GB2592855A

GB2592855A - Two-dimensional materials-based recycled polymer composite materials and method of preparation

Info

Publication number: GB2592855A
Application number: GB1914412.0A
Authority: GB
Inventors: Afroj Shaila
Original assignee: 2dtronics Ltd
Current assignee: 2dtronics Ltd
Priority date: 2019-10-06
Filing date: 2019-10-06
Publication date: 2021-09-15
Also published as: GB201914412D0

Abstract

A composite of graphene or other two-dimensional materials and recycled polymers and the method of preparing such composites, comprising graphene, it’s derivatives, or Molybdenum disulphide, Boron Nitride or Tungsten dichalcogenides mixed with recycled polymers such as polycarbonate, polyethylene or terephthalate. A 0.1 to 20 wt.% of graphene compared to the composite material may be used along with the polymer. The composites may have a Young modulus of 1200MPa or more. Also disclosed is a method of a melt-mixing process, a temperature of between 280-320ºC will be used at a speed of 50-100 rpm to produce a composite master-batch, prior to injection/compression moulding and extruding, and treatment with functional chemicals. Additionally disclosed is a method of preparing a yarn/fabric mixing graphene with polyethylene terephthalate (rPET) in a melt-spinning process with a 0.1 to 20 wt.% of graphene compared to the composite material at a temperature of between 280-300ºC to produce a polyester yarn. The composite may be used to manufacture a suitcase or be spun into yarn to provide a textiles product.

Description

PATENT APPLICATION

TWO-DIMENSIONAL MATERIALS BASED

RECYCLED POLYMER COMPOSITE

MATERIALS AND METHOD OF

PREPARATION

TENTS OF PATENT SPECIFICATION

Title of the Invention 3

Technical field of the Invention 3

Background of the Invention 3

Summary of the Invention 6

Brief Description of the Drawings 8

Detailed Description of the Drawings 9

Detailed Description of the Invention 11

Claims 16

Abstract of the Disclosure 20

SPE ATECAT

CROSS-REFEREN RELATED APPLICATIONS

No related applications are previously filed.

Title of the

Two-Dimensional Materials-Based Recycled Polymer Composite Materials and Method of Preparation Technical 1_001_1 The present invention disclosure relates to novel polymer composites. More particularly, the invention relates to a composition and a method of preparation for two-dimensional materials-based recycled polymer composite.

Background of the Invention

1_002i1 About 400 million tons of plastic are produced every year in the world with 40% of that is of single use and only 9% gets re-cycled worldwide. The plastic materials do not biodegrade and can hang around in the environment for hundreds of years. For example, a plastic bottle takes 450 years to biodegrade Each year, more than 8 million tons of plastics goes into the world oceans and 100,000 animals in the sea are killed by plastic. The amount (weight) of plastics will be more than the fish in the ocean by 2050. The European Parliament imposed a complete ban on a range of single-use plastics across the union in a bid to stop pollution of the oceans.

[3] Plastics is one of the most widely used and least expensive materials around the globe today. We use around 5 trillion plastic bags a year worldwide and only 1-3 percent of all plastics used are recycled. However, the biggest challenge for recycled plastic materials is the contamination with low grade materials; as a result, these provide poor quality and lower reusability than virgin materials.

[4] In previous studies some of the Patents such as EP20110702497, W02017066937A1 and CA2863296C describe graphene-based composites. However, the use of graphene and other two-dimensional materials to enhance mechanical and other properties of recycled polymers composites significantly have not been reported. Moreover, recycled materials suffer from poor performance properties due to the thermal ageing, mixing with other low-grade materials and recycling process. Also, the performance of recycle materials degrades with number of recycling stages (as a rule of thumb -recycling can be done maximum 3 times).

[5] These and many other problems have been long identified. Different solutions to the problems have been tried. However there exists no comprehensive solution to all the above problems. Therefore, the object of the invention overcomes above and other drawbacks from the prior art.

[6] To achieve above and other objects, the present invention provides a composite material which contains graphene or other two-dimensional materials and recycled polymers (e.g. Polycarbonate, Polyethylene Terephthalate, Polypropylene, Nylon, polyamide and other recycled polymers). The properties of a composite material containing two-dimensional materials are shown to be superior to those which contain only virgin or recycled polymers.

[007] Graphene and other two-dimensional materials have shown huge potential for nanocomposites (such as plastics) due to their excellent mechanical properties. Graphene provides high mechanical strength, excellent thermal and electrical properties and dimensional stability of the polymer matrix. Moreover, graphene materials have higher surface area. so make the weight of the final components much lighter.

Summary of the:Inventmeg

[8] The present invention provides two-dimensional materials-based recycled polymer composite and the related preparation method that overcomes the drawbacks mentioned above with reference to the prior art. in particular, the present invention relates to composite materials which contain two-dimensional materials (e.g. graphene) and recycled polymers (e. g. polycarbonate, polyethylene terephthalate). Advantageously, the properties of a composite material containing two-dimensional materials are shown to be superior to those which contain only virgin or recycled polymers.

[9] Even the methods of preparation herein described two-dimensional materials-based recycled polymer composites and uses thereof are subject of the present invention.

[01 0] In view of the above, the inventors of the present invention have prepared a novel two-dimensional materials-based recycled polymer composites capable of obtaining a sufficient physical property enhancing effect even when a small amount of two-dimensional material (e.g. graphene) is mixed to a recycled polymer substrate.

[01 I] In addition, the present invention provides a method for preparing a graphene/recycled polycarbonate composite.

[12] Furthermore, the present invention provides a method for preparing a graphene/recycled polyethylene terephthalate (rPET) master-batch.

[13] Furthermore, in the present invention, graphene and their derivatives such as graphene Nano Platelets (in short GNP, which contains more than 10 layers gaphene), graphene oxide (GO) and reduced graphene oxide (rG0), and other two-dimensional materials were used to enhance the properties of recycled polymer composites and their products.

[14] Accordingly, an object of the present invention using graphene and other two-dimensional materials significantly enhance mechanical and other properties of composites of recycled polymers.

[15] The present invention and its products have improved functionalities such as fire retardancy, anti-static, anti-UV, water repellency, anti-scratch etc. [16] Another important aspect for the present invention is the first innovative graphenebased smart suitcase which is made of 100% recycled plastics (e.g. polycarbonate). Such suitcase is durable and reusable, which will be lighter and stronger than existing products in the market.

[17] Other important aspect of the present invention is the melt-spinning of graphene/recycle polymers composites into textiles yarn with various performance properties that are useful in different applications of textile products such as sportswear, outerwear, workwear, active wear and shoes from recycled polyester (or nylon) yarns. Furthermore, yarns are woven or knitted into fabrics for various applications such as but not limited to fire retardancy, water repellence, anti-static, anti-UV and anti-bacterial.

:Brief Description of the Drawings

[18] Following drawings with reference numbers and exemplary embodiments are referenced for explanation purpose.

[19] FIG. 1 illustrates the flow chart of the general method of preparation of graphene/recycled polymer composites [20] FIG. 2 illustrates the basic processing mechanism in twin screw extruders/the basic structure of twin-screw extruder.

[21] FIG. 3 illustrates the basic structure of Injection/Compression moulding.

[22] FIG. 4 illustrates the product application (Graphene-based suitcase prototype).

[23] FIG. 5A illustrates the graph related to the young modulus of the graphene/rPC composites.

[24] FIG. 5B illustrates the graph related to the yield strength of the graphene/rPC composites.

Detailed Description of the Drawings

[0251 Now referring to the drawings, preferred embodiments of the invention are described below.

[026] FIG. 1 provides a brief workflow of different steps involved in preparation of graphene/recycled polymer composites. The first step involves mixing of graphene and other two-dimensional materials with recycled polymers, and then graphene/recycled polymer master-batch is produced. Further, twin screw extruder is used for processing the materials, especially in thermoplastic generation. In the next step, the material mix is processed through injection moulding machine to produce graphene/recycled polymer composites for further testing (e.g. mechanical, TGA, DSC etc).

[027[ FIG. 2 provides an illustration of twin-screw extruder where the materials are processed through the inlet (1) and twin screws (2) are used to efficiently mix the materials to further develop a master batch.

[28] FIG. 3 provides the diagrammatic illustration of the basic structure of Injection/Compression moulding. The illustration further provides different parts of the Injection/Compression moulding such as hopper (3), heater (4), hydraulic system (5), motor (6) and mould (7).

[29] FIG. 4 provides representation of a graphene-based suitcase prototype manufactured using the material developed in combination of graphene and recycled polymers. The Figure further provides representation of different advantages of the suitcase prototype such as Ejectable battery (8), TSA approved lock (9), Water proof capability (10) and 360-degree wheels (11) that provide better movement.

[30] FIG. 5A provides graph related to the young modulus of the graphene/rPC composites. Graphene powder was added to the recycle PC at various concentration (1-10 wt.-%). Here, the young modulus of the graphene/rPC composites increases almost linearly with the increase of graphene wt-% in the composites. The young modulus increases by -50% after adding 10 wt.-% graphene.

[31] FIG. 5B provides graph related to the yield strength of the graphene/rPC composites. Here, the yield strength increases with the increase of graphene wt-% in the composites formulation. Due to the incredible mechanical properties of graphene, it increases the strength and stiffness of the recycled composites. The young modulus increases by -50% after adding 10 wt.-% graphene.

Dthified Description of the

[32] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. The terms "GO, rGO, and GNP" is defined as Graphene Oxide, reduced Graphene Oxide and Graphene Nano Platelets (contain more than 10 graphene layers) respectively. Herein, the terms rPET, and rPC" is defined as recycled Polyethylene Terephthalate and recycled Polycarbonate, respectively. Furthermore, the terms TGA and DSC is defined as Thermal Gravimetric Analysis and Differential Scanning Calorimetry, respectively.

[33] The present disclosure provides a composition and method of preparation meant for novel two-dimensional material-based recycled polymer composites. In this novel composite, a small amount of two-dimensional materials are mixed to a recycled polymer substrate, thereby enhancing the properties of recycled polymers for various new applications.

[34.11n some embodiments, processing of the materials especially in thermoplastic generation using twin-screw extrusion. Further in some embodiments, after processing material by twin screw extruder, it usually gets a rough material. Further, injection/compression moulding has been used to prepare testing sample to test the properties (such as mechanical, TGA, DSC etc).

[35] In the present disclosure, both virgin and recycled polymers were used for the studies. In addition, graphene and their derivatives such as GNP, GO and rGO, and other two-dimensional materials were used to enhance the properties of recycled polymer composites and their products.

[36] The two-dimensional material may be graphene, graphene derivatives including GO, rGO or GNP or other two dimensional materials including MoS), hBN or WSefl.

[37] The recycled polymer substrate may be recycled polyethylene terephthalate, recycled polycarbonate, recycled polyamide (Nylon), recycled high density pol yethylene, recycled low density polyethylene, recycled polyvinyl chloride, recycled polypropylene, recycled polystyrene, recycled acrylic, recycled polylactic acid and fiber glass. Preferably the recycled polymer substrate is recycled polycarbonate or recycled polyethylene terephthalate.

[38] Preferably, the two-dimensional material makes up 0.1-20 wt.-% of the composite. More preferably the two-dimensional material makes up 0.1 -I 0 wt.-% of composite, for example I -10 wt.-%, for example 1-5 wt.-%. In one embodiment, for the preparation of graphene/polymer composites, graphene or other two dimensional materials are mixed with recycled polymers (and virgin polymer as well for comparison) at various wt.-% (0.1-20 wt.%) via melt mixing process using a twin-screw extruder in order to produce graphene/polymer composites.

[39] In one embodiment for recycled polycarbonate, 280-320 'C temperature is applied to melt-mix graphene and rPC at 50-100 rpm in order to produce graphene/rPC master-batch. Further, injection moulding machine is used to produce rPC/graphene composites for further testing (mechanical, TGA, DSC etc).

[40] In one embodiment recycled polyethylene terephthalate (rPET), 280 to 300°C temperature is applied to melt-mix graphene and rPET in order to produce graphene/rPET master-batch. Further, graphene/rPET is melt-spun into polyester yarn textiles. In the next step, various functional chemicals, for example deca bromo diphenyl ethane or antimony trioxide, ammonium polyphosphate or black phosphorus or polyurethane or fluorocarbon, are incorporated during mixing (or post-treatment after making yarn/fabric) to integrate functional properties such as fire retardancy, water repellence, anti-static, anti-UV, antibacterial etc. to textiles yarn.

[41] The components can be mixed together by a melt mixing process. In one embodiment, basic processing mechanism in twin-screw extruders is provided. Twin screw extruder is commonly used in processing of the materials, especially in thermoplastic generation. FIG. 2 describes the basic structure of twin-screw extruder with material inlet ( I) and two screws (2). Twin-screw extrusion equipment has a great flexibility wherefore the formulation being processed can be achieved because of this property. For instance, the direction of rotation and whether intermeshing can be converted to each other by adjusting two screws (2). Not only the direction of conveying elements but also kneading blocks and other designs can modify the construction of the screw so as to achieve specific mixing characteristics.

[42] After processing material by twin screw extruder, the obtained output product is a rough material. Further, injection/compression moulding is used to prepare testing sample to test the properties of the sample. Injection moulding is an important moulding method for thermoplastics. FIG. 3 provides a basic structure of Injection/Compression moulding.

[43] The injection moulding process consists of the following four stages. Initially, the polymer is injected into the mould cavity. The second stage is compaction pressurization phase, it applies a constant pressure to the material core to compensate for polymer shrinkage due to temperature and pressure effects. Thirdly, the component is cooled to a temperature where the component does not deform when pushed out of the mould at this temperature. At this stage, some new polymers (injection) are plasticized by the screw of the device for the next injection. Lastly, when the mould is opened or opened, the component is pushed out of the cavity [44] The present invention provides, world first graphene-based smart suitcase, which is made of 100% recycled plastics (polycarbonate). Such suitcase is an innovative, durable and reusable suitcase, which will be lighter and stronger than existing products in the market.

[45] By using sustainable materials such as recycled plastics, the present invention contributes to the environmental protection by the reduction of CO, emission and waste prevention. The graphene-enhanced recycled polycarbonate systems impart smooth-touch, scratch-resistant and better impact properties. Thus, help to keep personal items protected and securely inside the luggage without adding additional weight. In the FIG. 4, Graphenebased suitcase prototype, a true smart luggage, is integrated with ejectable battery, TSA lock, GPS locator and 360° wheels for smooth ride on any surface.

[46] Other leading applications of the present invention is textile products such as, but not limited to sportswear, outerwear, workwear, active wear and shoes from recycled Polyester or nylon yarns. Such yarns are woven or knitted into fabrics with various performance properties such as, but not limited to, fire retardancy, water repellence, anti-static, anti-UV, anti-bacterial for various applications.

[47] FIG. 5A provides graphical visualization of the young modulus of the graphene/rPC composites. According to this graph, the graphene powder was added to the recycle PC at various concentration (1-10 wt.-%). FIG. 5A shows the young modulus of the graphene/rPC composites increases almost linearly with the increase of graphene wt.-% in the composites. The young modulus increases by -50% after adding 10 wt.-% graphene. Preferably the composite of the present invention has a young modulus of 1200 MPa or over, more preferably 1350 MPa or over, even more preferably 1500 MPa or over.

[48] Similarly, FIG. 5B shows the increase of yield strength with the increase of graphene wt.-% in the composite's formulation. Due to the incredible mechanical properties of graphene, it increases the strength and stiffness of the recycled composites.

[49] By adding the graphene in to polymer mixture, the final of this composite have some of the unique advantages like 60% stronger composites, lighter composites, increases the use (recycling) of same materials/product multiple times without compromising the properties, enhanced functional properties (e.g. fire retardancy, water repellency, anti-UV, anti-static, thermal and electrical) of the products, environmentally friendly (less waste and less carbon emission etc), multi-functional and smart products.

Claims

Oalots 1. A two-dimensional materials-based recycled polymer composites comprising: a recycled polymer substrate: one or more two-dimensional material 2. The two-dimensional materials-based recycled polymer composite of claim 1, wherein recycled polymer is selected from a list of recycled polyethylene terephthalate, recycled polycarbonate, recycled polyami de (Nylon), recycled high density polyethylene, recycled low density polyethylene, recycled polyvinyl chloride, recycled polypropylene, recycled polystyrene, recycled acrylic, recycled polylactic acid or fiber glass.3. The two-dimensional materials-based recycled polymer composite of claim 1 or 2, wherein the two-d mens onal material is selected from graphene, graphene oxide (GO), reduced graphene oxide (rG0), Graphene Nano Platelets (GNP), MoS2, hBN or WSe2.4. The two-dimensional materials-based recycled polymer composite of claims 1 to 3, wherein the composites includes post treatment with functional chemicals.5. The two-dimensional materials-based recycled polymer composite of claims 1 to 4, wherein the composites has a Young modulus of 1200 MPa or more.6. The two-dimensional materials-based recycled polymer composite according to any of claims 1 to 5, wherein the two-dimensional material comprises 0.1-20 wt.-% of the composite.7. The use of a composite according to any of the claims I to 6 for a suitcase.8. The use according to claim 7 wherein the two-dimensional material is graphene or graphene derivatives (e. g. GNP, GO or K10).9. The use according to claim 7 or 8 where in the recycled polymer substrate is polycarbonate.10. The use of a composite according to any of claims 1 to 6 wherein the composite is melt-spun into fibres/yarn to provide a textiles product.11. The use according to claim 10 wherein the two dimensional materials is graphene or graphene derivatives (e. g GNP, GO or rGO) and the recycled polymer substrate is recycled polyethylene terephthalate.12. A method for preparing two dimensional materials-based recycled polycarbonate composite comprising the steps of: a. Melt-mixing of graphene or other two dimensional materials to recycled polycarbonate, wherein the graphene and other two dimensional materials are 0.1 to 20 wt.% of the composite material; h. using melt-mixing process in order to produce graphene/recycled polycarbonate master-batch; c. having melt-mixing temperature in the range of 280-320 °C and processing speed at 50-100 rpm in order to produce graphene/recycled polycarbonate master-batch; d. processing of the produced material using injection/compression moulding to produce rPC/graphene composites for further testing.13. A method for preparing a two dimensional materials-based recycled polyethylene terephthalate (rPET) composite comprising the steps of: a. Melt-mixing of graphene or other two dimensional to recycled polyethylene terephthalate (rPET), wherein the graphene and other two dimensional materials are 0.1 to 20 wt.% of the composite material; b. using the melt-mixing process in order to produce graphene/recycled polyethylene terephthalate (rPET) master-batch; c. having melt-mixing temperature in the range of 280 to 300 °C in order to produce graphene/recycled polyethylene terephthalate (rPET) master-batch; d. melt-spinning of graphene/ recycled polyethylene terephthalate (rPET) master-batch into polyester yarn textiles; e. incorporating polymers during mixing (or post-treatment after making yarn/fabric) to bring functional properties to textile yarn.14. The method according to claim 12 or 13 wherein the two-dimensional material is graphene or graphene derivatives (e.g. GNP, GO or rG0).