CN114717835A - Preparation method of activated sepiolite fibers, PET composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a preparation method of activated sepiolite fibers, a PET composite material and a preparation method thereof, wherein the preparation method of the activated sepiolite fibers comprises the steps of adding 5-15 parts by weight of maleic acid and 8-13 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 40-50 ℃, carrying out ultrasonic dispersion, filtering, washing and drying, and can greatly improve the activity of the sepiolite fibers, thereby improving the dispersion filling effect of the sepiolite fibers in a PET matrix and improving the mechanical property of the PET composite material.

Description

Preparation method of activated sepiolite fibers, PET composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a preparation method of activated sepiolite fibers, a PET composite material added with the activated sepiolite fibers and a preparation method of the PET composite material.

Background

Polyethylene terephthalate (PET for short) is the most important type of thermoplastic polyester, has low cost and good performance, and is widely applied to the fields of electronics, electrical, home appliances, office appliances, automobiles and the like. However, the PET material has the disadvantages of high glass transition temperature, slow crystallization speed, poor dimensional stability, high brittleness, poor impact resistance and the like, which limits the application of the PET material in the field of engineering plastics.

The traditional method for reinforcing the PET material comprises the modes of adding fibers, inorganic fillers and the like in a PET system. Sepiolite fiber, a natural mineral fiber, is a fibrous variant of sepiolite mineral, known as α -sepiolite. Sepiolite is used as a layer chain silicate mineral, a layer of magnesium-oxygen octahedron is sandwiched between two layers of silicon-oxygen tetrahedron in the structure to form a 2: 1 type layered structure unit, the tetrahedron layer of the sepiolite is continuous, and the direction of active oxygen in the layer is periodically inverted; the octahedral layers form channels arranged alternately in the upper and lower layers. The orientation of the channels is aligned with the fiber axis, allowing water molecules, metal cations, small organic molecules, etc. to enter therein. The sepiolite has good heat resistance, good ion exchange and catalysis characteristics, excellent characteristics of corrosion resistance, radiation resistance, insulation, heat insulation and the like, and particularly, Si-OH in the structure of the sepiolite can directly react with organic matters to generate organic mineral derivatives. In the structural unit, silicon-oxygen tetrahedrons and magnesium-oxygen octahedrons are mutually alternated, and have the transition characteristics of layers and chains. The sepiolite has unique physical and chemical properties, high specific surface area (up to 800-900m/g), large porosity and strong adsorption and catalysis capabilities.

At present, the application field of sepiolite is very wide, and the sepiolite after a series of treatments such as purification, superfine processing, modification and the like can be used as an adsorbent, a purifying agent, a deodorant, a reinforcing agent, a suspending agent, a thixotropic agent, a filler and the like to be applied to the industrial aspects such as water treatment, catalysis, rubber, coating, chemical fertilizer, feed and the like. In addition, the sepiolite has better salt resistance and high temperature resistance, so that the sepiolite can be used as a high-quality drilling mud raw material for petroleum drilling, geothermal drilling and the like.

The sepiolite fiber is added into a PET system to improve the mechanical strength of the PET material, but due to the unique structure of the sepiolite fiber, the filling effect is not ideal, the reinforcing effect on the PET material is limited, and the application in the field with high mechanical property requirements cannot be met.

Disclosure of Invention

In view of the above, the present invention needs to provide a preparation method of activated sepiolite fiber, a PET composite material and a preparation method thereof. The preparation method of the activated sepiolite fiber can obviously improve the activity of functional groups on the surface of the sepiolite fiber, increase the specific surface area of the sepiolite fiber, and obviously improve the filling effect of the sepiolite fiber in the composite material, thereby obviously improving the tensile strength, the bending strength and the impact strength of the cavity PET composite material.

In order to achieve the above object, the present invention adopts the following technical effects:

the invention firstly provides a preparation method of activated sepiolite fibers, which comprises the following steps:

adding 5-15 parts by weight of maleic acid and 8-13 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 40-50 ℃, ultrasonically dispersing, filtering, washing and drying to obtain the activated sepiolite fibers.

The invention utilizes the characteristic of strong binding force between sepiolite layers or fiber bundles and utilizes special weak acid maleic acid to treat the sepiolite fibers, so that the sepiolite fibers have proper pore diameter and high specific surface area, and the activity of the sepiolite fibers is greatly increased.

Further, in the activation process of the sepiolite fibers, the ultrasonic waves can appropriately dissociate the sepiolite fibers so as to facilitate the sepiolite fibers to be more uniformly dispersed in the matrix resin, the parameters of ultrasonic dispersion are not particularly limited and can be adjusted as required, but the sepiolite fibers may be damaged due to too high ultrasonic frequency, so as to have a certain influence on the mechanical properties of the sepiolite fibers, and therefore, in some specific embodiments of the present invention, it is preferable that the parameters of ultrasonic dispersion specifically are: the ultrasonic frequency is 20-40 KHz, and the ultrasonic time is 10-20 min.

Further, the length of the sepiolite fiber is not particularly limited, and the sepiolite fiber in the conventional length range in the art can be used, and for better prominent activation effect, it is preferable that, in some specific embodiments of the present invention, the length of the sepiolite fiber is 10 to 15 mm.

The invention also provides a PET composite material which is prepared from 100 parts of PET, 10-50 parts of PTT, 15-50 parts of activated sepiolite fibers, 0.2-0.5 part of antioxidant 1098, 0.2-0.5 part of antioxidant 168 and 2-3 parts of white oil in parts by weight.

Because the activated sepiolite fibers have proper pore diameter and high specific surface, the activity of the sepiolite fibers is greatly enhanced, so that the dispersion filling effect of the sepiolite fibers in a PET matrix is improved, and the tensile strength, the bending strength and the impact strength of the PET composite material can be obviously improved.

Further, the PET and PTT described in the present invention are not particularly limited, and any of such resins conventionally used in the art may be used, and in some embodiments of the present invention, the intrinsic viscosity of the PET is from 0.5 to 2 dL/g.

The melt index of the PTT under the conditions of 230 ℃ and 216kg is 1-5 g/10 min.

Further, the preparation method of the activated sepiolite fiber specifically comprises the following steps: adding 5-15 parts by weight of maleic acid and 8-13 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 40-50 ℃, ultrasonically dispersing, filtering, washing and drying to obtain the activated sepiolite fibers.

Further, the parameters of the ultrasonic dispersion specifically include: the ultrasonic frequency is 20-40 KHz, and the ultrasonic time is 10-20 min.

Further, the length of the sepiolite fiber is 10-15 mm.

The invention further provides a preparation method of the PET composite material, which comprises the following steps:

fully and uniformly mixing PET, PTT, an antioxidant 1098, an antioxidant 169 and white oil according to the weight part ratio to obtain a uniform mixed material;

and adding the mixed material from a main feeding port of a double-screw extruder, adding the activated sepiolite fibers from a side feeding port according to the proportion, and carrying out melting, extrusion and grain cutting to obtain the PET composite material.

It is understood that the extrusion process of the twin-screw extruder is a conventional means for processing polymer materials in the art, and the process parameters such as temperature, rotation speed, etc. can be adjusted according to the base resin and the additives, and thus, there is no particular limitation. In some embodiments of the invention, the processing temperature of the twin screw extruder is 180-260 ℃.

Compared with the prior art, the invention has the following beneficial effects:

according to the method, the sepiolite fibers are activated by using special weak acid maleic acid due to the strong binding force among sepiolite layers or fiber bundles, so that the sepiolite has a proper pore diameter and a high specific surface area, and the activity of the sepiolite fibers is greatly improved; ultrasonic dispersion is adopted, and ultrasonic waves are utilized to dissociate sepiolite fibers, so that the sepiolite fibers have more excellent dispersibility and filling property.

The activated sepiolite fibers have excellent activity, and the tensile strength, the bending strength and the impact strength of the PET composite material can be obviously improved by filling the activated sepiolite fibers in a PET matrix.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the specific embodiments illustrated. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The specific information of the matrix resin and the auxiliary used in the following examples and comparative examples is as follows:

PET has an intrinsic viscosity of 1.0dL/g, and was manufactured by DuPont, U.S. Inc., under the designation PET 935;

PTT melt index 1.8g/10min (230 ℃, 2.16kg), manufactured by DuPont, USA, under the designation T700;

the length of sepiolite fiber is 10mm, and the manufacturer is Shijiazhuang Ruiyuan mineral products, Inc.;

the white oil producer is Shandong Xinglong New Material Co., Ltd;

the antioxidant is antioxidant 1098 and antioxidant 168, and the manufacturers are both from Pasteur Germany;

the sodium hydroxide and hydrochloric acid producers are Zhengzhou Longda chemical products Co.

The preparation method of the activated sepiolite fibers in the embodiments 1 to 4 comprises the following steps: adding 10 parts by weight of maleic acid and 10 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 40 ℃, and carrying out ultrasonic dispersion for 20 minutes at the ultrasonic frequency of 40 KHz. And finally, filtering, washing, drying at normal temperature and storing.

In the following examples and comparative examples, "parts", etc. are made by weight unless otherwise specified.

Example 1

Adding 100 parts of PET, 10 parts of PTT, 0.2 part of antioxidant 1098, 0.2 part of antioxidant 168 and 2 parts of white oil into a mixer, uniformly mixing at normal temperature, adding from a main feed inlet of a double-screw extruder, simultaneously adding 15 parts of activated sepiolite fibers from a side feed inlet, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. Wherein the temperature of each zone of the double-screw extruder is respectively 1 zone 180 ℃, 2 zone 200 ℃, 3 zone 220 ℃, 4 zone 240 ℃, 5 zone 250 ℃ and the temperature of a machine head 260 ℃.

Example 2

Adding 100 parts of PET, 20 parts of PTT, 0.5 part of antioxidant 1098, 0.5 part of antioxidant 168 and 3 parts of white oil into a mixer, uniformly mixing at normal temperature, adding from a main feed inlet of a double-screw extruder, simultaneously adding 25 parts of activated sepiolite fibers from a side feed inlet, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. Wherein the temperature of each zone of the double-screw extruder is respectively 1 zone 180 ℃, 2 zone 190 ℃, 3 zone 210 ℃, 4 zone 230 ℃, 5 zone 240 ℃ and the temperature of a machine head is 250 ℃.

Example 3

Adding 100 parts of PET, 30 parts of PTT, 0.3 part of antioxidant 1098, 0.3 part of antioxidant 168 and 3 parts of white oil into a mixer, uniformly mixing at normal temperature, adding from a main feeding port of a double-screw extruder, simultaneously adding 50 parts of activated sepiolite fibers from a side feeding port, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. Wherein the temperature of each zone of the double-screw extruder is respectively 190 ℃ in the 1 zone, 210 ℃ in the 2 zone, 230 ℃ in the 3 zone, 240 ℃ in the 4 zone, 250 ℃ in the 5 zone and 250 ℃ in the head.

Example 4

Adding 100 parts of PET, 50 parts of PTT, 0.5 part of antioxidant 1098, 0.5 part of antioxidant 168 and 2 parts of white oil into a mixer, uniformly mixing at normal temperature, adding from a main feed inlet of a double-screw extruder, simultaneously adding 35 parts of activated sepiolite fibers from a side feed inlet, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. Wherein the temperature of each zone of the double-screw extruder is respectively 1 zone 180 ℃, 2 zone 200 ℃, 3 zone 220 ℃, 4 zone 230 ℃, 5 zone 240 ℃ and the temperature of a machine head is 250 ℃.

Example 5

The preparation of the activated sepiolite fibers in this example was: adding 5 parts by weight of maleic acid and 13 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 45 ℃, and ultrasonically dispersing for 15min at the ultrasonic frequency of 20 KHz. And finally, filtering, washing, drying at normal temperature and storing.

Other steps were the same as in example 4 to obtain a PET composite material.

Example 6

Adding 15 parts by weight of maleic acid and 8 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 50 ℃, and carrying out ultrasonic dispersion for 10min at the ultrasonic frequency of 30 KHz. And finally, filtering, washing, drying at normal temperature and storing.

Other steps were the same as in example 4 to obtain a PET composite material.

Comparative example 1

Adding 100 parts of PET, 50 parts of PTT, 0.5 part of antioxidant 1098, 0.5 part of antioxidant 168 and 2 parts of white oil into a mixer, uniformly mixing at normal temperature, adding the mixture from a main feed inlet of a double-screw extruder, simultaneously adding 35 parts of sepiolite fibers (not activated) from a side feed inlet, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. Wherein the temperature of each zone of the double-screw extruder is respectively 1 zone 180 ℃, 2 zone 200 ℃, 3 zone 220 ℃, 4 zone 230 ℃, 5 zone 240 ℃ and the temperature of a machine head is 250 ℃.

Comparative example 2

(1) Slowly dissolving 10 parts by weight of sodium hydroxide in 100 parts by weight of deionized water, adding 10 parts by weight of sepiolite fibers, heating to 40 ℃, and carrying out ultrasonic dispersion for 20 minutes at the ultrasonic frequency of 40 KHz. And finally, filtering, washing, drying at normal temperature and storing.

(2) And (2) adding 100 parts of PET, 50 parts of PTT50, 0.5 part of antioxidant 1098, 0.5 part of antioxidant 168 and 2 parts of white oil into a mixer, uniformly mixing at normal temperature, adding from a main feeding port of a double-screw extruder, adding 35 parts of the activated sepiolite fibers in the step (1) from a side feeding port, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. The temperatures of each zone of the double-screw extruder are respectively 180 ℃ in the 1 zone, 200 ℃ in the 2 zone, 220 ℃ in the 3 zone, 230 ℃ in the 4 zone, 240 ℃ in the 5 zone and 250 ℃ in the head.

Comparative example 3

(1) Slowly adding 10 parts by weight of concentrated hydrochloric acid (mass fraction is 20%) into 100 parts by weight of deionized water, then adding 10 parts by weight of sepiolite fibers, heating to 40 ℃, and carrying out ultrasonic dispersion for 20 minutes, wherein the ultrasonic frequency is 40 KHz. And finally, filtering, washing, drying at normal temperature and storing.

(2) Adding 100 parts of PET, 50 parts of PTT, 0.5 part of antioxidant 1098, 0.5 part of antioxidant 168 and 2 parts of white oil into a mixer, uniformly mixing at normal temperature, adding from a main feed inlet of a double-screw extruder, simultaneously adding 35 parts of the activated sepiolite fibers in the step (1) from a side feed inlet, and carrying out melting, extrusion and grain cutting to obtain the PET composite material. Wherein the temperatures of the zones of the double-screw extruder are respectively 180 ℃ in the 1 zone, 200 ℃ in the 2 zone, 220 ℃ in the 3 zone, 230 ℃ in the 4 zone, 240 ℃ in the 5 zone and 250 ℃ in the nose.

Test example

The PET composites prepared in examples 1 to 4 and comparative examples 1 to 3 were subjected to respective correlation performance tests, and the results are shown in table 1:

TABLE 1PET composite Performance test results

Note: in Table 1, tensile strength was measured in accordance with ASTM D638 (tensile speed 5 mm/min);

flexural Strength was tested according to ASTM D790 (bending speed 1.25 mm/min);

notched izod impact performance was tested according to ASTM D256;

the test specimens were injection molded using ASTM standards, and the specimen dimensions (length. times. width. times. thickness) were tensile specimen (dumbbell type) of 170 mm. times.13 mm. times.3.2 mm, respectively;

bending a sample bar, 127mm × 13mm × 3.2 mm;

notched impact bars, 127mm by 13mm by 3.2mm, V-notches, notch depth 1/5.

The test results in table 1 show that the sepiolite fiber is activated by the special maleic acid, so that the tensile strength, the bending strength and the impact resistance of the PET composite material can be obviously improved, mainly because the sepiolite fiber is activated by the maleic acid, the sepiolite fiber has a proper pore size and a high specific surface area, and the activated sepiolite fiber has high activity and an excellent dispersion filling effect.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A preparation method of activated sepiolite fibers is characterized by comprising the following steps:

adding 5-15 parts by weight of maleic acid and 8-13 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 40-50 ℃, ultrasonically dispersing, filtering, washing and drying to obtain the activated sepiolite fibers.

2. The process for the preparation of activated sepiolite fibers according to claim 1 wherein the parameters of the ultrasonic dispersion are in particular: the ultrasonic frequency is 20-40 KHz, and the ultrasonic time is 10-20 min.

3. The method for preparing the activated sepiolite fiber according to claim 1, wherein the length of the sepiolite fiber is 10 to 15 mm.

4. The PET composite material is characterized by being prepared from 100 parts of PET, 10-50 parts of PTT, 15-50 parts of activated sepiolite fibers, 0.2-0.5 part of antioxidant 1098, 0.2-0.5 part of antioxidant 168 and 2-3 parts of white oil in parts by weight.

5. The PET composite of claim 4 wherein the intrinsic viscosity of the PET is from 0.5 to 2 dL/g.

6. The PET composite of claim 4 wherein the PTT has a melt index of 1 to 5g/10min at 230 ℃ and 216 kg.

7. The PET composite material according to claim 4, wherein the preparation method of the activated sepiolite fibers comprises the following specific steps: adding 5-15 parts by weight of maleic acid and 8-13 parts by weight of sepiolite fibers into 100 parts by weight of deionized water, heating to 40-50 ℃, ultrasonically dispersing, filtering, washing and drying to obtain the activated sepiolite fibers.

8. The PET composite material according to claim 7, characterized in that the parameters of ultrasonic dispersion are, in particular: the ultrasonic frequency is 20-40 KHz, and the ultrasonic time is 10-20 min.

9. The PET composite material of claim 7 wherein the sepiolite fibers have a length of 10 to 15 mm.

10. A process for the preparation of a PET composite material according to any one of claims 4 to 9, characterized in that it comprises the following steps:

fully and uniformly mixing PET, PTT, an antioxidant 1098, an antioxidant 169 and white oil according to the weight part ratio to obtain a uniform mixed material;

and adding the mixed material from a main feeding port of a double-screw extruder, adding the activated sepiolite fibers from a side feeding port according to the proportion, and carrying out melting, extrusion and grain cutting to obtain the PET composite material.