CN114717835B - Preparation method of activated sepiolite fiber, PET composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a preparation method of activated sepiolite fiber, PET composite material and a preparation method thereof, wherein 5-15 parts by weight of maleic acid and 8-13 parts by weight of sepiolite fiber are added into 100 parts by weight of deionized water, the mixture is heated to 40-50 ℃, and after ultrasonic dispersion, the mixture is filtered, washed and dried, so that the activity of the sepiolite fiber can be greatly improved, the dispersion filling effect of the sepiolite fiber in a PET matrix is improved, and the mechanical property of the PET composite material is improved.

Description

Preparation method of activated sepiolite fiber, 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, and a PET composite material added with the activated sepiolite fibers and a preparation method thereof.

Background

Polyethylene terephthalate (abbreviated as PET) is the most important variety of thermoplastic polyesters, has low cost and good performance, and is widely used in the fields of electronics, electricity, household appliances, office appliances, automobiles and the like. However, PET materials also have the disadvantages of higher glass transition temperature, slow crystallization speed, poor dimensional stability, large brittleness, poor impact resistance, etc., which limits their application in the field of engineering plastics.

The traditional method for reinforcing the PET material is to add fibers, inorganic fillers and the like into a PET system. Sepiolite fibers, which are a type of natural mineral fiber, are fibrous varieties of sepiolite minerals, known as alpha-sepiolite. Sepiolite is used as a layer chain silicate mineral, a layer of magnesia octahedron is sandwiched between two layers of silicon oxygen tetrahedrons in the structure to form a 2:1 layered structure unit, the four-surface layers are continuous, and the direction of active oxygen in the layers is periodically reversed; the octahedral layers form channels arranged alternately between the upper layer and the lower layer. The orientation of the channels coincides with the fiber axis, allowing water molecules, metal cations, small organic molecules, etc. to enter into it. Sepiolite has better heat resistance, good ion exchange and catalytic properties, and excellent properties such as corrosion resistance, radiation resistance, insulation, heat insulation and the like, and particularly Si-OH in the structure can directly react with organic matters to generate organic mineral derivatives. In its structural units, the siloxy tetrahedra alternate with the magnesia octahedra, with lamellar and chain transition characteristics. Sepiolite has unique physical and chemical properties, high specific surface area (up to 800-900 m/g), large porosity and strong adsorption and catalytic capability.

The current sepiolite has wide application fields, and the sepiolite subjected to 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 industries 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 drilling high-quality slurry 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 the filling effect is not ideal due to the unique structure of the sepiolite fiber, 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 foregoing, it is desirable to provide a process for preparing activated sepiolite fibers, PET composites and methods for preparing the same. 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 purpose, the present invention adopts the following technical effects:

the invention firstly provides a preparation method of activated sepiolite fiber, 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 ℃, performing ultrasonic dispersion, filtering, washing with water, and drying to obtain the activated sepiolite fibers.

The invention utilizes the characteristic of strong adhesion between sepiolite layers or fiber bundles, and utilizes special weak acid maleic acid to treat 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 fiber, the ultrasonic wave can properly dissociate the sepiolite fiber so as to facilitate the sepiolite fiber to be more uniformly dispersed in the matrix resin, and the parameter of ultrasonic dispersion is not particularly limited and can be adjusted according to the requirement, but because the ultrasonic frequency is too high, the sepiolite fiber can be damaged, so that the mechanical property of the sepiolite fiber can be affected to a certain extent, therefore, in some specific embodiments of the invention, the preferred parameter of ultrasonic dispersion is as follows: 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 any sepiolite fiber having a length within a range of conventional lengths in the art may be used, and it is preferable that the length of the sepiolite fiber is 10 to 15mm in some embodiments of the present invention for better prominence of the activation effect.

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 fiber, 0.2-0.5 part of antioxidant 1098, 0.2-0.5 part of antioxidant 168 and 2-3 parts of white oil according to parts by weight.

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

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

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

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 ℃, performing ultrasonic dispersion, filtering, washing with water, and drying to obtain the activated sepiolite fibers.

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

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

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

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

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

It is understood that the extrusion process of the twin-screw extruder belongs to a conventional means for processing polymer materials in the art, and the process parameters such as temperature, rotation speed and the like can be adjusted according to the differences of matrix resin and auxiliary agent, so the extrusion process is not particularly limited. 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:

the sepiolite fiber is activated by using the special weak acid maleic acid to treat the sepiolite fiber by utilizing strong adhesion force between sepiolite layers or fiber bundles, so that the sepiolite has proper pore diameter and high specific surface area, and the activity of the sepiolite fiber 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 fiber has 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 fiber in a PET matrix.

Detailed Description

In order that the invention may be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments that are illustrated below. 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.

Specific information on the matrix resin and the auxiliaries used in the following examples and comparative examples is as follows:

PET has an intrinsic viscosity of 1.0dL/g and is manufactured by DuPont, U.S. and sold under the trademark PET935;

PTT melt index 1.8g/10min (230 ℃,2.16 kg), manufacturer is DuPont company, USA, brand T700;

sepiolite fiber length 10mm, manufacturer is Shijia Rui Yuan mineral products Co., ltd;

white oil manufacturers are Shandong Starlong New Material Co., ltd;

the antioxidants are antioxidant 1098 and antioxidant 168, and the manufacturers are all German basf company;

sodium hydroxide and hydrochloric acid manufacturers are Zhengzhou Longda chemical products limited.

The preparation method of the activated sepiolite fiber in the examples 1-4 comprises the following steps: 10 parts by weight of maleic acid and 10 parts by weight of sepiolite fiber were added to 100 parts by weight of deionized water, heated to 40℃and dispersed ultrasonically for 20 minutes at an ultrasonic frequency of 40KHz. Finally filtering, washing with water, drying at normal temperature and preserving.

In the following examples and comparative examples, the "parts", and the like were all parts by weight unless otherwise specified.

Example 1

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 are added into a mixer, uniformly mixed at normal temperature, then added from a main feeding port of a double-screw extruder, and simultaneously 15 parts of activated sepiolite fibers are added from a side feeding port, and the PET composite material is prepared through melting, extrusion and granulating. 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 machine head 260 ℃.

Example 2

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 are added into a mixer, uniformly mixed at normal temperature, then added from a main feeding port of a double-screw extruder, and simultaneously 25 parts of activated sepiolite fibers are added from a side feeding port, and the PET composite material is prepared through melting, extrusion and granulating. 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 head 250 ℃.

Example 3

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 are added into a mixer, after being uniformly mixed at normal temperature, the mixture is added from a main feeding port of a double-screw extruder, and simultaneously 50 parts of activated sepiolite fibers are added from a side feeding port, and the PET composite material is prepared through melting, extrusion and granulating. Wherein, the temperature of each zone of the twin-screw extruder is respectively 1 zone 190 ℃,2 zone 210 ℃, 3 zone 230 ℃, 4 zone 240 ℃, 5 zone 250 ℃ and machine head 250 ℃.

Example 4

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 are added into a mixer, after being uniformly mixed at normal temperature, the mixture is added from a main feeding port of a double-screw extruder, and simultaneously 35 parts of activated sepiolite fibers are added from a side feeding port, and the PET composite material is prepared through melting, extrusion and granulating. 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 head 250 ℃.

Example 5

The preparation of the activated sepiolite fiber in this example was: 5 parts by weight of maleic acid and 13 parts by weight of sepiolite fiber are added to 100 parts by weight of deionized water, heated to 45 ℃, and dispersed for 15 minutes by ultrasonic waves with the ultrasonic frequency of 20KHz. Finally filtering, washing with water, drying at normal temperature and preserving.

The other steps were the same as in example 4 to prepare a PET composite material.

Example 6

15 parts by weight of maleic acid and 8 parts by weight of sepiolite fiber are added into 100 parts by weight of deionized water, and the mixture is heated to 50 ℃ and dispersed for 10 minutes by ultrasonic waves with the ultrasonic frequency of 30KHz. Finally filtering, washing with water, drying at normal temperature and preserving.

The other steps were the same as in example 4 to prepare a PET composite material.

Comparative example 1

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 are added into a mixer, after being uniformly mixed at normal temperature, the mixture is added from a main feeding port of a double-screw extruder, and simultaneously 35 parts of sepiolite fibers (not activated) are added from a side feeding port, and the PET composite material is prepared through melting, extrusion and granulating. 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 head 250 ℃.

Comparative example 2

(1) 10 parts by weight of sodium hydroxide is slowly dissolved in 100 parts by weight of deionized water, 10 parts by weight of sepiolite fiber is added, the mixture is heated to 40 ℃, and the mixture is subjected to ultrasonic dispersion for 20 minutes, wherein the ultrasonic frequency is 40KHz. Finally filtering, washing with water, drying at normal temperature and preserving.

(2) Adding 100 parts of PET, 50 parts of PTT (polytrimethylene terephthalate) 50 parts, 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 activated sepiolite fibers in the step (1) from a side feeding port, and carrying out melting, extrusion and granulating to obtain the PET composite material. 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 250 ℃ of the machine head.

Comparative example 3

(1) 10 parts by weight of concentrated hydrochloric acid (mass fraction 20%) was slowly added to 100 parts by weight of deionized water, and 10 parts by weight of sepiolite fiber was then added, heated to 40 ℃ and dispersed for 20 minutes with ultrasound at 40KHz. Finally filtering, washing with water, drying at normal temperature and preserving.

(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 feeding port of a double-screw extruder, simultaneously adding 35 parts of activated sepiolite fibers in the step (1) from a side feeding port, and carrying out melting, extrusion and granulating 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 head 250 ℃.

Test case

The PET composites prepared in examples 1-4 and comparative examples 1-3 were subjected to performance-related tests, respectively, and the results are shown in Table 1:

table 1 results of PET composite Performance test

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

flexural strength was measured according to ASTM D790 (flexural speed 1.25 mm/min);

the notched Izod impact performance was tested according to ASTM D256;

the test specimens were injection molded using ASTM standards, with spline dimensions (length. Times. Width. Times. Thickness) of tensile splines (dumbbell) of 170 mm. Times.13 mm. Times.3.2 mm, respectively;

bending the spline 127mm by 13mm by 3.2mm;

the notch impact bars were 127mm by 13mm by 3.2mm, V-notch with a notch depth of 1/5.

As can be seen from the test results in Table 1, the tensile strength, bending strength and impact resistance of the PET composite material can be obviously improved by adopting special maleic acid to activate the sepiolite fiber, and the sepiolite fiber has proper pore diameter and higher specific surface area due to the activation of the sepiolite fiber by maleic acid, so that the activated sepiolite fiber has high activity and excellent dispersion filling effect.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (6)

1. A method for preparing activated sepiolite fibers, comprising the steps of:

and 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 ℃, performing ultrasonic dispersion, filtering, washing with water, and drying to obtain activated sepiolite fibers, wherein the length of the sepiolite fibers is 10-15 mm.

2. The method for preparing activated sepiolite fibers according to claim 1, characterized in that 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. A PET composite material, which is characterized by being prepared from 100 parts of PET, 10-50 parts of PTT, 15-50 parts of the activated sepiolite fiber according to any one of claims 1-2, 0.2-0.5 part of antioxidant 1098, 0.2-0.5 part of antioxidant 168 and 2-3 parts of white oil according to parts by weight.

4. The PET composite of claim 3, wherein the PET has an intrinsic viscosity of 0.5-2dL/g.

5. The PET composite of claim 3, wherein the PTT has a melt index of 1 to 5g/10min at 230 ℃ and 2.16 Kg.

6. A method of producing a PET composite material according to any one of claims 3 to 5, comprising the steps of:

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

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