TWI398477B - Biodegradable Composites and Their Making Methods - Google Patents

Description

Biodegradable composite material and preparation method thereof

The present invention relates to a biodegradable composite material and a process for the preparation thereof, and more particularly to a composite material using maleic anhydride or an acrylic graft copolymer to increase compatibility.

At present, with the continuous expansion of plastic use and the increasing consumption, plastic waste is also increasing. This is a heavy burden for the environment and ecology. Therefore, in order to solve the environmental impact caused by plastic waste, decomposable plastic enamel has emerged. Its demand characteristics are required before and during use. Similar performance, and after completing its function, it can be quickly decomposed into environmentally friendly substances under natural environmental conditions. However, such plastics often have poor mechanical properties or thermal properties and are difficult to process, so they must be modified.

In addition, various fillers are often added to the composite material to achieve various uses, which may be organic or inorganic, and the form may be powdery or long fibers. Their purpose can be used as an extender, and sometimes an reinforced effect is achieved to make the composite stronger. The most commonly used fillers are organic materials such as wood flours or starch, or minerals and minerals such as asbestos and mica. The type of filler used is an important factor in the nature of the final product, so its choice is the most important . For example, if the composite material needs to achieve high impact resistance, cotton wool or canvas can be used as a filler, and asbestos or other minerals can be used as a filler to achieve good heat resistance and electrical resistance.

However, in general, the decomposable polymer used is often a hydrophobic substance, and the filler used is a hydrophilic substance, so that the composite material often has poor compatibility and causes mechanical properties to fail to achieve the desired target.

Therefore, how to make a biodegradable composite material that does not pollute the environment and improve the compatibility of the composite material is an urgent problem to be solved.

In view of the problems of the prior art, in order to be able to solve the problem, the inventors have proposed a biodegradable composite material and a manufacturing method thereof based on years of research and development and many practical experiences, as an implementation method for improving the above disadvantages. in accordance with.

In view of the above, an object of the present invention is to provide a biodegradable composite material and a method for fabricating the same, which solve the problems of the above-mentioned plastic contaminated environment and poor compatibility of composite materials.

According to the object of the present invention, a biodegradable composite material comprising: a rubber compound which is kneaded by at least two decomposable polymers, the weight of the rubber compound is 60% by weight of the composite material. ~90% wt; a compatibilizer having a weight of 5% by weight to 15% by weight of the composite material; The organic filler has a weight of 10% by weight to 40% by weight based on the weight of the composite material.

In addition, the present invention further provides a method for preparing a biodegradable composite material, which comprises the steps of first providing a gel, a compatibilizing agent and an organic filler, and then the gel, the compatibilizing agent and the organic filling. The kneading process is carried out to obtain a mixture, and finally the mixture is subjected to a processing procedure to prepare a masterbatch or a molded article of the biodegradable composite.

For a better understanding and understanding of the technical features and the efficacies of the present invention, the preferred embodiments and the detailed description are as follows.

11~13‧‧‧Step process

1 is a flow chart of the steps of the method for preparing the biodegradable composite material of the present invention; and FIG. 2A is a tensile strength analysis of the PLA/PCL composite material with different PCL contents added to the biodegradable composite material of the present invention. Figure 2B is an analysis of the elongation of different PCL content PLA/PCL composites for the biodegradable composite of the present invention; Figure 3A is the addition of different woods for the biodegradable composite of the present invention. Tensile strength analysis chart of powder content PLA/PCL (30wt%) composite material; and 3B figure is the extension of different wood powder content PLA/PCL (30wt%) composite material for biodegradable composite material of the present invention Rate analysis chart;

Hereinafter, the bio-separable according to the preferred embodiment of the present invention will be described with reference to the related drawings. For the sake of understanding, the same elements in the following embodiments are denoted by the same reference numerals.

Please refer to FIG. 1 , which is a flow chart of the steps of the method for preparing the biodegradable composite material of the present invention. In the figure, this method will be explained by the following steps:

Step 11: providing a gel, a compatibilizer and an organic filler.

Wherein, the gel is a mixture of decomposable plastics, and the weight thereof is 60% wt% to 90% by weight of the composite material, and the gel may be a mixture of polylactic acid (PLA) and polycaprolactone (PCL).

The weight of the compatibilizer is from 5% by weight to 15% by weight based on the weight of the composite. The compatibilizer is a copolymer of the gel and acrylic acid (AA) or maleic anhydride (MA).

The organic filler has a weight of 10% by weight to 40% by weight based on the weight of the composite material, and the organic filler may be wood powder.

Step 12: The gelatin, the compatibilizer and the organic filler are subjected to a kneading procedure to obtain a mixture.

Among them, the kneading program can further utilize a mixing device such as a Buss mixer, a 10,000 horsepower mixer, a twin screw extruder, a force mixer, a pressure mixer, a roller or a reaction tank.

Step 13: The mixture is subjected to a processing procedure to obtain a masterbatch or a molded article of the composite material.

Among them, the processing program includes extrusion type, injection molding, hot press molding, hollow formation Type or foam molding to form a masterbatch or molded article of the biodegradable composite.

In one embodiment, the gel is made of polylactic acid (PLA) and polycaprolactone (PCL), and the compatibilizer is a combination of polylactic acid (PLA) and polycaprolactone (PCL). The copolymer of maleic anhydride (MA) is carried out, and the organic filler is carried out with wood flour. The mechanical properties of the polylactic acid and polycaprolactone blends of different contents are analyzed below.

Please refer to FIG. 2A, which is a tensile strength analysis diagram of the addition of different PCL content PLA/PCL composites to the biodegradable composite material of the present invention. In the figure, the curve composed of "●" represents the curve of the PCL tensile strength of different contents of PLA/PCL composite. It is observed from the figure that as the content of PCL increases, the tensile strength decreases. The tensile strength of this decline can be attributed to the fact that the structure of the PCL itself is less strong, so as the content of PCL increases, the factor that the composite cannot support stress and strain migration also increases.

Please refer to FIG. 2B, which is an elongation analysis diagram of the addition of different PCL content PLA/PCL composite materials to the biodegradable composite material of the present invention. In the figure, the curve composed of "●" represents the curve of PCL elongation of different contents of PLA/PCL composite. It is observed from the figure that as the content of PCL increases, the elongation decreases. The elongation of this decay can be attributed to the fact that the structure of the PCL itself is less intense, so as the content of PCL increases, the factors that prevent the composite from supporting stress and strain migration also increase.

From the results of Figures 2A and 2B, it is found that the composite is most suitable. The content should be controlled below 30 wt%. Otherwise, the lower structural strength of PLA can not support the stress migration of PCL, which easily leads to phase separation of the composite and affects the mechanical properties of the composite.

In this embodiment, the gel is carried out in a ratio of polycaprolactone (PCL) to polylactic acid (PLA) of 30%, and the compatibilizer is polylactic acid (PLA) and polycaprolactone (PCL). The gelatin grafted maleic anhydride (MA) copolymer (PLA/PCL-g-MA) is used, and the organic filler is implemented by wood powder. The following will add different content of wood powder and added phase to the composite material. Whether the agent is used for mechanical properties analysis.

Please refer to FIG. 3A, which is a tensile strength analysis diagram of the PLA/PCL (30 wt%) composite material with different wood powder content added to the biodegradable composite material of the present invention. In the figure, the curve composed of "○" represents PLA/PCL (30 wt%) of ungrafted maleic anhydride (MA) and the wood powder content of 0 wt%, 10 wt%, 20 wt%, 30 wt% and 40 wt% tensile. The curve of the intensity, the curve composed of "●" represents the PLA/PCL (30 wt%) of the grafted maleic anhydride (MA) and the wood powder content of 0 wt%, 10 wt%, 20 wt%, 30 wt% and 40 wt% tensile The curve of intensity.

It can be observed from the figure that the tensile strength of PLA/PCL (30 wt%) to which grafted maleic anhydride is added is remarkably higher than the tensile strength of PLA/PCL (30 wt%) to which no maleic anhydride is added. In addition, in PLA/PCL gel, PLA/PCL (30wt%) without grafted maleic anhydride added wood powder content of 20wt%, and tensile strength of grafted maleic anhydride in PLA/PCL (30wt%) Compared with the strength curve, the degree of decrease in tensile strength is slightly slowed down. This is because PLA/PCL (30wt%) itself contains a hydrophobic group, and the wood powder itself contains a hydrophilic group. When the two are mixed, the compatibility is not Good, leading to a slight decrease in the tensile strength curve.

The PLA/PCL (30 wt%) grafted with maleic anhydride has both a hydrophobic group and a hydrophilic group, so after PLA/PCL (30 wt%) to which maleic anhydride (MA) is added, PLA/PCL ( 30wt%) contains a hydrophobic group in the gel, which can interact with the hydrophobic group in the PLA/PCL (30wt%) grafted with maleic anhydride (MA), while the hydrophilic group in the wood powder can be grafted with maleic anhydride ( The hydrophilic group in PLA/PCL (30wt%) of MA) thus produces a chain linkage, so that the compatibility of PLA/PCL (30wt%) of grafted maleic anhydride (MA) is increased and the tensile strength is also Enhanced.

Please refer to FIG. 3B, which is an analysis of the elongation of the biodegradable composite material of the present invention with different wood powder content PLA/PCL (30 wt%) composite materials. In the figure, the curve composed of "○" represents an extension of PLA/PCL (30 wt%) of ungrafted maleic anhydride (MA) and wood powder content of 0 wt%, 10 wt%, 20 wt%, 30 wt% and 40 wt%. The curve of the rate, the curve composed of "●" represents the extension of PLA/PCL (30wt%) of ungrafted maleic anhydride (MA) and wood powder content of 0wt%, 10wt%, 20wt%, 30wt% and 40wt%. The curve of the rate. It can be observed from the figure that the elongation of PLA/PCL (30 wt%) to which grafted maleic anhydride is added is remarkably higher than that of PLA/PCL (30 wt%) to which no grafted maleic anhydride is added. Since PLA/PCL (30% by weight) itself contains a hydrophobic group, and the wood powder itself contains a hydrophilic group, when the two are mixed, the compatibility is poor.

The PLA/PCL (30 wt%) grafted with maleic anhydride has both a hydrophobic group and a hydrophilic group, so after PLA/PCL (30 wt%) to which maleic anhydride (MA) is added, PLA/PCL ( 30wt%) contains a hydrophobic group in the gel, which can interact with the hydrophobic group in the PLA/PCL (30wt%) grafted with maleic anhydride (MA), while the hydrophilic group in the wood powder can be grafted with maleic anhydride ( MA) of the pro-PLA/PCL (30wt%) The water-based action, thus producing a chain, results in an increase in the compatibility of the PLA/PCL (30% by weight) of the grafted maleic anhydride (MA) and an increase in the elongation.

From the results of Figures 3A and 3B, the tensile strength and elongation decreased with the increase of wood flour content. The strength property of this decay can be attributed to the irregular shape of the wood powder, and the mechanical properties of the composite material are reduced because the wood powder cannot provide PLA/PCL (30wt%) to support the stress migration, but under different wood powder content. In the composite material, after adding the grafted maleic anhydride (MA) PLA/PCL (30 wt%), it was found that the effect of adding PLA/PCL (30 wt%) grafted with maleic anhydride after the wood powder content was 10 wt% Gradually presented, so the tensile strength curve is above 20% by weight of wood flour, and the trend of its decline tends to be slow. This phenomenon is not contributed by the grafted maleic anhydride, but the hydrophilic group in the wood powder reacts with the hydrophilic group in the PLA/PCL (30wt%) of the grafted maleic anhydride (MA) to increase the wood powder and PLA/ The interface of PCL (30 wt%) is followed by force. This phenomenon can be attributed to the fact that before the grafting of maleic anhydride (MA), although the wood powder is added to the composite material, the movement of the molecular bond is not limited, and the deformation of the PLA/PCL (30wt%) substrate is not easy. . However, after PLA/PCL (30wt%)/wood flour composite grafted with MA, the interface is bonded, and the deformation of the composite is affected by wood powder and PLA/PCL (30wt%)-g-MA. The deformation is limited, so that the elongation is lowered.

In summary, in the composite materials with different PCL content, it is found that the tensile strength curve decreases more obviously after the PCL content is 30 wt%, which is due to the fact that the composite material is easily separated by phase separation. Add wood powder to the present invention, and upgrade PLA/PCL (30wt%) to PLA/PCL (30wt%)-g-AA to increase The interfacial force of PLA/PCL (30wt%) and wood flour. Due to the hydrophilic group of the wood powder in the gel, it can react with the MA functional group in PLA/PCL (30 wt%)-g-MA, thereby causing a chain reaction.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

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Claims (6)

A method for preparing a biodegradable composite, comprising the steps of: providing a gel, a compatibilizer and an organic filler, wherein the gel is polylactic acid (PLA) and polycaprolactone ( a mixture of PCL), and the ratio of the polycaprolactone (PCL) to the polylactic acid (PLA) is 30% wt or less and more than 0% by weight; the rubber compound, the compatibilizing agent and the organic filler are kneaded The procedure is to obtain a mixture; and the mixture is subjected to a processing procedure to obtain a masterbatch or a molded article of the composite. The preparation method of claim 1, wherein the compatibilizing agent is a copolymer formed by grafting the gel with acrylic acid (AA). The preparation method of claim 1, wherein the compatibilizing agent is a copolymer formed by grafting the gelatin with maleic anhydride (MA). The manufacturing method of claim 1, wherein the organic filler is wood flour. The manufacturing method according to claim 1, wherein the kneading program can further utilize a Buss mixer, a 10,000 horsepower mixer, a twin screw extruder, a force mixer, a pressure mixer, a roller or a reaction tank. Mixing equipment. The production method according to claim 1, wherein the processing program comprises extrusion molding, injection molding, hot press molding, hollow molding or foam molding to prepare a masterbatch or a molded article of the biodegradable composite material. .