A biodegradable flexible polyurethane foam formulation and production method thereof

Abstract

The invention is related to a biodegradable flexible polyurethane foam comprising at least one bio-based polyol in predetermined percentages and at least one natural origin polymer in predetermined percentages and at least one biodegradable polyol in predetermined percentages for preventing negative effects such as crumbling, split formation and loss of hardness.

Description

[0001] A BIODEGRADABLE FLEXIBLE POLYURETHANE FOAM FORMULATION AND PRODUCTION METHOD THEREOF

[0002] Technical Field

[0003] The invention is related to a biodegradable flexible polyurethane foam formulation in which natural origin polymer (NOP), bio-based polyol (BBP) and biodegradable polyol (BDP) are used together and, a production method thereof.

[0004] Prior Art

[0005] In the world, approximately 25 million tons of polyurethane foam is produced in a year. Production of flexible polyurethane foam constitutes approximately 67% of this production. Traditional flexible polyurethane foams consist of fossil based raw materials. At the prior art, flexible polyurethane foams are formed as a result of the reaction of polyol and diisocyanate and, these raw materials are petrochemical based and do not degrade biologically. Therefore, approximately 5 million tons of plastic waste is produced in a year. Said waste is formed due to the fact that the flexible polyurethane foam completes its lifetime and the waste formed becomes a product that is harmful to the environment. For this product not to harm to the environment, it needs to be a biologically degradable product.

[0006] At the state of the art, in the study of “The biodegradable cellulose-derived polyol and polyurethane foam, Marzena Szpilyk et al.y it is mentioned that cellulose based polyester polyol was synthesized and the synthesized polyol was used in rigid polyurethane foam. In said document, it is stated that experiments of biological degradation were made to the obtained rigid polyurethane foams by using soil ecosystem for 28 days. In the analysis made, it was observed that the rigid polyurethane foam biologically degraded approximately 70%. In the invention described in said document, it has been never mentioned that flexible polyurethane foam is produced by using natural origin polymers, bio-based polyol and biodegradable polyol and they form a synergistic effect by coming together. In addition, the study performed is about rigid polyurethane foam.

[0007] At another state of the art, in the study of “An intumescent flame-retardant system based on carboxymethyl cellulose for flexible polyurethane foams with outstanding flame retardancy, antibacterial properties, and mechanical properties, Ping Li elal.", carboxymethyl cellulose was used alone and in solid form inside the flexible polyurethane foam, it is mentioned that flame retardant, antibacterial and mechanical properties of obtained flexible polyurethane foam were examined. In the invention described in said document, it has been also never mentioned that flexible polyurethane foam is produced by using natural origin polymers, bio-based polyol and biodegradable polyol and they form a synergistic effect by coming together.

[0008] At another state of the art, in the patent document with the number of JPH06157799A, monosaccharide is used as powder in a urethane system, and it is stated that biological degradation speed of the obtained product is measured. However, when details of said document are analyzed, the form of foam is affected negatively as powder amount used during production of polyurethane foam increases technically, and mechanical properties of the foam decrease. In addition to this negative effect, it has been never mentioned in the document that bio-based polyol and biodegradable polyol are used besides natural origin polymers (cellulose, starch, protein etc.) used as powder and they form a synergistic effect by coming together.

[0009] At another state of the art, in the patent document with the number of CN102675581B, it is mentioned that liquified lignin is used in the polyurethane foam and biologically degradable polyurethane foam is obtained. In the invention described in said document, it has been never mentioned that production of flexible polyurethane foam happens by using natural origin polymers, bio-based polyol and biodegradable polyol in predetermined percentages and they form a synergistic effect by coming together.

[0010] In the patent with the number of W02007 / 095713A1 at another state of the art, it is mentioned that for the polyurethane foam to be biodegradable when synthesized, polyhydroxybutyrate in a predetermined percentage is added into it and it is kept in a mold at a certain temperature. However, it is known technically that because polyhydroxybutyrate does not have OH groups in its structure, it behaves like an additive during polyurethane reaction, and this creates a negative effect on the mechanical properties of the foam. In said document, the polyurethane foam reaction is performed in the mold and heat energy is benefitted for the reaction. There is not an invention wherein natural origin polymers, biobased polyol and biodegradable polyol are used together to be able to provide biodegradability for flexible biodegradable polyurethane foam produced in a tunnel without heating process and they form a synergistic effect by coming together at the state of the art. In the patent with the number of WO2021148064 at another state of the art, it is mentioned that saccharide and aliphatic isocyanate are introduced to a preliminary reaction. Then, it is stated that polyurethane foam is obtained in a mold by using the obtained material and 20% to 70% biodegradable polyester polyol and by heating. There is not an invention wherein natural origin polymers, bio-based polyol and biodegradable polyol are used together to be able to provide biodegradability for flexible biodegradable polyurethane foam produced in a tunnel without heating process and they form a synergistic effect by coming together at the state of the art. Besides, it is known that degradation percentage of aliphatic isocyanate is quite low. Therefore, a material having a higher degradation percentage should be preferred.

[0011] In the patent document with the number of JP11236429A2 at another state of the art, it is mentioned that biodegradable polyurethane composite is obtained by using molasses fiber or powder as mold material. With reference to technical information, powder or fibers mentioned in the invention which are not processed have limited applications in material formation, they create negative effects like crumbling in the material. Therefore, obtaining biodegradable flexible polyurethane foam should be aimed by using different substances not mentioned in the document.

[0012] At the state of the art, 100 parts of polyol by weight is used in total in the formulation of flexible polyurethane foam and other raw materials in the formulation are proportioned according to it. If biodegradable foam production happens by using only bio-based polyol in the formulation, the amount of bio-based polyol in the 100 parts of polyol in the formulation may be 1 to 39 parts. In this application mentioned, when bio-based polyol in the formulation comprising 100 parts of polyol by weight in total is used as 40 parts and more by weight, splitsform in the polyurethane foam and at the same time, it is observed that hardness of the polyurethane foam decreases. If biodegradable foam production is realized by using only biodegradable polyol in the formulation, the amount of biodegradable polyol in 100 parts of polyol in the formulation may be 1 to 5 parts. In this application, when the biodegradable polyol is used more than 5 parts, shrinkage, closed cell forming in the polyurethane foam and hardens of the polyurethane foam are observed. If biodegradable foam production is realized by using only natural origin polymer in the formulation, the amount of the natural origin polymer added to the formulation in addition to 100 parts of polyol in the formulation may be 1 to 5 parts. In this application, when natural origin polymer is used more than 5 parts, crumbling occurs in the polyurethane foam. In short, when looked at the state of the art, although there are flexible polyurethane foams in which only natural origin polymer and bio-based polyol and biodegradable polyol are used one by one, there are not biodegradable flexible polyurethane foams in which three of them are used together. Therefore, there is not an invention at the state of the art wherein natural origin polymers, bio-based polyol and biodegradable polyol are used together in percentages such that it increases biodegradability of the flexible polyurethane foam and they form a synergistic effect by coming together in order to be able to increase biodegradability for flexible biodegradable polyurethane foam.

[0013] Summary of the Invention

[0014] The aim of the invention is to realize a biodegradable flexible polyurethane foam formulation and production method in which natural origin polymer, bio-based polyol and biodegradable polyol are used together.

[0015] In the invention, production of biodegradable flexible polyurethane foam has been realized by using at least one natural origin polymer, bio-based polyol and biodegradable polyol together in certain percentages. Said three substances have been used in percentages which will increase biodegradability of the final flexible polyurethane foam.

[0016] In the invention, biodegradable flexible polyurethane foam has been obtained in which a synergistic effect has been created by using natural origin polymers (cellulose, starch, protein etc.), bio-based polyol and biodegradable polyol together and consequently, the biodegradability rate has been increased. Furthermore, negative effects such as crumbling, split formation, loss of hardness in the material have been removed by the synergistic effect mentioned.

[0017] Description of the Figures

[0018] Figure 1. It is the reaction scheme of flexible polyurethane foam at the state of the art.

[0019] Detailed Description of the Invention

[0020] For preventing negative effects such as crumbling, split formation and loss of hardness, biodegradable flexible polyurethane foam formulation of the invention comprises at least one natural origin polymer in predetermined percentages and at least one bio-based polyol in predetermined percentages and at least one biodegradable polyol in predetermined percentages. Production of flexible polyurethane foam has never been studied before in which all three of biodegradable materials in the formulation are together with all other chemicals at the same time. Natural origin polymers mentioned are cellulose and / or starch and / or protein etc. but should not be intended to be limited to them. In the invention, natural origin polymer is in the form of powder and / or fiber. Natural origin polymer mentioned is preferably in the form of powder. Also, bio-based polyol mentioned is the polyol obtained from, but not limited to natural oils such as palm oil, soy oil, sunflower seed oil. In addition, biodegradable polyol is polyols obtained from materials such as starch and / or chitin and / or chitosan and / or cellulose and / or lignin etc. and / or the polyol synthesized by using polysaccharide but should not be intended to be limited to them.

[0021] In the formulation of the invention, bio-based polyol, natural origin polymer preferably in the form of powder and biodegradable polyol have been used together.

[0022] If biodegradable foam production is realized bu using all three of bio-based polyol and biodegradable polyol and natural origin polymer together in the formulation, the formulation of biodegradable flexible polyurethane foam comprises 40 to 50 parts of bio-based polyol, 8 to 12 parts of natural origin polymer and 8 to 12 parts of biodegradable polyol by weight. To obtain biodegradable flexible polyurethane foam which has the most effective and desirable property, the formulation comprises 40 parts of bio-based polyol, 10 parts of natural origin polymer, 10 parts of biodegradable polyol.

[0023] If and only if all three of them are used in these percentages, it is observed that they cover negative properties of each other (compansate each other) and create a synergistic effect and therefore, remove negative effects such as crumbling. In other words, because they can be used more when used together compared to their usage one by one in the formulation, this has affected biodegradability in positive way. Bio-based polyols comprise a lot of secondary OH groups due to their nature, they have lower reactivity than a standard polyol. That’ s why, when they are used in flexible polyurethane foam, they cause negative situations such as decreasing of mechanical properties and formation of lots of open pores and further, split formation inside flexible polyurethane foam because of slowing the reaction down and weak bondings. Biodegradable polyols cause shrinkages by increasing number of closed cells and hardens of the system (polyurethane foam system) when they are used more than a certain percentage due to the fact that they behave like crosslinker when they are used during the production of flexible polyurethane foam because they have high OH value. Although natural origin polymers comprise OH bonds in their structures, they behave like filler when they are used more than a certain percentage because of being in the form of powder or fiber. And they reduce mechanical properties of the system. At the same time, they cause crumbling by weakening the bonds formed during reaction. By using three materials at the same time, the materials weakening the structure of flexible polyurethane foam mentioned above and the materials increasing cross-linking are used together and therefore, they neutralize negative properties of each other.

[0024] The OH value of bio-based polyol used in the formulation is 50-80 mg KOH / g and its molecular weight is 2500 g / mol. The OH value of biodegradable polyol is 500-700 mg KOH / g. The OH value of natural origin polymer is 100-150 mg KOH / g.

[0025] In the invention, the polyurethane foam reaction is performed in a tunnel, not in a mold and therefore, no heat is required for the reaction. In said reaction, biodegradable flexible polyurethane foam has been obtained by mixing polyol and other raw materials and aromatic isocyanate (toluene diisocyanate-TDI) having higher biodegradability compared to aliphatic isocyanates via a high-speed mixer. Namely, the percentage of biodegradability in the flexible polyurethane foam has been increased by preferring aromatic isocyanate in the system. Furthermore, biodegradable flexible polyurethane foam has been obtained by coming together of said materials in the invention.

[0026] With this invention, the conventional flexible polyurethane foam which is not biologically degradable has become biodegradable.

[0027] For preventing negative effects such as crumbling, split formation and loss of hardness, obtaining method of biodegradable flexible polyurethane foam is synthesized according to the steps below:

[0028] In the first stage, mixing all three of at least one bio-based polyol, at least one biodegradable polyol and at least one natural origin polymer in predetermined percentages at the same time together with all of other chemicals via a mixer having a predetermined speed and putting it to the tunnel,

[0029] In the second stage, proceeding of the material in the tunnel via a conveyor by rising during the flexible polyurethane foam reaction, In the third stage, completing the flexible polyurethane foam reaction.

[0030] After the flexible polyurethane foam reaction is completed, the product is cut and put into the shelves.

[0031] The speed of the mixer mentioned in the first stage is preferably 4000 - 6000, more preferably 5000 rpm.

[0032] The bio-based polyol used in the first stage of the method is the polyol obtained from, but not limited to natural oils such as palm oil, soy oil, sunflower seed oil. In addition, similarly, the biodegradable polyol used in the first stage of the method is polyols obtained from materials such as starch and / or chitin and / or chitosan and / or cellulose and / or lignin etc. and / or the polyol synthesized by using polysaccharide but should not be intended to be limited to them. The natural origin polymers used in the first stage of the method are in the form of powder and / or fiber, but not limited to them. Natural origin polymer may be, but not limited to cellulose and / or starch and / or protein etc. Also, said cellulose may be, but not limited to microcrystalline cellulose and / or cellulose fiber and / or bamboo fiber etc.

[0033] For all flexible polyurethane foams indicated in each stage above, quality control analysis such as density, hardness compression set resilience tensile strength and elongation at break have been performed and compared with standard flexible polyurethane foam in the Table- 1

[0034] Table-1: Comparison of physical parameters of standard foam or foam comprising each substance alone and biodegradable flexible polyurethane foam of the invention

[0035] As seen from Table-1, when biodegradable flexible polyurethane foam of the invention in which there are all three substances is compared with the foam comprising each of them one by one and with the standard foam, similar physical properties with the standard foam are obtained. Therefore, an equivalent product (alternative to the standard product) whose physical properties do not change much is obtained with the formulation and method of the invention.

[0036] After at least one flexible polyurethane foam obtained with the method and cut in predetermined sizes and at least one standard flexible polyurethane foam were weighed, they were buried in soil for the biodegradability test. Buried flexible polyurethane foams were taken out at certain weeks, cleaned via a brush, washed and waited in a drying oven for drying until getting to a constant weight. Flexible polyurethane foams getting to a constant weight were weighed and biodegradability percentages were determined with the calculation of weight loss.

[0037] Table-2: Comparison of biodegradability percentages of foam comprising each substance alone and biodegradable flexible polyurethane foam of the invention having all three substances

[0038] From the Table-2, when biodegradable flexible polyurethane foam of the invention having all three substances is compared with the foam comprising each of them one by one and with the standard foam, a flexible polyurethane foam having increased biodegradability percentage has been obtained.

[0039] In short, the invention is related to obtaining biodegradable flexible polyurethane foam comprising all three substances of bio-based polyol, natural origin polymer and biodegradable polyol. With the invention, the conventional flexible polyurethane foam which is not biologically degradable has become biodegradable.

[0040] As a result, with the formulation and method of the invention, biodegradable flexible polyurethane foam has been obtained. Therefore, a more beneficial product to the environment has been obtained with biologically degradable flexible polyurethane foam. For decreasing the harm to the environment to the minimum and contributing to preventing the global warming, the invention has been realized.

[0041] Industrial Applicability of the Invention

[0042] The invention is related to the production method of biodegradable flexible polyurethane foam comprising all three of bio-based polyol, natural origin polymer and biodegradable polyol and to the biodegradable flexible polyurethane foam produced with said method, and it is industrially applicable.

[0043] The invention is not limited to the descriptions above, a skilled person in the art can perform different embodiments of the invention easily. These should be interpreted within the protection scope of the invention claimed with the claims.

Claims

CLAIMS1. For preventing negative effects such as crumbling, split formation and loss of hardness; a biodegradable flexible polyurethane foam formulation comprising at least one biobased polyol in predetermined percentages or at least one natural origin polymer in predetermined percentages or at least one biodegradable polyol in predetermined percentages such that each of them is alone; characterized by comprising at least one bio-based polyol in predetermined percentages and at least one natural origin polymer in predetermined percentages and at least one biodegradable polyol in predetermined percentages wherein all three of them are together with all other chemicals at the same time.

2. Foam formulation according to claim 1, characterized by comprising 40 to 50 parts of bio-based polyol, 8 to 12 parts of natural origin polymer and 8 to 12 parts of biodegradable polyol by weight.

3. Foam formulation according to claim 2, characterized by comprising 40 parts of biobased polyol, 10 parts of natural origin polymer and 10 parts of biodegradable polyol by weight.

4. Foam formulation according to claim 3, characterized by comprising natural origin polymer which is cellulose and / or starch and / or protein etc.

5. Foam formulation according to claim 4, characterized by cellulose which is microcrystalline cellulose and / or cellulose fiber and / or bamboo fiber etc.

6. Foam formulation according to claim 5, characterized by comprising natural origin polymer in the form of powder and / or fiber.

7. Foam formulation according to claim 6, characterized by comprising bio-based polyol obtained from natural oils such as palm oil, soy oil, sunflower seed oil.

8. Foam formulation according to claim 7, characterized by comprising biodegradable polyol obtained from materials such as starch and / or chitin and / or chitosan and / or cellulose and / or lignin etc. and / or synthesized by using polysaccharide.

9. Foam formulation according to claim 8, characterized by bio-based polyol having 50- 80 mg KOH / g and biodegradable polyol having 500-700 mg KOH / g and natural origin polymer having 100-150 mg KOH / g as OH values.

10. Foam formulation according to claim 9, characterized by comprising aromatic isocyanate added right after polyol and other raw materials are mixed.

11. For preventing negative effects such as crumbling, split formation and loss of hardness; a biodegradable flexible polyurethane foam obtaining method produced according to the steps below characterized by comprising the steps below andIn the first stage, mixing all three of at least one bio-based polyol, at least one biodegradable polyol and at least one natural origin polymer in predetermined percentages at the same time together with all of other chemicals via a mixer having a predetermined speed and putting it to the tunnel,In the second stage, proceeding of the material via a conveyor by rising in the tunnel during the flexible polyurethane foam reaction,In the third stage, completing the flexible polyurethane foam reaction.

12. A method according to claim 11, characterized by bio-based polyol which is polyol obtained from natural oils such as palm oil, soy oil, sunflower seed oil; biodegradable polyol which is polyols obtained from materials such as starch and / or chitin and / or chitosan and / or cellulose and / or lignin etc. and / or polyol synthesized by using polysaccharide; natural origin polymer which is cellulose and / or starch and / or protein etc., which are used in the first stage of the method.

13. A method according to claim 12, characterized by natural origin polymer used in the first stage of the method which is in the form of powder and / or fiber.

14. A method according to claim 13, characterized by the mixer speed mentioned in the first stage of the method which is preferably 4000-6000 rpm, more preferably 5000 rpm.

15. A method according to any of claims 11 to 14, characterized by performing reaction in the tunnel.

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