CN106380697A - A kind of high modulus low density polypropylene and preparation method thereof - Google Patents

Abstract

The invention discloses a high-modulus low-density polypropylene and a preparation method thereof, wherein the high-modulus low-density polypropylene is prepared from the following components in parts by weight: 81-100 parts of polypropylene and 0.5-15 parts of long glass fiber reinforced polypropylene. The polypropylene and the long glass fiber reinforced polypropylene are uniformly mixed according to a certain proportion, and the polypropylene can be used as high-modulus low-density polypropylene. The invention utilizes the glass fiber with a certain length in the long glass fiber reinforced polypropylene to be dispersed in the polypropylene system, and the glass fiber plays a skeleton role in the polypropylene due to the fact that the length of the glass fiber is reserved as far as possible, so that the mechanical property of the polypropylene is obviously improved, and the density of the polypropylene material is hardly influenced due to the fact that the content of the introduced glass fiber is not more than 6%.

Description

A kind of high modulus low density polypropylene and preparation method thereof

technical field

The invention relates to the technical field of chemical materials, in particular to a polypropylene and a preparation method thereof.

Background technique

Polypropylene has low density, excellent mechanical properties, good resistance to stress cracking, fatigue yield resistance and chemical resistance, and has the advantages of cheap price and easy processing and molding. However, polypropylene has the disadvantage of low flexural modulus, which also limits its application in industry. Therefore, in order to make polypropylene get good application in industry, it must be modified. In order to increase the modulus of modified polypropylene, inorganic mineral powders such as nanoclay and talcum powder are usually added to polypropylene, but the increase of inorganic mineral powder will increase its density; The nucleation and crystallization ability of the nucleating agent can also increase the modulus of polypropylene.

Patent application No. 200910194556.8 discloses a low-density, high-rigidity, high-toughness polypropylene nanocomposite material and its preparation method. By adding a small amount of nanoclay, the flexural modulus of polypropylene can be increased with little increase in density. The patent application number is 201110443064.5 discloses a high transparency, high modulus impact modified polypropylene material and its preparation method, by adding a nucleating agent into two (3,4-dimethyl dibenzylidene) sorbitol (DMDBS), using the nucleating crystallization ability of the nucleating agent to increase the modulus of the PP matrix.

The above methods all have the problem that in order to keep the polypropylene density basically unchanged, the material modulus is not greatly improved, and in order to allow the nanoclay or nucleating agent to be uniformly dispersed in polypropylene, they all need to be melted by a plastic extruder Extrusion granulation increases energy consumption and the risk of deterioration of material secondary heat performance.

Contents of the invention

In order to solve the contradiction between obtaining high modulus and not increasing the density of polypropylene, the invention provides a high modulus low density polypropylene with simple preparation method, low cost and obvious effect and a preparation method thereof.

The technical solution adopted by the present invention to achieve the above object is: a high modulus low density polypropylene made of the following components proportioned by weight:

Polypropylene 81~100 parts

Long glass fiber reinforced polypropylene 0.5~15 parts

Preferably, the polypropylene is homopolypropylene or copolymerized polypropylene or a mixture of homopolypropylene and copolymerized polypropylene in any proportion.

Preferably, the total glass fiber content in the high-modulus low-density polypropylene is 0.2%-6% of the total amount of the system.

Preferably, the high-modulus low-density polypropylene described in the present application further includes processing aids, and the processing aids are one or more of lubricants, antioxidants, light stabilizers, and colorants.

The lubricant is one or more of stearate, polyolefin wax, ethylene bisstearamide, and pentaerythritol stearate.

The antioxidant is one or more of phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

The light stabilizer is one or more of hindered amine light stabilizers, triazine light stabilizers, and benzotriazole light stabilizers.

The colorant is one or more of inorganic pigments and organic pigments.

The stearate is preferably calcium stearate.

The polyolefin wax is preferably polyethylene wax.

The preferred phenolic antioxidant is Antioxidant 1010.

Phosphite antioxidant is preferably antioxidant 168.

Thioester Antioxidant Preferred Antioxidant DSTP

The light stabilizer is preferably American Cytec V703, V680 light stabilizer

The present application also provides the preparation method of above-mentioned high modulus low density polypropylene, specifically comprises the following steps:

(1) Obtain long glass fiber reinforced polypropylene by using known technology;

(2) Obtain processing aid masterbatch by using known technology: mix polypropylene, lubricant, antioxidant, light stabilizer and colorant evenly and melt and extrude granulation through plastic extrusion granulator to obtain processing aid masterbatch grain;

(3) Mix polypropylene, long glass fiber reinforced polypropylene and processing aid masterbatch in a certain proportion to make high modulus low density polypropylene.

Beneficial effects: the present invention utilizes long glass fibers to reinforce polypropylene with a certain length of glass fibers dispersed into the polypropylene system to form a three-dimensional network structure. Since the length of the glass fibers is kept as much as possible, the glass fibers play a role as a skeleton in the polypropylene , significantly improved the mechanical properties of polypropylene. Since the glass fiber content introduced does not exceed 6%, it does not significantly affect the density of the polypropylene material.

detailed description

A high modulus low density polypropylene made from the following components in the weight ratio:

Polypropylene 81~100 parts

Long glass fiber reinforced polypropylene 0.5~15 parts

Preferably, the polypropylene is homopolypropylene or copolymerized polypropylene or a mixture of homopolypropylene and copolymerized polypropylene in any proportion.

Preferably, the total glass fiber content in the high-modulus low-density polypropylene is 0.2%-6% of the total amount of the system.

Preferably, the high-modulus low-density polypropylene described in the present application further includes processing aids, and the processing aids are one or more of lubricants, antioxidants, light stabilizers, and colorants.

The lubricant is one or more of stearate, polyolefin wax, ethylene bisstearamide, and pentaerythritol stearate.

The antioxidant is one or more of phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

The light stabilizer is one or more of hindered amine light stabilizers, triazine light stabilizers, and benzotriazole light stabilizers.

The colorant is one or more of inorganic pigments and organic pigments.

Stearate is preferably calcium stearate, polyolefin wax is preferably polyethylene wax, phenolic antioxidant is preferably antioxidant 1010, phosphite antioxidant is preferably antioxidant 168, and thioester antioxidant is preferably antioxidant Oxygen agent DSTP, light stabilizer preferably American Cytec V703 light stabilizer, V680 light stabilizer.

The preparation method of above-mentioned high modulus low density polypropylene specifically comprises the steps:

(1) Obtain long glass fiber reinforced polypropylene by using known technology;

(2) Obtain processing aid masterbatch by using known technology: mix polypropylene, lubricant, antioxidant, and light stabilizer evenly and melt, extrude and granulate through plastic extrusion granulator to obtain processing aid masterbatch;

(3) Mix polypropylene, long glass fiber reinforced polypropylene and processing aid masterbatch in a certain proportion to make high modulus low density polypropylene.

Long glass fiber reinforced polypropylene can adopt application number 201210288635.7 a kind of long glass fiber reinforced polypropylene composite material, preparation method and its application; application number CN201410033762.1 long glass fiber reinforced polypropylene composite material and its preparation method; etc. known technologies get.

The processing aid masterbatch can use the application number CN201410827389.7, a low-odor, highly dispersed scratch-resistant masterbatch and its preparation method. Refer to its preparation method, and set the extrusion processing temperature according to the melting temperature of polypropylene. The polypropylene, antioxidant, lubricant, light stabilizer, colorant, etc. are mixed uniformly and extruded through an extruder to granulate. It is also possible to adopt the preparation method of granulated antioxidant for plastic processing with application number 200410091120.3, refer to the preparation method, set the extrusion processing temperature according to the melting temperature of the lubricant, and combine the antioxidant, lubricant, light stabilizer, coloring Agents, etc. are mixed evenly and extruded through an extruder to granulate.

Production of processing aid masterbatch: mix powdered polypropylene Z30S 75Kg, calcium stearate 5Kg, polyethylene wax 7.5kg, antioxidant 1010 5kg, antioxidant 168 7.5kg and melt them through a plastic extrusion granulator Extrusion granulation to obtain processing aid masterbatch.

Mix polypropylene, long glass fiber reinforced polypropylene and processing aid masterbatch uniformly according to the proportions of the examples or comparative examples, inject them into standard test specimens by injection molding machine, test the density according to the ISO1183 standard, and test the flexural modulus according to the ISO178 standard .

The long glass fiber reinforced polypropylene adopts the brand LGF PP-40 produced by Dalian Juxing Technology Co., Ltd., and the long glass fiber content is 40%. The short glass fiber reinforced polypropylene adopts the brand PP10 produced by Dalian Juxing Technology Co., Ltd., and the short glass fiber content 30%.

Grade Example 1 Example 2 Example 3 Example 4 Polypropylene Z30S 86 91 95.5 81 long glass fiber reinforced polypropylene LGF PP-40 10 5 0.5 15 Processing Aid Masterbatch 4 4 4 4 Actual glass fiber content 4% 2% 0.2% 6%

Grade Example 5 Example 6 Example 7 Example 8 Polypropylene 7726 86 91 95.5 81 long glass fiber reinforced polypropylene LGF PP-40 10 5 0.5 15 Processing Aid Masterbatch 4 4 4 4 Actual glass fiber content 4% 2% 0.2% 6%

Grade Example 9 Example 10 Example 11 Example 12 Polypropylene Z30S 43 45.5 47.75 40.5 Polypropylene 7726 43 45.5 47.75 40.5 long glass fiber reinforced polypropylene LGF PP-40 10 5 0.5 15 Processing Aid Masterbatch 4 4 4 4 Actual glass fiber content 4% 2% 0.2% 6%

Grade Example 13 Example 14 Example 15 Example 16 Polypropylene Z30S 90 0 99.5 0 Polypropylene 7726 0 95 0 85 long glass fiber reinforced polypropylene LGF PP-40 10 5 0.5 15 Actual glass fiber content 4% 2% 0.2% 6%

Grade Example 17 Example 18 Polypropylene Z30S 45 47.5 Polypropylene 7726 45 47.5 long glass fiber reinforced polypropylene LGFPP40 10 5 Actual glass fiber content 4% 2%

Grade Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Polypropylene Z30S 82.7 89.3 0 0 Polypropylene 7726 0 0 82.7 89.3 Short Glass Fiber Reinforced Polypropylene PP10 (glass fiber content 30%) 13.3 6.7 13.3 6.7 Processing Aid Masterbatch 4 4 4 4 Actual glass fiber content 4% 2% 4% 2%

Grade Comparative example 5 Comparative example 6 Comparative example 7 Comparative example 8 Polypropylene Z30S 41.35 44.65 0 100 Polypropylene 7726 41.35 44.65 0 0 Polypropylene 5029 0 0 100 0 Short Glass Fiber Reinforced Polypropylene PP10 (glass fiber content 30%) 13.3 6.7 0 0 Processing Aid Masterbatch 4 4 0 0 Actual glass fiber content 4% 2% 0 0

Test Results

unit Example 1 Example 2 Example 3 Example 4 density g/ ^cm3 0.940 0.925 0.915 0.951 Flexural modulus MPa 1850 1683 1459 2029

unit Example 5 Example 6 Example 7 Example 8 density g/ ^cm3 0.939 0.925 0.913 0.949 Flexural modulus MPa 1578 1461 1285 1850

unit Example 9 Example 10 Example 11 Example 12 density g/ ^cm3 0.940 0.925 0.914 0.950 Flexural modulus MPa 1730 1580 1438 1947

unit Example 13 Example 14 Example 15 Example 16 density g/ ^cm3 0.939 0.924 0.914 0.951 Flexural modulus MPa 1830 1430 1470 1830

unit Example 17 Example 18 density g/ ^cm3 0.934 0.925 Flexural modulus MPa 1713 1599

unit Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 density g/ ^cm3 0.940 0.925 0.940 0.925 Flexural modulus MPa 1662 1574 1419 1328

unit Comparative example 5 Comparative example 6 Comparative example 7 Comparative example 8 density g/ ^cm3 0.939 0.925 0.914 0.912 Flexural modulus MPa 1554 1491 1911 1454

From the comparison of Example 1 and Comparative Example 8, only 4% of glass fiber is added in homopolypropylene, the flexural modulus of the material is increased by 27%, and the density is only increased by 3%.

From the comparison of Example 2 and Comparative Example 8, only 2% of glass fiber is added in the homopolypropylene, the flexural modulus of the material is increased by 16%, and the density is only increased by 1.4%.

From the comparison of Example 9 and Comparative Example 8, only 4% of glass fiber is added in the mixture of copolymerized polypropylene and homopolypropylene, the flexural modulus of the material is increased by 19%, and the density is only increased by 3%.

Through the comparison of Example 1, Example 2, Example 9 and Comparative Example 8, it can be seen that a small amount of long glass fiber has a great effect on improving the modulus of polypropylene.

From the comparison of embodiment 1 and comparative example 1, the long glass fiber and short glass fiber respectively increased by 4% in homopolypropylene, the flexural modulus of embodiment 1 material has improved by 11.3% than comparative example 1, and the density Same. It can be seen that the modulus improvement of long glass fiber is better than that of short glass fiber.

From the comparison of embodiment 2 and comparative example 2, the long glass fiber and short glass fiber of 2% are respectively increased in homopolypropylene, and the flexural modulus of embodiment 2 material has improved 7% than comparative example 2, and density Same. It can be seen that the modulus improvement of long glass fiber is better than that of short glass fiber.

From the comparison between Example 14 and Example 6, the copolymerized polypropylene also contains 2% long glass fibers, and Example 14 does not use processing aid masterbatch, and the flexural modulus of the material is only 2% different from that of Example 6. , while the density is the same.

From the comparison of embodiment 1 and embodiment 13, in the homopolypropylene containing 4% long glass fiber equally, embodiment 13 does not use processing aid masterbatch, and the flexural modulus of material and embodiment 1 only differ by 1 %, while the density is the same.

In comparative example 7, the grade 5029 polypropylene used belongs to high crystallinity polypropylene with nucleating agent added. From the comparison of examples 1, 4 and comparative example 7, it can also be obtained by adding a small amount of long glass fiber. Same flexural modulus as crystalline polypropylene.

The present invention has been described by means of embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, the features and examples may be modified to adapt a particular situation and material to the teachings of the invention without departing from the spirit and scope of the invention. Therefore, the present invention is not limited by the specific embodiments disclosed here, and all embodiments falling within the scope of the claims of the present application belong to the protection scope of the present invention.

Claims (9)

1. A high-modulus low-density polypropylene, characterized in that: it is made from the following components proportioning by weight: Polypropylene 81~100 parts Long glass fiber reinforced polypropylene 0.5~15 parts. 2. The high-modulus and low-density polypropylene according to claim 1, characterized in that: the polypropylene is homopolypropylene or copolymerized polypropylene or a mixture of homopolypropylene and copolymerized polypropylene in any proportion. 3. The high-modulus low-density polypropylene according to claim 1, characterized in that: the total glass fiber content in the high-modulus low-density polypropylene is 0.2% to 6% of the total amount of the system. 4. The high-modulus low-density polypropylene according to claim 1, characterized in that: it also includes a processing aid, and the processing aid is one of a lubricant, an antioxidant, a light stabilizer, and a colorant or more. 5. The high modulus low density polypropylene according to claim 4, characterized in that: the lubricant is one of stearate, polyolefin wax, ethylene bis stearamide, pentaerythritol stearate one or more species. 6. The high-modulus low-density polypropylene according to claim 4, wherein the antioxidant is one of phenolic antioxidants, phosphite antioxidants, and thioester antioxidants one or more species. 7. The high-modulus low-density polypropylene according to claim 4, characterized in that: the light stabilizer is hindered amine light stabilizer, triazine light stabilizer, benzotriazole light stabilizer one or more. 8. The high modulus low density polypropylene according to claim 4, characterized in that: the colorant is one or more of inorganic pigments and organic pigments. 9. The preparation method of the high-modulus low-density polypropylene as claimed in the above-mentioned claim, is characterized in that: comprises the steps: Adopt known technology to obtain long glass fiber reinforced polypropylene; Obtain processing aid masterbatch by using known technology: mix polypropylene, lubricant, antioxidant, light stabilizer, and colorant evenly through a plastic extrusion granulator to obtain processing aid masterbatch; (3) Mix polypropylene, long glass fiber reinforced polypropylene and processing aid masterbatch in a certain proportion to make high modulus low density polypropylene.