Description:Title of the Invention
BIODEGRADABLE PLASTIC FILM SYNTHESIS FROM RICE STRAW EXTRACTED CELLULOSE
Field of the invention
The current invention relates to biodegradable plastic film synthesis from rice straw extracted cellulose.
Background of the Invention
References which are cited in the present disclosure are not necessarily prior art and therefore their citation does not constitute an admission that such references are prior art in any jurisdiction. All publications, patents and patent applications herein are incorporated by reference to the same extent as if each individual or patent application was specifically and individually indicated to be incorporated by reference.
Several patents have been issued for biodegradable plastic film but none of these are related to the present invention which is biodegradable plastic film synthesis from rice straw extracted cellulose. For example, US11198767B2 provides to plastic composition comprising at least one polyester, biological entities having a polyester-degrading activity and at least an anti-acid filler, wherein the biological entities represent less than 11% by weight, based on the total weight of the plastic composition, and uses thereof for manufacturing biodegradable plastic articles.
Another patent, WO2016029024A1 concerns to a biodegradable, thermally insulated mailer and cooler, and method of making them, are disclosed. The thermally insulated packaging material are made from laminated starch foam and bio-plastic film. The lamination can be performed by heat bonding, without the use of an adhesive bonding agent, to produce biodegradable packaging materials that can pass ASTM and other certifications for home compostability and marine environment safety.
Another patent, US10433543B2 provides a multi-layer bioactive and biodegradable film. The multi-layer film includes one or more bioactive compounds or microorganisms for promoting growth and health of a plant, the bioactive compounds or microorganisms contained between layers of the film, wherein each one of the layers comprises about 60% to about 75% (m/m) polyhydroxyalkanoate. The bioactive compounds or microorganisms may include any one of or a combination of: a metabolite, an anti-microbial compound, an enzyme, a live microorganism, a fertilizer, a plant growth hormone, a preservative, a pesticide or an herbicide. Release of one or more bioactive compounds may be achieved in a timed and controlled manner.
Another patent, CN104098791B relates to a kind of biodegradable thermoplastic starch-polyethylene film, relate to thin film fabrication techniques field, be made up of the raw material of following mass fraction: thermoplastic starch (self-control) 40%-50%, polyethylene 20%-30%, Microcrystalline Cellulose 0.5%-3%, calcium sulfate 2%-5%, oxidized polyethlene wax 1%-3%, Zinic stearas 1%-2%, polyhydroxyalkanoate 1%-2.5%, ethylene glycol 0.5%-2%, sorbyl alcohol 0.5%-2%, maleic anhydride 0.5%-3%, glutaraldehyde 0.2%-1%.Thermoplastic starch-polyethylene film prepared by the present invention not only has good mechanical property, also there is excellent biodegradability, the use range of product is wide, and can make multiple plastics on market, be a kind of biodegradable plastic film with broad mass market prospect.
Another patent, CN112175330A provides a completely biodegradable plastic film prepared from straws and a preparation method thereof, relates to the technical field of straw resource utilization in agricultural wastes, solves the problem of higher technical cost of the existing technology for preparing completely biodegradable materials from biodegradable polymers, and is prepared from the following raw materials in parts by weight: 50-90 parts of biodegradable polymer, 10-40 parts of straw, 0.5-2 parts of surface modifier, 5-10 parts of plasticizing modifier, 5-10 parts of film forming agent and 0.2-1 part of nano silver. The method for preparing the completely biodegradable material by using the straw to replace partial biodegradable polymer effectively reduces the cost of technical raw materials, and achieves the effects of resource saving, environmental protection, wide raw material source, simple process, easy realization of industrialization and the like.
Another patent, CN109824924A provides a kind of packaging films and preparation method thereof that can be degradable, this method is using straw, and starch and degradation plastic material are raw material, is made by following steps:
(1) by crushing to straw, alkali process, defibrination process obtain plant straw fibers slurry;
(2) by modified to food starch, obtained thermoplastic starch
(3) above-mentioned plant straw fibers slurry and thermoplastic starch are blended with degradation plastic material, high temperature plasticizing.
The beneficial effect is that packaging film of the invention can be degradable in nature, not can cause environmental pollution. Film component is safe and non-toxic, can be used for food packaging. The excellent in mechanical performance such as tensile strength, the elongation at break of film. Raw material sources are abundant, and production cost is low, enriches the resource utilization of stalk. Simple production process is controllable, and stability is good, is suitble to large-scale industrial production.
Another patent US5346929A relates to a biodegradable plastic made from a combination of at least one synthetic plastic polymer, at least one natural polymer and a natural polymer attacking agent and articles made therefrom.
Processing of agro waste for value addition or production of value-added products is identified as optimum approach for waste management and acquire economic benefit (through application of value-added product) with simultaneous substantial contribution towards environmental sustainability. Rice straw is among the major agro waste generated in huge volumes across the world. Management of which is a global challenge since a major portion of rice straw is either burned or dumped in open files in both the cases posing a threat to environment sustainability. The present invention reports an environment friendly process for cellulose extraction from rice straw which not only results in production of value-added product but also provides a suitable alternate for rice straw waste management. Scaling up of the process at industrial level will minimize the dumping of rice straw waste into the ecosystem. In addition to management of rice straw waste the present invention also addresses the challenge to minimize utilization of non-biodegradable plastic. Analytical characterization and assessment of natural degradability of the bioplastic film synthesized (in present work) justifies its processing and utilization as an alternate to non-biodegradable plastic films.
ADVANTAGES OF THE INVENTION:
The major advantage of the present invention is summarized as follows:
Utilization of rice straw waste as raw material which will limit the dumping of rice straw waste in ecosystem and also prevent the burring of rice straw by local state holders the get rid of huge volumes of rice straw waste generated.
Process reported for cellulose extraction is environment friendly as it utilizes less chemicals compared to earlier reported methods of cellulose extraction.
Also, the method reported for cellulose extraction is less time-consuming compared to earlier reported methods of cellulose extraction.
The bioplastic film synthesized is biodegradable an exhibits property which supports its commercial utilization.
The reported methods are easily reproducible (How to Make and How to Use).
The primary object of the present invention is biodegradable plastic film synthesis from rice straw extracted cellulose.
Another object of the present invention is to synthesis of plastic film from rice straw extracted cellulose.
Another object of the present invention is to synthesis of biodegradable plastic film from cellulose extracted from rice straw.
These and other objects and advantages of the present invention will become readily apparent from the following detailed description.
Summary of Invention
This summary is not a comprehensive overview of the disclosure and does not reflect the main/essential features of the establishment or specify the scope of the establishment. Its sole purpose is to present some of the concepts presented here in a simpler way as a precursor to more detailed explanations presented later.
The present invention relates to biodegradable plastic film synthesis from rice straw extracted cellulose.
In some embodiments of the present invention, rice straw was cut in small pieces and grinded and finally sieved (150 microns). The sieved powder was finally used as feedstock for the extraction of cellulose and utilization of cellulose for the bioplastic film preparation.
In some embodiments of the present invention, a handheld vernier caliper (least count 0.01 mm, measuring range 0-130mm) was used for measuring the thickness of the bioplastic films. The bioplastic films produced were cut into 2 cm?×?2 cm dimension for testing. At random positions, the thickness of each film samples measured and values were noted. The mean values of thickness were used in the further tests.
In some embodiments of the present invention, the bioplastic films were cut into 1 cm × 3 cm in order to match the width and height of cuvette. The films were attached to the side of the cuvette. Synthetic plastic film made from polyvinyl alcohol was used as control. Absorbance was recorded at 600 nm.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in concurrence with the following explanation and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
Brief summary of the drawings
Fig.1: Stepwise process followed for cellulose extraction and bioplastic film preparation.
Fig.2: Outline of process optimized for extraction of cellulose from rice straw waste.
Fig.3: Stepwise process of bioplastic film synthesis.
Fig 4: FTIR analysis of extracted cellulose.
Fig. 5: XRD analysis of extracted cellulose.
Fig. 6: SEM analysis of extracted cellulose.
Fig7: SEM analysis of synthesized Bioplastic films.
Fig 8: Bioplastic film synthesized at different compositions of cellulose and PVA.
Fig 9: Degradation of synthesized bioplastic film by natural microflora of soil collected from Uttaranchal university, Dehradun.
Brief summary of the tables
Table 1: Composition of different bioplastic film synthesized.
Table 2. SEM analysis of synthesized bioplastic films.
Table 3: Physiological properties of Bioplastic films.
Table 4: Transparency analysis synthesized Bioplastic films.
DETAILED DESCRIPTION OF THE INVENTION
These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
The present invention relates to relates biodegradable plastic film synthesis from rice straw extracted cellulose.
In some embodiments of the present invention, rice straw was collected and stored in air tight container. Rice straw was cut in small pieces and grinded and finally sieved (150 microns). The sieved powder was finally used as feedstock for the extraction of cellulose and utilization of cellulose for the bioplastic film preparation.
In some embodiments of the present invention, a handheld Vernier caliper (least count 0.01 mm, measuring range 0-130mm) was used for measuring the thickness of the bioplastic films. The bioplastic films produced were cut into 2 cm?×?2 cm dimension for testing. At random positions, the thickness of each film samples measured and values were noted. The mean values of thickness were used in the further tests.
In some embodiments of the present invention, the bioplastic films were cut into 1 cm × 3 cm in order to match the width and height of cuvette. The films were attached to the side of the cuvette. Synthetic plastic film made from polyvinyl alcohol was used as control. Absorbance was recorded at 600 nm. Transmittance was calculated using below mentioned equation.
In some embodiments of the present invention, the synthesized bioplastic films were subjected to assess their natural biodegradability through soil burial biodegradation test. For the test soil from campus of Uttaranchal university was collected and transferred to garden pots. The pots were labelled accordingly.
In some embodiments of the present invention, in each pot (six in number) a bioplastic film was buried to a depth of 5cm and completely covered with soil. The pots were placed at room temperature and left undisturbed. At an interval of every 15 days the bioplastic films were monitored to observe the degree of degradation. The weight of bioplastic film and visual observation were recorded to assess the extent of degradation.
In some embodiments of the present invention, the rectangular strip of bioplastic film was clamped from both ends and mounted on the Instron machine. This machine was adjusted to move at a uniform crosshead speed of 10 mm/min. The movement was continued till tear commenced and was retained. The force required to commence the tear was recorded.
A biodegradable plastic film synthesis,
wherein;
used rice straw as cellulose source, Polyvinyl alcohol (PVA), NaOH, NaOCl and water as solvent.
A method of synthesis of the biodegradable plastic films as claimed in claim 1, wherein the method comprising the steps of: -
heating rice straw powder in water (200 ml) at 50 oC for 2 hours with constant string;
filtering and washing with distilled water, collecting the residue;
adding 200 ml of NaOH, heated at 55 oC for 1.5 hours with constant string;
after filtering and washing adding 200 ml of NaOCl;
heating the mixture at 70 oC for 1 hour with constant string;
adding 100 ml of H2O2 after filtering and washing, heated at 70 oC for 30 min with constant string;
finally filtering and washing with distilled water, and collecting the residue;
drying the collected cellulose in oven at 50 oC for 1 hour;
heating PVA in 20 ml of water at 60 oC for 20 min with constant string on a hot plate with magnetic stirrer;
adding the cellulose extracted from rice straw for 20 min with constant stirring on a hot plate with magnetic stirrer; and
pouring into petridish, drying at RT for overnight, and collected carefully.
The method as claimed in claim 2, wherein the best composition optimized of cellulose and Polyvinyl alcohol is 0.8:0.2 ratio for the synthesis of bioplastic film.
The method as claimed in claim 2, wherein 5% NaOH and 5% NaOCl is used for the extracting the cellulose from the rice straw.

EXAMPLE 1
METHOD
Collection of feedstock
Rice straw was collected from Miragpur, Saharanpur, Uttar Pradesh, India (Latitude- 77°45’33.4” E Longitude- 29°40’55.9” N) and stored in air tight container and transported to Biotechnology laboratory, School of Applied and Life Sciences, Uttaranchal University, Dehradun. Rice straw was cut in small pieces and grinded and finally sieved (150 microns). The sieved powder was finally used as feedstock for the extraction of cellulose and utilization of cellulose for the bioplastic film preparation (Table 1).
Synthesized bioplastic film from cellulose extracted by rice straw
Cellulose was successfully extracted from dried rice straw powder. Figure 1-3 illustrates the stepwise stages for extraction of cellulose. The brown color of rice straw reduced in each stage of delignification to become pure white which is referred as cellulose. On an average 27 gm of cellulose was extracted from 50 gm of rice straw.
Table 1: Composition of different bioplastic film synthesized.
Composition of bioplastic film Designated code
0.2gm Cellulose + 0.8gm PVA Bioplastic film-1
0.4gm Cellulose + 0.6gm PVA Bioplastic film-2
0.6gm Cellulose + 0.4gm PVA Bioplastic film-3
0.8gm Cellulose + 0.2gm PVA Bioplastic film-4
0.5gm Cellulose + 0.5gm PVA Bioplastic film-5
1gm PVA Bioplastic film-6

Analysis of Cellulose and Bioplastic film
Bioplastic film thickness
A handheld Vernier calliper (least count 0.01 mm, measuring range 0-130mm) was used for measuring the thickness of the bioplastic films. The bioplastic films produced were cut into 2 cm?×?2 cm dimension for testing. At random positions, the thickness of each film samples measured and values were noted. The mean values of thickness were used in the further tests.
Bioplastic film transparency
Film transparency of the film samples was determined with minor modification. The bioplastic films were cut into 1 cm × 3 cm in order to match the width and height of cuvette. The films were attached to the side of the cuvette. Synthetic plastic film made from polyvinyl alcohol was used as control. Absorbance was recorded at 600 nm. Transmittance was calculated using below mentioned equation.
%T=antilog (2-absorbance)
The transparency was determined using the formula,
Transparency=(Log%T)/b
%T is transmittance at 600 nm and b is the thickness of bioplastic (mm).
Natural degradability of bioplastic films
The synthesized bioplastic films were subjected to assess their natural biodegradability through soil burial biodegradation test. For the test soil from campus of Uttaranchal university was collected and transferred to garden pots. The pots were labelled accordingly. (Figure 9) in each pot (six in number) a bioplastic film was buried to a depth of 5cm and completely covered with soil. The pots were placed at room temperature and left undisturbed. At an interval of every 15 days the bioplastic films were monitored to observe the degree of degradation. The weight of bioplastic film and visual observation were recorded to assess the extent of degradation.
Tear strength determination
The rectangular strip of bioplastic film was clamped from both ends and mounted on the Instron machine. This machine was adjusted to move at a uniform crosshead speed of 10 mm/min. The movement was continued till tear commenced and was retained. The force required to commence the tear was recorded.
Tear strength is calculated as:
Tear strength=Force/Thickness
Grams per square meter:
It is calculated as:
Grams per square meter (gm/m2) = weight of sample in gm × 1000 / Area of sample in cm2
EXAMPLE 2
RESULTS AND DISCUSSION:
FTIR analysis of extracted cellulose from rice straw
FTIR analysis of cellulose depicts peaks corresponding to diverse functional groups/organic compounds (Figure 4). Respective wavelength on which peaks were obtained were utilized to identify the functional group to which a particular peak belongs by the similar data reported in literatures. Interpretation of FTIR data depict weak hydroxyl compounds bonding at 3338 cm-1, C-H stretching at 2898 cm-1 sharp peak and high transmittance, C=C stretching at 2134 cm-1 broad peak and low transmittance. Since pure cellulose has a considerable affinity for water, the absorption at 1635 cm-1 is mostly related to the water that has been adsorbed but sharp peak and high transmittance. C-H2 symmetric bending at 1429 cm-1 sharp peak but low transmittance, C-H bending at 1374 cm-1 sharp peak but low transmittance, C-O anti-symmetric stretching at 1162 cm-1 sharp peak but low transmittance, C-O-C pyranose ring skeletal vibration at 1059 cm-1 sharp peak but low transmittance. The peak at 895 cm-1 indicates the glycosidic C-H deformation with ring vibration contribution and OH bending but sharp peak with low transmittance. C-Br stretching at 668 cm-1 sharp peak but transmittance is very low and C-I stretching at 611 cm-1 sharp peak but transmittance is very low.
XRD analysis of extracted cellulose from rice straw
XRD analysis was conducted for identification of crystal and amorphous arrangement of cellulose. The diffraction patterns cellulose extracted from rice straw is shown in Figure 5. From the figure it can be clearly seen peaks for cellulose are obtained at 22.69º, 16.28º. Appearance of low intensity broad peak confirms amorphous nature of cellulose (JCPDS card no. 03-0289).
Scanning Electron Microscopy (SEM) analysis
(A) SEM analysis of extracted cellulose from rice straw
Scanning electron microscopy (SEM) images were used to investigate the surface morphology of the cellulose. As it is seen in Figure 6, distribution of the cellulose particles on the different magnification. Figure 6 (A) shown structure wire like bunched and uniform distribution in 500x magnification, 50µm range of area and select an area of bunched particle seen in Figure 6 (B) higher magnification range 2000x, 10µm the wire like particles is separately distributed.
(B) SEM analysis of Bioplastic film
Scanning electron microscopy (SEM) images were also used to investigate the surface morphology of the bioplastic film (Figure 7).
Table 2: SEM analysis of synthesized bioplastic films.
Bioplastic film 5000x 10000x
1 (A, B) Agglutinated particles smooth surface Agglutinated particle and uniform distribution
2 (C, D) Agglutinated particles smooth surface Agglutinated and uniform distribution but some particles was seen in clumped form distribution
3 (E, F) Agglutinated particles smooth surface Particles are agglutinated and uniform distribution but some particles was seen in clumped and spherical, rod like form distribution
4 (G, H) Agglutinated particles rough surface Agglutinated and uniform distribution but some particles was seen in clumped and spherical form distribution
5 (I, J) Agglutinated particles smooth surface Agglutinated particles and uniform distribution
6 (K, L) Agglutinated particles smooth surface Agglutinated particles and uniform distribution

Cellulose extracted from rice straw is finally utilized for producing fibrous structural constituent of bioplastic film. It generates a mechanically strong biological film with high tear and tensile strength. Synthesized bioplastic film is shown in Figure 8. Its physiological properties are given in Table 3. Additionally, cellulose-based bioplastic film is biocompatible and can be used for packaging purposes.
Six different types of bioplastic films are synthesized based on different concentration of cellulose and PVA. Tear strength of bioplastic film-4 has found to be more as compared to the other bioplastic films. The range of tear strength is found as bioplastic film-4> bioplastic film-2> bioplastic film-3> bioplastic film-5> bioplastic film-1>bioplastic film-6 as mentioned in Table 3. Therefore, based on the tear strengths, optimized composition of cellulose and PVA for the synthesis of bioplastic film is found to be 0.8 gm and 0.2 gm. The thickness of bioplastic film-4 is found to be less as compared to the other bioplastic films. Therefore, based on the thickness of bioplastic films, GSM obtained of bioplastic film-4 is also less as compared to the other bioplastic films as shown in Table 3.
Table 3: Physiological properties of Bioplastic films.
S. No. Bioplastic film ratio Thickness (mm) Grams per square meter (gm/m2) Force (N) Tear strength (N/mm)
1. Bioplastic film-1 0.3 10.73
38.44 128.133
2. Bioplastic film-2 0.2 8.31
43.93 219.65
3. Bioplastic film-3 0.3 9.84
47.22 157.4
4. Bioplastic film-4 0.2 8.86
53.82 269.1
5. Bioplastic film-5 0.3 8.22 46.36 154.5
6. Bioplastic film-6 0.3 12.35 28.56 95.2

Bioplastic film transparency
Table 4: Transparency analysis synthesized Bioplastic films.
Bioplastic film Thickness (mm) Absorbance Transmission% Transparency
Bioplastic film-1 0.3 0.360 43.65 5.47
Bioplastic film-2 0.2 0.398 39.99 8.01
Bioplastic film-3 0.3 0.414 38.55 5.29
Bioplastic film-4 0.2 0.443 36.06 7.78
Bioplastic film-5 0.3 0.402 39.63 5.33
Bioplastic film-6 0.3 0.166 68.23 6.11

Different types of bioplastic films were synthesized based on different concentration of Cellulose and PVA. As shown in Table 3, composition of 0.8gm Cellulose & 0.2gm PVA was found to be the optimized ratio for the synthesis of bioplastic film in which maximum value of force 53.82 N and tear strength of 269 N/mm was obtained. The tear and tensile strength of bioplastic film produced by this composition is significantly higher than the other composition ratio of Cellulose and PVA. Moreover, the transparency of bioplastic film produced by the same ratio is on the upper side as compared to the transparency produced by bioplastic film generated from other compositions.
Degradation of bioplastic films by natural microflora of soil
All the six bioplastic films synthesize were evaluated to assess their natural biodegradability potential (Figure 9). Soil collected from Uttaranchal university, Dehradun campus was collected and each fil was separately incubated in soil. All bioplastic films depicted natural degradation ability with bioplastic film 2, 3 and 4 exhibiting 100% degradation after 30 days of incubation.
, Claims:
1. A biodegradable plastic film synthesis,
wherein;
used rice straw as cellulose source, Polyvinyl alcohol (PVA), NaOH, NaOCl and water as solvent.
2. A method of synthesis of the biodegradable plastic films as claimed in claim 1, wherein the method comprising the steps of: -
a. heating rice straw powder in water (200 ml) at 50 oC for 2 hours with constant string;
b. filtering and washing with distilled water, collecting the residue;
c. adding 200 ml of NaOH, heated at 55 oC for 1.5 hours with constant string;
d. after filtering and washing adding 200 ml of NaOCl;
e. heating the mixture at 70 oC for 1 hour with constant string;
f. adding 100 ml of H2O2 after filtering and washing, heated at 70 oC for 30 min with constant string;
g. finally filtering and washing with distilled water, and collecting the residue;
h. drying the collected cellulose in oven at 50 oC for 1 hour;
i. heating PVA in 20 ml of water at 60 oC for 20 min with constant string on a hot plate with magnetic stirrer;
j. adding the cellulose extracted from rice straw for 20 min with constant stirring on a hot plate with magnetic stirrer; and
k. pouring into petridish, drying at RT for overnight, and collected carefully.
3. The method as claimed in claim 2, wherein the best composition optimized of cellulose and Polyvinyl alcohol is 0.8:0.2 ratio for the synthesis of bioplastic film.
4. The method as claimed in claim 2, wherein 5% NaOH and 5% NaOCl is used for the extracting the cellulose from the rice straw.