MX2012008962A - Process for obtaining biopolymers from a solid isolated from avocado pits and obtained biopolymers. - Google Patents

Abstract

The plastics and polymers resulting from petroleum cause severe damages to ecosystems, therefore novel and environmentally friendly alternatives have been generated for replacing conventional plastics. The polymers resulting from natural sources used for replacing petroleum based polymers are best known as biopolymers. The biopolymers currently available on the market, besides being efficient and useful in a wide range of applications, present a serious problem since these are made mainly of food sources such as maize or potato. Manufacturing sustainable and environmentally friendly products with potential food sources results in a contradiction; so that the present invention provides a process for obtaining biopolymers from a solid isolate from avocado pits. Avocado pit is an important agroindustrial waste which solves this problem in an integral manner. The process consists in the homogenization of the solid isolate of avocado pit with natural or synthetic waxes, natural plasticizer s, optional natural compounds for regulating the degradation period and additives such as pigments. The homogenized product is extruded along with other polymers and granulated for obtaining a biopolymer that may be used for manufacturing biodegradable products by the conventional methods of the plastic models.

Description

Process to obtain biopolymers from a solid isolate derived from the avocado seed and the biopolymers obtained DESCRIPTION OBJECT OF THE INVENTION The present patent application is intended to provide a process for obtaining biopolymers from a solid isolate derived from the avocado seed and the biopolymers obtained. These biopolymers are prepared by mixing natural components that include: a solid isolate derived from avocado seed, natural or synthetic waxes and plasticizer of natural origin; and a compound optionally of natural origin that helps to regulate the degradation of the biopolymer. With the biopolymer obtained, biodegradable products can be manufactured by injection or blow molding.

BACKGROUND There is a huge need to develop materials that replace conventional plastic, as new consumers demand more and more products that do not harm the environment. Several companies have developed biodegradable polymers from plant sources, which have been called biopolymers. However, more than 60% of current biopolymers are produced from potential sources of food, such as corn and potatoes, and this makes them unsustainable. The current industries and markets are aware of this problem and various technologies are being developed around this.

Biopolymers arise when looking for a sustainable alternative to the need to change oil as the main source for the manufacture of plastics. However, the current biopolymers, although they have proven to be very efficient and friendly to the environment, have a very important problem, the vast majority is made from raw materials that are potential sources of food for humans. Currently, the biopolymer market mainly uses starch as a raw material, as this turns out to be the simplest and perhaps the least expensive process for the production of this material. Within this heading, the starch that is used for the manufacture of biopolymers comes from sources such as potatoes, corn or wheat. All these materials, which together account for approximately 60% of the biopolymers market, turn out to be potential sources of food (Chair Ecoembes Medio Ambiente at Universidad Politécnica de Madrid, 2007).

This problem with current biopolymers opens an enormous opportunity to the development of new biodegradable materials to replace the biopolymer from food sources, as industries begin to choose to stop using this type of biopolymers. The present invention offers a solution to the problem described above by providing biopolymers from a solid isolate derived from the avocado seed. These biopolymers are capable of being used for the manufacture of biodegradable products manufactured with the methods of injection, extrusion or blowing. It should be noted that the avocado seed is currently a waste product with no value in the market, and that in the present patent application is used to solve the latent problem of finding alternative sources that do not compete with food sources to provide biopolymers.

The current panorama of biodegradable plastics according to "The Royal Veterinary and Agricultural University" classifies biopolymers into 3 main groups according to their origin and production.

/. Polymers extracted from natural sources.

Which are products extracted from natural resources among which cellulose, starch, chitosan and to a lesser extent proteins such as casein, soy and collagen stand out for their use. The most common is that these types of polymers are obtained from potential sources of food. 2. Polymers produced by classical chemical synthesis using renewable monomers.

Although a wide range of derivatives can be found in this sector, polylactic acid (PLA) clearly dominates this type of biopolymers. PLA can be derived from the fermentation of carbohydrates from products such as corn, wheat, beet, potato or waste from basically any natural resource. This type of polymers is derived again from raw materials that are potential sources of food. 3. Polymers produced by micro-organisms or genetically modified bacteria.

This classification includes polyhydroxyalkanoates (PHAs), among which the polyhydroxybutyrate (PHB) stands out for its consumption, which, being produced by bacteria, has several advantages, as they conserve carbon, and they are highly versatile in the industry due to their biodegradable characteristics. Its disadvantage lies in the high cost of producing these materials.

Currently, the growing market dedicated to the development and production of biodegradable materials in the world is known. There are also efforts to develop technologies aimed at additives and compositions that, mixed with traditional plastics, help biodegrade them. An example of these technologies are the so-called oxo-biodegradable additives. The disadvantage of these products is that when degraded they release materials that can become toxic or harmful to the environment. Much of this research is financed by companies such as BASF, DuPont, Mitsubishi Gas Química, Novamont, among others, concentrating their generation of patents on raw materials and applications for biodegradable packaging.

In conclusion, it can be observed that the main attribute of the biopolymer is the raw material used to produce it, seeking that the process of making these materials is sustainable. Based on the foregoing, a new sustainable alternative in biodegradable plastics materials from a solid isolate derived from the avocado seed is provided in the present patent application.

BRIEF DESCRIPTION OF THE FIGURES Figure 1. Schematic block diagram of the process to obtain biopolymers from a solid isolate derived from the avocado seed motive of this patent application.

DETAILED DESCRIPTION OF THE INVENTION The invention consists in a process for obtaining biopolymers from a solid isolate derived from the avocado seed, comprising the following stages as shown in Figure 1: a) Homogenize (1) a solid isolate derived from the avocado seed with at least one of the following waxes: natural waxes such as beeswax or candelilla wax, synthetic waxes such as oxidized polyethylene wax or paraffin wax. The relationship between waxes and the solid isolate derived from the avocado seed ranges from 1: 1 to 1: 20 weight / weight. When two waxes are combined, the ratio between them is optionally 1: 1 to 1: 30 weight / weight. b) Add (2) natural plasticizer to the homogenate obtained in a). The ratio between the total weight of the plasticizer and the biopolymer obtained at the end ranges from 1:10 to 3:10 weight / weight. c) Add (3) antibacterial compound of natural origin that retards the degradation of the biopolymer obtained at the end. The ratio between the compound of natural origin and the biopolymer obtained at the end ranges from 1: 1000 to 50: 1000 weight / weight. d) Extruding (5) the product obtained in c) with at least one of the following polymers: polyethylene, polystyrene, polyvinyl chloride, polypropylene or polylactic acid. e) Granular (6) the extruded obtained in d) Optionally between steps c) and d) add (4) at least one of the following additives: pigments, bleaches, stabilizers, foaming agents, flame retardants, plasticizers, UV light absorbers or antistatics.

Optionally after step e), the granulate and mold (7) to obtain biodegradable products by injection or blow.

Optionally stages b) and c) are carried out simultaneously.

The characterization of the solid isolate derived from the avocado seed is shown in tables 1, 2, 3 and 4.

Table 1. Organoleptic and Physical Characteristics Table 2. Solubility at 25 ° C Table 3. Solubility at 45 ° C Table 4. Bromatological Analysis Example 1. Preferred embodiment.

Obtaining partially biodegradable biopolymers a) Homogenize at room temperature 72 kg of a solid isolate derived from the avocado seed with 10 kg of crushed bee wax and 10 kg of crushed oxidized polyethylene wax. b) Add 5 kg of Soya Lecithin to the homogenate obtained in a). c) Add 2 kg of grapefruit seed extract to the homogenate obtained in a). d) Add 1 kg of vegetable pigment to the homogenized obtained in the previous steps and mix mechanically for 1 hour. e) Extrude the product obtained from the previous steps to an exit temperature of the extruder of 200 ° C with 50 kg of high density polyethylene. f) Granulate the extrudate obtained in e) by means of a pelletizer to obtain pellets with an average length of 1 cm. g) Mold by injection at 200 ° C to obtain biodegradable products from the biopolymer obtained in the previous steps.

Example 2. Preferred embodiment Obtaining 100% biodegradable biopolymers a) Homogenize at room temperature 72 kg of a solid isolate derived from the avocado seed with 10 kg of crushed bee wax and 10 kg of candelilla wax. b) Add 5 kg of Soya Lecithin to the homogenate obtained in a). c) Add 2 kg of grapefruit seed extract to the homogenate obtained in a). d) Add 1 kg of vegetable pigment to the homogenate obtained in the previous steps and mix mechanically for 1 hour. e) Extrude the product obtained from the previous steps to an exit temperature of the extruder of 200 ° C with 50 kg of polylactic acid. f) Granulate the extrudate obtained in e) by means of a pelletizer to obtain pellets with an average length of 1 cm. g) Mold by injection at 200 ° C to obtain biodegradable products from the biopolymer obtained in the previous steps.

Claims (20)

CLAIMS Having described my invention enough, I consider it as a novelty and therefore claim as my exclusive property, what is contained in the following clauses:

1. A process for obtaining biopolymers from a solid isolate derived from the avocado seed, characterized in that it comprises the following stages; a) Homogenize a solid isolate derived from the avocado seed with at least one of the following waxes: natural waxes and synthetic waxes; b) Add natural plasticizer to the homogenate obtained in a); c) Add natural compound that delays the degradation of the biopolymer obtained at the end; d) Extrude the product obtained in c) with at least one polymer; e) Granulate the extrudate obtained in d)

2. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that in step a) the natural waxes are: beeswax or candelilla wax.

3. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that in stage a) the synthetic waxes are: oxidized polyethylene wax or paraffin.

The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1, characterized in that in step a) the relation between waxes and the solid isolate derived from the avocado seed ranges from 1: 1 to 1: 20 weight / weight.

The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that in step a) when two waxes are combined, the ratio between them optionally is 1: 1 to 1: 30 weight /weight.

The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1, characterized in that in step b) the ratio between the total weight of the plasticizer and the biopolymer obtained at the end ranges from 1: 10 to 3: 10 weight / weight.

The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 6 characterized in that in stage b) the plasticizer of natural origin is lecithin.

The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that in step c) the ratio between the compound of natural origin and the biopolymer obtained at the end ranges from 1: 1000 to 50: 1000 weight / weight.

The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 8 characterized in that in step c) the compound of natural origin is grapefruit seed extract.

10. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that optionally stages b) and c) are carried out simultaneously.

11. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that between step c) and step d) optionally at least one additive is added.

12. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that the additive is at least one of the following: pigments, bleaches, stabilizers, foaming agents, flame retardants, plasticizers , UV light absorbers or antistatic.

13. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that in step d) the polymer is at least one of the following: polyethylene, polystyrene, polyvinyl chloride, polypropylene or polylactic acid.

14. The process for obtaining biopolymers from a solid isolate derived from the avocado seed according to claim 1 characterized in that after step d) the granulate obtained optionally is molded to obtain biodegradable products by injection or blow.

15. A biopolymer characterized in that it is obtained from the process contained in claims 1 to 14.

16. The solid isolate derived from the avocado seed used in the process claimed in clauses 1 to 14, characterized in that its composition comprises 0.1 to 2% fiber, 80 to 95% carbohydrates, 0.1 to 2% lipids, 0.3 to 4 % protein, 8 to 14% humidity and 0.1 to 0.8% ash.

17. The solid isolate derived from the avocado seed according to claim 16, characterized in that its particle size ranges from 0.04 to 3 millimeters.

18. The solid isolate derived from the avocado seed according to claim 16, characterized in that its pH ranges from 6.0 to 7.0.

19. The solid isolate derived from the avocado seed according to claim 16 characterized in that its density ranges from 400 to 600 kg / cm3

20. The solid isolate derived from the avocado seed according to claim 16, characterized in that it is soluble in water.