In one embodiment, the composition includes 4 to 10 percentage of weight of agarose, 50 to 70 percentage weight of plasticizer to weight of the agarose, 3 to 10 percentage weight of silicon dioxide (Si02) to weight of the plasticizer and 3 to 10 percentage weight sodium dodecyl sulphate (SDS) to the weight of plasticizer. The agarose, the plasticizer, the silicon dioxide (Si02) and the SDS are dissolved in water.

[008] In one specific embodiment, the composition includes 6 percentage weight of agarose, 62.5 percentage of plasticizer to weight of the agarose, 6 percentage weight of silicon dioxide (Si02) to the weight of plasticizer, and 6 percentage weight sodium dodecyl sulphate (SDS) to the weight of plasticizer.

[009] In accordance with another embodiment of the disclosure, a process for preparation of a bioplastic film is provided. The process includes mixing a bioplastic composition with water. The process also includes heating the mixture of the bioplastic composition with water at 90 degree Celsius to 100 degree Celsius for obtaining a molten state of the bioplastic composition. The process also includes mixing Sodium Dodecyl Sulphate (SDS) to the molten state of the mixture of the bioplastic composition. The process also includes spreading a mixture of molten

bioplastic composition obtained in mixing, on a flat surface to obtain the bioplastic

film.

[0010] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:

[0011] FIG. 1 illustrates a representative image of agarose-based bioplastic sheet in accordance with an embodiment of the present disclosure;

[0012] FIG. 2Aillustrates an image of degradation study under decomposed humus soil on first day in accordance with an embodiment of the present disclosure;

[0013] FIG. 2B illustrates an image of degradation study under decomposed humus soil after 45 days in accordance with an embodiment of the present disclosure;

[0014] FIG. 3 A illustrates characterization of a bioplastic sheet through Scanning Electron Microscope (SEM) in accordance with an embodiment of the present disclosure;

[0015] FIG. 3B illustrates characterization of the bioplastic sheet through Energy Dispersive X-Ray Spectroscopy (EDS) in accordance with an embodiment of the present disclosure;

[0016] FIG. 4A illustrates a thermogravimetric analysis conducted for a first replicate bioplastic sheet replicate in accordance with an embodiment of the present disclosure;

[0017] FIG. 4B illustrates a thermogravimetric analysis conducted for a second replicate bioplastic sheet in accordance with an embodiment of the present disclosure;

[0018] FIG. 5 illustrates a swelling curve of the bioplastic sheet at normal room temperature of 25 °C as the function of time in minutes in accordance with an embodiment of the present disclosure;

[0019] FIG. 6 illustrates a water vapor permeability of the bioplastic sheet at room temperature of 25 °C with 80% relative humidity as the function of time in hours in accordance with an embodiment of the present disclosure; and

[0020] FIG. 7 is a flow diagram representing steps involved in a process (10) for preparation of a bioplastic film in accordance with an embodiment of the present disclosure.

[0021] Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. The Figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE INVENTION

[0022] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.

[0023] The terms "comprise", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, any element or composition or compound preceded by "comprises... a" does not, without more constraints, preclude the existence of other elements, composition, and compounds. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The product, methods, and examples provided herein are only illustrative and not intended to be limiting.

[0025] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms“a”,“an”, and “the” include plural references unless the context clearly dictates otherwise.

[0026] Embodiments of the present disclosure relate to a composition of a bioplastic and a process of preparation of a bioplastic film.

[0027] In an embodiment of the present disclosure, a composition of a bioplastic is provided. The composition of bioplastic includes 4 to 10 percentage of weight of agarose. The composition also includes 50 to 70 percentage weight of plasticizer to weight of the agarose. The composition also includes 3 to 10 percentage weight of silicon dioxide (Si02) to weight of the plasticizer. The composition also includes 3 to 10 percentage weight sodium dodecyl sulphate (SDS) to the weight of plasticizer.

The agarose, the plasticizer, the silicon dioxide (Si02) and the SDS dissolved in 80

to 95 percentage of water.

[0028] In one specific embodiment of the composition of the bioplastic, the composition includes6 percentage weight of agarose, 62.5 percentage of plasticizer to weight of the agarose, 6 percentage weight of silicon dioxide (Si02) to the weight of plasticizer, and 6 percentage weight sodium dodecyl sulphate (SDS) to the weight of plasticizer.

[0029] In an embodiment of the composition of the bioplastic, weight of agarose may be 6 grams, weight of the plasticizer may be 3.75 grams, weight of the silicon dioxide (Si02) may be 0.225 grams. The agarose, the plasticizer, and the silicon dioxide (Si02) are dissolved in 100 ml of water to obtain a mixture. Further, 0.225 grams of the sodium dodecyl is also added to the mixture.

[0030] The agarose used herein is a polysaccharide, generally extracted from certain red seaweed. Agarose is a linear polymer made up of the repeating unit of anaerobioses, which is a disaccharide made up of D-galactose and 3, 6-anhydro-Lgalactopyranose. Agarose is one of the two principal components of agar and is purified from agar by removing agar's other component, agaropectin.

[0031] The plasticizer provides the properties of plasticity and elasticity. In an embodiment, the plasticizer is a Polyethylene Glycol (PEG).

[0032] The silicon dioxide (Si02) is mixed with agarose and the plasticizer to increase the properties of hydrophobicity and strength. The silicon dioxide (Si02) is also known as silica, silicic acid or silicic acid anhydride which is an oxide of silicon.

[0033] The bioplastic compositions are dissolved in water. The bioplastic compositions are heated up to a boiling point to form a molten state. The molten state plastic spreading on the flat surface to form thin film. High surface tension of the bioplastic composition at molten state opposes spreading action on a flat surface. The Sodium Dodecyl Sulphate (SDS) is mixed with the bioplastic composition to reduce the surface tension of the bioplastic composition and thereby enables easy spreading of the molten state bioplastic on the flat surface. Size of the flat surface selected corresponds to the size of the bioplastic film required. For example, the flat surface may be a square where each side are 1 foot long.

[0034] The bioplastic is 100% bio-degradable in natural environment, and equally strong and versatile as the conventional plastics. The bioplastic is hydrophobic in nature of 80 percentage to 90 percentage at varying room atmospheric moisture conditions. The bioplastic is hydrophilic in nature of 10 percentage to 18 percentage at room atmospheric moisture condition.

[0035] FIG. 1 illustrates are presentative image of agarose-based bioplastic sheet in accordance with an embodiment of the present disclosure. The bioplastic sheet made up of includes agarose, plasticizer, silicon dioxide (Si02), and sodium dodecyl sulphate (SDS).

[0036] FIG. 2Aillustrates an image of degradation study under decomposed humus soil on first day in accordance with an embodiment of the present disclosure. The degradation study was performed under well decomposed humus soil. Triplicates of the agarose-based bioplastic sheet prepared were cut into size of 4 square centimetres each and placed under the humus. The humus moisture maintained regularly by adding water when the humus soil surface observed to be dry in condition. The FIG. 2A depicts various stages of degradation as observed during the study.

[0037] FIG. 2B illustrates an image of degradation study under decomposed humus soil after 45 days in accordance with an embodiment of the present disclosure. The degradation study

performed under well decomposed humus soil. Triplicates of the agarose-based bioplastic sheet prepared were cut into size of 4 square centimetres each and placed under the humus soil. The humus oil moisture was maintained regularly by adding water when the humus soil surface observed to be dry in condition. The FIG. 2B depicts various stages of degradation as observed during the study. Readings of percent reduction in weight observed on 12th day, 25thday and 45th day of the experiment. At the end of the 45th day an average of 46 percentage of reduction in weight was observed.

[0038] FIG. 3 A illustrates characterization of a bioplastic sheet through Scanning Electron Microscope (SEM) in accordance with an embodiment of the present disclosure. The bioplastic samples dried for three days by placing the bioplastics with anhydrous silica gel in a vacuum desiccator. The films were coated with a layer of gold through sputtering before characterization.

[0039] FIG. 3B illustrates characterization of the bioplastic sheet through Energy Dispersive X-Ray Spectroscopy (EDS) in accordance with an embodiment of the present disclosure. The Energy Dispersive X-Ray Spectroscopy (EDS) was done at an accelerating voltage of 20 kV.

[0040] FIG. 4A illustrates a thermogravimetric analysis conducted for a first replicate bioplastic sheet replicate in accordance with an embodiment of the present disclosure. The bioplastic sheets dried for three days in a vacuum desiccator lined with anhydrous silica gel. The first replicate bioplastic sheet with 10 mg and the TGA performed in an inert atmosphere of nitrogen gas with a purge rate of 100 milli litre per minute, with temperatures rising from ambient conditions to 600°C at the rate of 10°C/minute. Thermogravimetric analysis revealed that an average of 86.24% thermal decomposition was observed at 600 degree centigrade.

[0041] FIG. 4B illustrates a thermogravimetric analysis conducted for a second replicate bioplastic sheet in accordance with an embodiment of the present disclosure. The bioplastic sheets dried for three days in a vacuum desiccator lined with anhydrous silica gel. The second replicate bioplastic sheet with 10 mg and the TGA performed in an inert atmosphere of nitrogen gas with a purge rate of 100 milli litre per minute, with temperatures rising from ambient conditions to 600°C at the rate of 10°C/minute. Thermogravimetric analysis revealed that an average of 86.24% thermal decomposition was observed at 600 degree centigrade.

[0042] FIG. 5 illustrates a swelling curve of the bioplastic sheet at normal room temperature of 25 °C as the function of time in minutes in accordance with an embodiment of the present disclosure. Swelling behaviour of bioplastic sheet was studied as follows: Triplicates of the bioplastic sheet of size 4 square centimetres were cut and weighed and then all the samples were immersed in water. After every 15 minutes, the samples were taken out of the water, wiped with tissue paper to remove excess water on the surface, weighed and then placed back into the water to continue the study. The swelling studies of the agarose-based bioplastic sheets in water were performed for up to 120 minutes at the normal room temperatures of 25 °C.

[0043] The percentage of swelling (%S), defined by the equation:

%S = Weight gained after swelling - initial weight X100 Initial weight

[0044] It was observed that the rate of absorption of water was highest in the beginning and the amount of water absorption gradually decreased with time, as the sheets became saturated. The saturation was complete in 90 minutes. The amount of water absorbed was around 270% of the initial weight of the bioplastic sheet. To mention, within fifteen minutes of experiment significant swelling of bioplastic sheet was observed.

[0045] FIG. 6 illustrates a water vapor permeability of the bioplastic sheet at room temperature of 25 °C with 80 % relative humidity as the function of time in hours in accordance with an embodiment of the present disclosure. The biodegradability of bioplastic is due in part to its hygroscopic nature. The absorbance of water from the surrounding air makes a good environment for degradation of bioplastic. The water vapor permeability into bioplastic sheet is clearly dependent upon the relative humidity of the environment.

[0046] The effect of relative humidity on bioplastic sheet has been investigated as follows: Triplicates of the bioplastic sheet of size 4 square centimetres was cut and weighted accurately, and then all the samples were placed in the humidity chamber at the relative humidity of 80% and temperature of 25°C for 24 hours. The weight of the samples was weighed for every 2 hours and the readings are noted to calculate the weight gain and percentage of uptake. In the beginning, gradual increase in the rate of water vapor permeability was observed and at 14 to 16 hours of the experiment, the bioplastic sheets attained saturation with 275% of weight gain than that of the initial weight.

[0047] FIG. 7 is a flow diagram representing steps involved in a process (100) for preparation of a bioplastic film in accordance with an embodiment of the present disclosure. The process (100) includes mixing a bioplastic composition with water in step 110. In one embodiment, the bioplastic composition includes 4 to 10 percentage weight of agarose, 50 to 70 percentage weight of plasticizer to weight of agarose, 3 to 10 percentage weight of Silicon Dioxide (Si02) to weight of plasticizer, and 3 to 10 percentage weight sodium dodecyl sulphate (SDS) to the weight of the plasticizer. In another embodiment, the plasticizer is a Polyethylene Glycol (PEG).

[0048] The process (100) includes heating the mixture of the bioplastic composition with water at 90 degree Celsius to 100 degree Celsius for obtaining a molten state of the bioplastic composition in step 120.

[0049] The process (100) includes mixing Sodium Dodecyl Sulphate (SDS) to the molten state of the mixture of the bioplastic composition to reduce surface tension in step 130. In one embodiment, 3 to 10 percentage weight Sodium Dodecyl Sulphate (SDS) is mixed to the molten state of the mixture of the bioplastic composition. High surface tension of the bioplastic composition at molten state, opposes spreading action on a flat surface. The Sodium Dodecyl Sulphate (SDS) is mixed with the bioplastic composition to reduce the surface tension of the bioplastic composition and facilitate easy spreading of the molten state bioplastic on the flat surface.

[0050] The process also includes (10) spreading mixture of molten bioplastic composition obtained in step 130(mixing) on a flat surface to obtain the bioplastic film in step 140.

[0051] The obtained thin bioplastic film is dried at 60 degree Celsius in a closed chamber for pre-defined duration. In an embodiment the predefined duration is 18 hours.

[0052] Various embodiments of the present disclosure disclose the composition of a bioplastic. Also, the present composition provides eco-friendly and 100 percentage bio-degradable plastics. In addition, the present composition of the bioplastics will not release toxic gases during the decomposition so that no need for a commercial composting facility to avoid toxic gases. This present invention may solve the nuisance caused by conventional plastics in an effective way. [0053] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

[0054] The figures and the foregoing description give examples of embodiments. Order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependant on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.