CN104672825A - Polybutylene adipate-terephthalate/nanocellulose degradable composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a polybutylene adipate-terephthalate/nano-cellulose degradable composite material and a preparation method thereof. The composite material comprises the following raw materials in parts by weight: 99.0-99.9 parts of polybutylene adipate terephthalate and 0.1-1.0 part of nano-cellulose; in the composite material, polybutylene adipate terephthalate is used as a matrix material, nanocellulose is used as a dispersion phase, and the dispersion phase is uniformly dispersed in the matrix material. The degradable composite material prepared by the invention has good strength and toughness, and the preparation method is simple and easy to implement, is beneficial to expanding the application field of the polybutylene adipate terephthalate, can be applied to the fields of packaging materials, home decoration, automobile interior decoration, agricultural mulching films and the like, and can moderate the ecological pressure caused by white pollution.

Description

A kind of polybutylene adipate terephthalate/nanometer cellulose degradable composite material and preparation method thereof

technical field

The invention relates to the field of degradable polymer composite materials. More specifically, it relates to a polybutylene adipate terephthalate/nanocellulose degradable composite material and a preparation method thereof.

Background technique

Due to the comprehensive excellent properties of plastic materials, it is widely used in industry, agriculture and people's daily life. However, while various plastic products provide people with great convenience, the environmental pollution caused by their disposal is also becoming more and more serious. Therefore, in recent years, biodegradable plastics have received more and more attention, and are considered to be an effective way to solve plastic waste pollution, and now China, the United States, Japan and Europe have realized the industrial production of biodegradable plastics, Corresponding products are also available. Among the synthetic biodegradable materials currently in industrial production, polybutylene adipate terephthalate (PBAT) is a copolyester that has both the biodegradability of aliphatic polyester and the mechanical properties of aromatic polyester. Good ductility and elongation at break, as well as good heat resistance and impact properties, are very conducive to processing and forming. Its industrial products have stable performance in a dry environment, can be stored and used for a long time, and can be completely biodegraded into carbon dioxide and water in soil, seawater and compost after being discarded, without causing environmental pollution. It is precisely because of the comprehensive excellent properties of polybutylene adipate terephthalate that it can be widely used in packaging fields, such as packaging films, lunch boxes, cosmetic bottles and pharmaceutical bottles, electronic device packaging, etc.; disposable appliances , such as disposable catering utensils, disposable medical supplies, etc.; agricultural fields, such as agricultural films, pesticide and fertilizer slow-release materials, etc., and biomedical polymer fields. However, due to the presence of the aromatic segment reduces the degradation rate of the copolyester, while the low tensile strength also limits the application of the material in the field of higher mechanical properties, so in order to improve the polybutylene adipate terephthalate For the comprehensive properties of glycol esters, it is particularly important to use blending methods to modify them.

Natural plant fiber itself has the advantages of light weight, high strength, good toughness, and biodegradability. The research on cellulose-based modification is currently an emerging and active field. The energy consumption required for the preparation of the cellulose-modified polymer composite material is lower, and the emission of harmful gases that may occur is also reduced. CN104194288A discloses a kind of modified polyadipate/butylene terephthalate composite material containing Zizania officinalis shell fiber and its preparation method. The mechanical properties of the obtained composite material are improved to a certain extent, but the invention effectively improves the At the same time, the tensile strength causes a decrease in the elongation at break, which destroys the good toughness of the material itself. Due to the high requirements for the tolerance and flexibility of the material in the field of packaging plastics, it hinders its use in the industry. Large-scale applications in production. At the same time, the preparation process of this invention is relatively complicated, and it is difficult to control the dosage in all aspects from obtaining raw materials to modification and adding coupling agents, antioxidants, heat stabilizers, etc., which greatly increases labor costs. Therefore, it is necessary to make further research and innovative improvements in the selection of raw materials, improvement of process, and improvement of the overall mechanical properties of composite materials.

Compared with traditional cellulose, nanocellulose has the characteristics of huge specific surface area, high purity, high degree of polymerization, high crystallinity, high strength, high Young's modulus, etc., and it shows extremely high Young's modulus in material synthesis. Modulus and strength and other properties, coupled with its light weight, degradability, good biocompatibility and renewable characteristics of biomaterials, make it show great application prospects in high-performance composite materials. At the same time, the surface of nanocellulose contains a large number of high-purity hydroxyl groups, which makes the surface easy to chemically modify to endow the surface with different characteristics, improve its dispersion in hydrophobic matrix materials, and expand the application range of nanocellulose. The potential advantages of nano-new vitamins as reinforced materials have attracted more and more people's attention, and the development of such reinforced materials has important significance in environmental protection and resource protection.

Contents of the invention

An object of the present invention is to provide a polybutylene adipate terephthalate/nanocellulose degradable composite material. As a filler material for polymers, nanocellulose can improve the mechanical properties of polybutylene adipate terephthalate (PBAT), improve toughness without changing the crystallization properties of the material itself, and has very significant social significance.

Another object of the present invention is to provide a preparation method of polybutylene adipate terephthalate/nanometer cellulose degradable composite material.

The present invention mixes polybutylene adipate terephthalate and nano-cellulose to form a novel composite material, and makes nano-cellulose in the matrix of polybutylene adipate terephthalate reach the The uniform dispersion at the nanoscale and the formation of strong interfacial interactions greatly improve the mechanical and thermal properties of the composite material, and the preparation method is simple and feasible, suitable for large-scale promotion.

In order to achieve the above-mentioned first object, the present invention adopts the following technical solutions:

A polybutylene adipate terephthalate/nanometer cellulose degradable composite material, comprising the following raw materials in parts by weight:

Polybutylene adipate terephthalate 99.0-99.9 parts,

Nanocellulose 0.1-1.0 parts;

In the composite material, polybutylene adipate terephthalate is used as a base material, nanocellulose is a dispersed phase, and the dispersed phase is uniformly dispersed in the base material.

Preferably, the weight average molecular weight of the polybutylene adipate terephthalate is 10000-50000 g/mol, and the molar ratio of terephthalic acid to adipic acid is 40:60-60:40.

Preferably, the polybutylene adipate terephthalate has a weight average molecular weight of 14000 g/mol, and a molar ratio of terephthalic acid to adipic acid is 46:54.

Preferably, the nanocellulose has a diameter of 2-1000 nm and a length of 10-100 μm.

Preferably, the nanocellulose is derived from cellulose of natural herbaceous plants or cellulose of natural woody plants.

Among them, nanocellulose with a diameter of 2-1000nm and a length of 10-100 μm has the advantage of its high purity, high Crystallinity, high strength, and ultrafine structure can better improve the interfacial compatibility with the polymer matrix material, and can significantly improve the mechanical properties of the base material with a very small amount of addition.

In order to achieve above-mentioned another object, the present invention adopts following technical scheme:

A method for preparing polybutylene adipate terephthalate/nanocellulose degradable composite material as described above, comprises the steps:

1) Dispersing the nanocellulose in chloroform, the nanocellulose having a solid content of 0.1%-1%, ultrasonically dispersing to obtain a uniformly dispersed suspension A.

2) Polybutylene adipate terephthalate is dissolved in chloroform, and the mass fraction of said polybutylene adipate terephthalate in the solution is 10%-20%, to obtain a uniform solution b.

3) Pour suspension A prepared in step 1) into solution B prepared in step 2), physically stir and mix evenly to obtain blend C.

4) The blend C was mixed with ethanol, purified and vacuum-dried to obtain a polybutylene adipate terephthalate/nanocellulose degradable composite material.

Preferably, in step 1), the ultrasonic dispersion time is 5-15 min, more preferably 8-10 min; the ultrasonic dispersion temperature is 20°C.

Preferably, in step 3), the volume ratio of suspension A to solution B is 1:3-1:8; the temperature of physical stirring is 20°C; the time of physical stirring is 30 minutes.

Preferably, in step 4), the ethanol is absolute ethanol, and the volume ratio of ethanol to blend C is 2.5:1-5:1.

Preferably, in step 4), the temperature range of vacuum drying is 80-100°C; preferably, the temperature of vacuum drying is 85°C.

The beneficial effects of the present invention are as follows:

1. The composite material of the present invention selects two biodegradable materials polybutylene adipate terephthalate and nanocellulose in the selection of raw materials. Polybutylene adipate terephthalate is a general-purpose biodegradable plastic that can be widely popularized and applied. Its preparation process is mature. Butylene glycol formate has good heat resistance, and its heat distortion temperature and product use temperature can exceed 100°C. Nanocellulose is one of the products of nature with abundant yield. As a natural degradable material, it has good mechanical properties.

2. Polybutylene adipate terephthalate and nanocellulose are thermodynamically incompatible two materials. The present invention adjusts process parameters by adjusting the ratio of nanocellulose, and adopts a solvent blending method to make The two materials have good dispersion at the physical level, which greatly improves the compatibility of the two materials.

3. The polybutylene adipate terephthalate/nanocellulose degradable composite material of the present invention has high strength and high toughness at the same time, and the mechanical properties are improved when the amount of nanocellulose is very small The effect is remarkable, so that it has a very wide application prospect in the fields of electronics and sealing.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 shows the graph of tensile strength test data and elongation at break test data of the composite material prepared by the embodiment of the present invention 1-5 and the pure polybutylene adipate terephthalate material prepared by comparative examples .

Fig. 2 (a) shows the transmission electron micrograph of the pure polybutylene adipate terephthalate material prepared in the comparative example of the present invention.

Fig. 2(b) shows a transmission electron micrograph of the polybutylene adipate terephthalate/nanocellulose degradable composite material prepared in Example 1 of the present invention.

Detailed ways

In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

Example 1

1) Disperse 1 part by weight of nanocellulose (NFC) in chloroform, the solid content of nanocellulose is 0.5%, and ultrasonically disperse at 20°C to obtain suspension A. The nanocellulose has a diameter of 2-1000nm and a length of 10-100μm.

2) 99 parts by weight of polybutylene adipate terephthalate (PBAT) are dissolved in chloroform to obtain solution B, and the mass fraction of polybutylene adipate terephthalate in the solution is 15 %.

3) Pour all suspension A into solution B at 20°C, and the volume ratio of A to B is 1:3.

4) After stirring for 30 minutes to mix evenly, use 5 times the volume of ethanol to purify, and obtain the polybutylene adipate terephthalate/nanocellulose degradable composite material after vacuum drying.

Example 2

1) Disperse 0.8 parts by weight of nanocellulose in chloroform, the solid content of nanocellulose is 1%, and ultrasonically disperse at 20°C to obtain suspension A. The nanocellulose has a diameter of 2-1000nm and a length of 10- 100 μm.

2) 99.2 parts by weight of polybutylene adipate terephthalate was dissolved in chloroform to obtain solution B, and the mass fraction of polybutylene adipate terephthalate in the solution was 20%.

3) Pour all the suspension into solution B at 20°C, at this time the volume ratio of A to B is 1:8.

4) After stirring for 30 minutes to mix evenly, use 4 times the volume of ethanol to purify, and obtain the polybutylene adipate terephthalate/nanocellulose degradable composite material after vacuum drying.

Example 3

1) Disperse 0.6 parts by weight of nanocellulose in chloroform, the solid content of nanocellulose is 0.6%, and ultrasonically disperse at 20°C to obtain suspension A. The nanocellulose has a diameter of 2-1000nm and a length of 10- 100 μm.

2) 99.4 parts by weight of polybutylene adipate terephthalate was dissolved in chloroform to obtain solution B, and the mass fraction of polybutylene adipate terephthalate in the solution was 10%.

3) Pour all the suspension into solution B at 20°C, at this time the volume ratio of A to B is 1:5.

4) After stirring for 30 minutes to mix evenly, use 4 times the volume of ethanol to purify, and obtain the polybutylene adipate terephthalate/nanocellulose degradable composite material after vacuum drying.

Example 4

1) Disperse 0.4 parts by weight of nanocellulose in chloroform, the solid content of nanocellulose is 0.5%, and ultrasonically disperse at 20°C to obtain suspension A. The nanocellulose has a diameter of 2-1000nm and a length of 10- 100 μm.

2) Dissolving 99.6 parts by weight of polybutylene adipate terephthalate in chloroform to obtain solution B, the mass fraction of polybutylene adipate terephthalate in the solution is 15%.

3) Pour all the suspension into solution B at 20°C, at this time the volume ratio of A to B is 1:8.

4) After stirring for 30 minutes to mix evenly, use 5 times the volume of ethanol to purify, and obtain the polybutylene adipate terephthalate/nanocellulose degradable composite material after vacuum drying.

Example 5

1) Dissolve 0.2 parts by weight of nanocellulose in chloroform, the solid content of nanocellulose is 0.2%, and ultrasonically disperse at 20°C to obtain suspension A. The nanocellulose has a diameter of 2-1000nm and a length of 10- 100 μm.

2) Dissolving 99.8 parts by weight of polybutylene adipate terephthalate in chloroform to obtain solution B, the mass fraction of polybutylene adipate terephthalate in the solution is 20%.

3) Pour all the suspension into solution B at 20°C, at this time the volume ratio of A to B is 1:5.

4) After stirring for 30 minutes to mix evenly, use 3 times the volume of ethanol to purify, and obtain the polybutylene adipate terephthalate/nanocellulose degradable composite material after vacuum drying.

comparative example

The comparative example is pure polybutylene adipate terephthalate without adding any nanocellulose, which is the same batch product as the polybutylene adipate terephthalate in the examples.

The mechanical property test results of Comparative Examples and Examples 1-5 are shown in Table 1 below.

Table 1

It can be seen from the results in the table that by adding a small amount of nanocellulose, the mechanical properties of polybutylene adipate terephthalate have been greatly improved, and the toughness and tensile strength of the composite material are better than The comparison example shows that nanocellulose can improve the mechanical properties of polybutylene adipate terephthalate well. With the increase of nanocellulose content, the elastic modulus, tensile strength, and elongation at break all increased significantly, but when the amount of nanocellulose added reached a certain proportion, the strength and elongation at break of the composite material decreased. slightly down. Analyzing the reason, when the amount of nano-cellulose added can be more uniformly dispersed in the polybutylene adipate terephthalate matrix, when the composite material is subjected to external force, part of the force is transmitted to the cellulose, which increases the The anti-external pressure ability of the material plays a role in strengthening polybutylene adipate terephthalate; and, the nano-cellulose presents a three-dimensional network result in the matrix, and the hydroxyl group and the polyester form an intermolecular force, thereby Increases the toughness of the material. However, when the nanocellulose content is greater than 0.4% and continues to increase, a small amount of nanocellulose begins to agglomerate, so its effect on improving the mechanical properties of PBAT is saturated, so it is observed that the tensile strength and elongation at break of the material are both stabilize, or even decline. But another part of well-dispersed nanocellulose still plays the role of strengthening and toughening in the matrix material.

Accompanying drawing 1 shows the graph drawn according to the data in the table of the composite material prepared by the embodiment 1-5 of the present invention and the pure polybutylene adipate terephthalate material prepared by the comparative example. The figure and the data in the table belong to the same group, so the result review is not repeated here, but the results in the table are displayed in a more intuitive way.

Fig. 2 (a) shows the transmission electron micrograph of the pure polybutylene adipate terephthalate material prepared in the comparative example of the present invention. Fig. 2(b) shows a transmission electron micrograph of the polybutylene adipate terephthalate/nanocellulose degradable composite material prepared in Example 1 of the present invention. As can be seen from the comparison of Fig. 2(a) and Fig. 2(b), the present invention optimizes the composite material prepared by corresponding process parameters by adopting the solvent blending method, and the dispersed phase nanocellulose can be uniformly dispersed in the polyethylene acid butylene terephthalate matrix.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those of ordinary skill in the art can also make It is impossible to exhaustively list all the implementation modes here, and any obvious changes or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims (10)

1. poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material, is characterized in that, comprise the raw material of following parts by weight:

Poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester 99.0-99.9 part,

Nano-cellulose 0.1-1.0 part;

In described matrix material, poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester is body material, and nano-cellulose is disperse phase, and disperse phase is dispersed in body material.

2. poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 1, it is characterized in that: described poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester weight-average molecular weight is 10000-50000g/mol, and terephthalic acid and hexanodioic acid mol ratio are 40:60-60:40.

3. poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 1, it is characterized in that: preferably, described poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester weight-average molecular weight is 14000g/mol, and terephthalic acid and hexanodioic acid mol ratio are 46:54.

4. poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 1, is characterized in that: described nano-cellulose diameter is 2-1000nm, length is 10-100 μm.

5. poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 1, is characterized in that: described nano-cellulose derives from the Mierocrystalline cellulose of natural herbs or the Mierocrystalline cellulose of natural xylophyta.

6. prepare as arbitrary in claim 1-5 as described in the method for poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material, it is characterized in that, comprise the steps:

1) be scattered in chloroform by nano-cellulose, described nano-cellulose solid content is 0.1%-1%, and ultrasonic disperse obtains finely dispersed suspending liquid A.

2) be dissolved in chloroform by poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester, described poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester massfraction is in the solution 10%-20%, obtains homogeneous solution B.

3) by step 1) obtained suspending liquid A pours step 2 into) obtained solution B, mix after physical agitation and obtain blend C.

4) blend C is mixed with ethanol, obtained poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material after purification, vacuum-drying.

7. the preparation method of a kind of poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 6, is characterized in that: step 1) in, the time of ultrasonic disperse is 5-15min, is more preferably 8-10min; The temperature of ultrasonic disperse is 20 DEG C.

8. the preparation method of a kind of poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 6, is characterized in that: step 3) in, the volume ratio of suspending liquid A and solution B is 1:3-1:8; The temperature of physical agitation is 20 DEG C; The time of physical agitation is 30min.

9. the preparation method of a kind of poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 6, it is characterized in that: step 4) in, described ethanol is dehydrated alcohol, and the volume ratio that ethanol mixes with blend C is 2.5:1-5:1.

10. the preparation method of a kind of poly-hexanodioic acid mutual-phenenyl two acid bromide two alcohol ester/nano-cellulose degradable composite material according to claim 6, is characterized in that: step 4) in, vacuum drying temperature range is 80-100 DEG C; Preferably, vacuum drying temperature is 85 DEG C.