CN107880384B

CN107880384B - Reinforced and toughened polypropylene material and preparation method thereof

Info

Publication number: CN107880384B
Application number: CN201711084610.4A
Authority: CN
Inventors: 秦小梅; 李白千; 彭晓翊; 陈玉; 王军; 罗庆敏
Original assignee: Foshan Rifeng Enterprise Co Ltd; Rifeng Enterprise Group Co Ltd; Rifeng Technology Co Ltd
Current assignee: Foshan Rifeng Enterprise Co Ltd; Rifeng Enterprise Group Co Ltd; Rifeng Technology Co Ltd
Priority date: 2017-11-07
Filing date: 2017-11-07
Publication date: 2021-04-02
Anticipated expiration: 2037-11-07
Also published as: CN107880384A

Abstract

The invention discloses a reinforced and toughened polypropylene material and a preparation method thereof, wherein the volume ratio of the reinforced and toughened polypropylene material is 6:3: 1, mixing absolute ethyl alcohol, chloroform and water; sequentially dissolving 0.1-3g of silane coupling agent and 0.1-3g of beta nucleating agent in a solvent to form a treatment solution; immersing 10-50 parts by weight of chopped glass fibers into the treatment solution, stirring for 2 hours at 80 ℃, then distilling under reduced pressure to remove the solvent, and drying at 120 ℃; mixing 100 parts by weight of polypropylene, 0.01-0.1 part by weight of lubricant and 0.5-1 part by weight of antioxidant, adding the mixture from a main feeding port of a double-screw extruder, adding the chopped glass fiber treated by the treatment fluid from a side feeding port of the double-screw extruder, and carrying out melt blending, drafting, extruding, cooling and pelletizing to obtain the polypropylene fiber. The invention has the advantages that: the beta crystal content and the crystallinity are high, the strength and the toughness of the material can be greatly improved by combining with the glass fiber reinforcement, the compatibility is good, the dosage of a treating agent is small, the preparation is convenient, and the material cost is low.

Description

Reinforced and toughened polypropylene material and preparation method thereof

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a reinforced and toughened polypropylene material and a preparation method thereof.

Background

The polypropylene pipe has the advantages of light weight, no toxicity, heat resistance, corrosion resistance, long service life, convenient installation, reliable connection, recyclability and the like, is used as a novel green building energy-saving material, and is widely applied to building water supply systems, heating systems, gas transmission systems, chemical fluid conveying systems, water treatment systems, agricultural irrigation systems and the like. With the rapid development of economy in China, the consumption of polypropylene pipes is greatly increased, the market share is rapidly improved, the polypropylene pipes are the first-pushed varieties of three novel plastic pipes which are mainly popularized by the ministry of construction in China, and the development trend is rapid in recent years.

However, at low temperature, the glass transition temperature of polypropylene is about 0 ℃, certain low-temperature brittleness exists below 5 ℃, and the pipe is easily damaged by external force at low temperature, so that inconvenience is brought to construction and transportation in winter in northern cold regions; at higher temperature, the strength of the polypropylene pipe is reduced, the pressure bearing capacity is reduced, and the application range of the polypropylene pipe is limited.

The technical solutions disclosed in most chinese patent documents CN201610608273, CN201410829021, CN201410520388, etc. are: the strength and toughness of polypropylene are improved by melting, compounding and modifying inorganic rigid particles such as glass fiber, talcum powder, mica and the like, various toughening agents, compatilizers, nucleating agents and other processing aids. The methods have the defects of complex components, more addition amount and high cost. In addition, the nucleating agent is not easily dispersed uniformly in the polypropylene matrix because of its small amount.

Disclosure of Invention

The invention aims to combine the reinforcing effect of glass fibers on a polypropylene material with the nucleating effect of a beta nucleating agent on polypropylene, and provide a reinforced and toughened polypropylene material which has high strength and good toughness, does not need to add a compatilizer and a toughening agent, and has uniformly dispersed nucleating agent.

The invention also aims to provide a preparation method of the reinforced and toughened polypropylene material, which is convenient to prepare and low in material cost.

The technical solution of the invention is as follows: a reinforced and toughened polypropylene material comprises the following raw material components: 100 parts of polypropylene, 10-50 parts of chopped glass fiber treated by the treatment fluid, 0.01-0.1 part of lubricant and 0.5-1 part of antioxidant, wherein the polypropylene is copolymerized polypropylene with the melt flow rate of 0.1-3g/min, and the treatment fluid comprises the following raw material components: 10-50ml of solvent, 0.1-3g of silane coupling agent and 0.1-2g of beta nucleating agent; the solvent is prepared from the following components in a volume ratio of 6:3: 1, mixing absolute ethyl alcohol, chloroform and water; the lubricant is prepared from the following components in parts by weight of 1: 2-3, the external lubricant is selected from one or more of fatty acid amide, stearic acid and salts thereof, and the internal lubricant is selected from one or more of hydrocarbon, organosilicon or micromolecular polymer lubricant; the antioxidant is selected from one or more of antioxidant 1076, antioxidant 1330, antioxidant DSTDP, antioxidant DLTDP 1010 and antioxidant 168.

Polypropylene is used for extrusion into pipes, so the melt flow rate of the polypropylene cannot be too high, which otherwise affects the mechanical properties and service life of the pipes, and if the melt flow rate is too high, the polypropylene cannot be extruded into pipes. After the lubricant is added, the uniform dispersion of the glass fiber in the matrix can be promoted, the modification effect is ensured, the processing performance of the polypropylene is optimized, and the product has smooth surface, good glossiness and no floating fiber. The antioxidant is added to prevent the polypropylene molecular chain from oxidative degradation, ensure the modification effect and greatly improve the heat resistance and the aging resistance of the polypropylene material. A large amount of hydroxyl groups are generated on the surface of the glass fiber soaked by the treatment solution, and a part of the hydroxyl groups react with silane, so that the compatibility of the glass fiber and a polypropylene matrix can be improved, the glass fiber is uniformly dispersed, and the material strength is improved; and a part of the nucleating agent can adsorb the beta nucleating agent, and finally the nucleating agent with low content is uniformly dispersed, so that the heterogeneous nucleation effect is better realized, the polypropylene forms beta crystals more and more quickly, and the toughness of the material is increased. The enhancement effect of the glass fiber on the polypropylene material and the nucleation effect of the beta nucleating agent on the polypropylene material are combined and cooperated, so that the strength and the toughness of the polypropylene material can be greatly improved, the processing is easy, and the phenomenon of fiber floating is avoided. All raw materials are easy to obtain, the addition amount of the treating agent is small, no additional compatilizer is needed, and the material cost is low. The pipe produced by using the material of the invention has greatly improved static pressure resistance and low temperature impact resistance.

The chopped glass fiber is alkali-free glass fiber with the diameter of 6-15 mu m and the length of 3-10 mm. The polypropylene composite has good compatibility with polypropylene materials, is assisted by a lubricant to help uniform dispersion, and can greatly improve the strength of the polypropylene materials.

The antioxidant is prepared from the following components in parts by weight of 2-3: 1: 1 antioxidant 1330, antioxidant 1076 and antioxidant DSTDP. The modification effect can be further ensured, and the heat resistance and the aging resistance of the polypropylene material are improved.

The silane coupling agent is selected from one or more of methoxysilane or ethoxysilane.

The pH value of the treatment liquid is 3.5-5.5.

The other technical solution of the invention is as follows: a preparation method of a reinforced and toughened polypropylene material comprises the following steps: preparing a mixed solvent: mixing the components in a volume ratio of 6:3: 1, mixing absolute ethyl alcohol, chloroform and water; preparing a treatment solution: sequentially dissolving 0.1-3g of silane coupling agent and 0.1-3g of beta nucleating agent in a solvent to form a treatment solution; processing glass fibers: immersing 10-50 parts by weight of chopped glass fibers into the treatment solution, stirring for 2 hours at 80 ℃, then distilling under reduced pressure to remove the solvent, and drying at 120 ℃; mixing 100 parts by weight of polypropylene, 0.01-0.1 part by weight of lubricant and 0.5-1 part by weight of antioxidant, adding the mixture from a main feeding port of a double-screw extruder, adding the chopped glass fiber treated by the treatment fluid from a side feeding port of the double-screw extruder, and carrying out melt blending, drafting, extrusion, cooling and grain cutting to obtain the polypropylene fiber.

The step II is also provided with a step of adjusting the pH value of the treatment solution to 3.5-5.5. Is beneficial to increasing the hydroxyl on the surface of the glass fiber, and further improves the compatibility of the glass fiber and the material and the uniform dispersibility of the nucleating agent.

The processing temperature in the step (IV) is 170-220 ℃.

The invention has the advantages that:

(1) the beta nucleating agent is used for modifying polypropylene, the crystallinity of the polypropylene is improved, the polypropylene is in a beta crystal form, and the strength and toughness of the material can be greatly improved by combining glass fiber reinforcement.

(2) The glass fiber and the beta nucleating agent can be promoted to be uniformly dispersed in the polypropylene matrix under the action of the treatment liquid, and the good synergistic modification effect of the glass fiber and the beta nucleating agent can be exerted.

(3) The raw materials used in the invention are easy to obtain, the addition of treating agents and the like is little, the preparation is convenient, no additional compatilizer or toughening agent is needed, and the material cost is low.

Detailed Description

The raw materials used in the embodiment of the invention are as follows:

the polypropylene resin has abundant raw materials and more marks, and can be selected, the PP-R material of the Korean Xiaoxing, the mark R200P, is used in the embodiment;

the alkali-free chopped glass fiber is T438 of Mount Taishan glass fiber company, the diameter of the glass fiber is 13 mu m, and the length of the glass fiber is 4.5 mm;

the silane coupling agent is vinyl triethoxysilane, morning light chemical engineering, CG-V151;

the beta nucleating agent is NA-287, Basff;

the external lubricant is ethylene bis stearamide EBS, King of Japan;

the internal lubricant is modified polyester resin HY390, Shanghai Huiyuan New Material Co., Ltd

The antioxidant is as follows: antioxidants 1076, 1330, agents DSTDP, 1010, basf;

chloroform and absolute ethyl alcohol are commercially available, and water is purified water.

Example 1:

(1) preparing a mixed solvent: adding absolute ethyl alcohol, chloroform and water according to the weight ratio of 6:3: 1 to prepare a mixed solvent;

(2) preparing a treatment solution: dissolving 5g of nucleating agent NA-287 and 75g of vinyl triethoxysilane CG-V151 in 1500ml of solvent in sequence in a mixed solvent, and adjusting the pH value of a treatment solution to 3.5-5.5;

(3) glass fiber treatment: immersing 1.5kg of chopped glass fibers into the treatment solution, mechanically stirring for 2h at 80 ℃, then distilling under reduced pressure to remove the solvent, and drying at 120 ℃;

(4) 5Kg of polypropylene, 50g of antioxidant (1330: 1076: DSTDP ═ 2: 1: 1) and 5g of lubricant (EBS: HY390 ═ 1: 2) are stirred at high speed, fully mixed and added into a double-screw extruder from a main feeding port for melting, the treated chopped glass fibers are added into the double-screw extruder from a side feeding port for melting and blending, drafting, extruding, cooling and granulating to obtain the reinforced polypropylene material. The processing temperature is controlled at 220 ℃ of 170 DEG C

Comparative example 1

5Kg of polypropylene, 50g of antioxidant (1330: 1076: DSTDP ═ 2: 1: 1) and 5g of lubricant (EBS: HY390 ═ 1: 2) are stirred at high speed, fully mixed and added into a double-screw extruder from a main feeding port for melting, and the mixture is melted, blended, stretched, extruded, cooled and cut into granules. The processing temperature is controlled at 220 ℃ of 170 DEG C

Comparative example 2

(2) preparing a treatment solution: dissolving 75g of vinyl triethoxysilane CG-V151 in 1500ml of solvent, and adjusting the pH value of the treatment solution to 3.5-5.5;

(4) 5Kg of polypropylene, 50g of antioxidant (1330: 1076: DSTDP ═ 2: 1: 1) and 5g of lubricant (EBS: HY390 ═ 1: 2) are stirred at high speed, fully mixed and added into a double-screw extruder from a main feeding port for melting, the treated chopped glass fibers are added into the double-screw extruder from a side feeding port for melting and blending, drafting, extruding, cooling and granulating. The processing temperature is controlled at 220 ℃ of 170 DEG C

Comparative example 3

(2) preparing a treatment solution: taking 1500ml of solvent, sequentially dissolving 125g of nucleating agent NA-287 and 75g of vinyl triethoxysilane CG-V151 in the mixed solvent, and adjusting the pH value of the treatment solution to 3.5-5.5;

(4) 5Kg of polypropylene, 50g of antioxidant (1330: 1076: DSTDP ═ 2: 1: 1) and 5g of lubricant (EBS: HY390 ═ 1: 2) are stirred at high speed, fully mixed and added into a double-screw extruder from a main feeding port for melting, the treated chopped glass fibers are added into the double-screw extruder from a side feeding port for melting and blending, drafting, extruding, cooling and granulating to obtain the reinforced polypropylene material. The processing temperature is controlled at 170-220 ℃.

The preparation of examples 2 to 5 was carried out in accordance with example 1, the composition of the various examples and comparative examples being as shown in Table 1 below:

TABLE 1

The test results are shown in table 2 below:

TABLE 2

Comparing examples 1-5 with comparative examples 1-3, it can be seen that the addition of glass fiber and beta nucleating agent can act as a synergistic enhancement and toughening effect. With the increase of the content of the beta nucleating agent, the material starts to crystallize early, the crystal grains are refined, the content of the beta crystal is increased, and the tensile strength and the impact strength of the material are improved. When the beta nucleating agent is increased to a certain amount, the material performance is gradually stabilized; when the beta nucleating agent is excessive, the nucleating effect exerted is limited, and the excessive nucleating agent may become a defect in the material, resulting in a decrease in performance.

The preparation methods of examples 6 to 9 and comparative examples 4 to 5 were identical to example 1, and the component ratios of the respective examples and comparative examples are shown in table 3 below:

TABLE 3

The test results are shown in table 4 below:

TABLE 4

The addition of vinyltriethoxysilane is not required, so that the interface bonding force between the glass fiber and the polypropylene matrix is poor, and even if the beta crystal content of the material is higher due to the beta nucleating agent, the poor compatibility of the glass fiber and the polypropylene becomes a physical defect in the material, so that the tensile strength and the impact of the material are reduced. Along with the increase of the content of the vinyltriethoxysilane, the surface treatment of the glass fiber is gradually improved, the compatibility of the glass fiber and a polypropylene matrix becomes good, the interface binding force is enhanced, and the performance of the material is greatly improved. When the content of the vinyltriethoxysilane exceeds a certain content, the surface treatment of the glass fiber reaches a saturated state, and the performance change is not large.

The preparation methods of examples 10 to 11 and comparative examples 6 to 7 were identical to example 1, and the component ratios of the respective examples and comparative examples are shown in the following table 5:

TABLE 5

The test results are shown in table 6 below:

TABLE 6

In combination with example 3, it can be seen that the addition of the lubricant can prevent the glass fibers from being exposed, improve the processing fluidity of the system, and promote the uniform dispersion of the glass fibers in the polypropylene system. As the amount of lubricant added increases, the performance of the material improves, but the overall difference is not great. However, if the amount of the additive is too large, the material slips and the material properties are deteriorated.

Example 12 and comparative examples 8-9 were formulated as shown in table 7 below:

TABLE 7

The test results are shown in table 8 below:

TABLE 8

It can be seen from example 3 that the ratio of the inner and outer lubricants has an effect on the properties of the material. From the test results, the external lubricant: the proportion of the internal lubricant is 1: 2-3 is more preferable.

The preparation methods of examples 13 to 14 and comparative examples 10 to 11 were identical to example 1, and the component ratios of the respective examples and comparative examples are shown in the following table 9:

TABLE 9

The test results are shown in table 10 below:

watch 10

Combining with the embodiment 3, the addition of the antioxidant can prevent the polypropylene molecular chain from oxidative degradation and ensure the material performance. With the increase of the addition amount of the antioxidant, the oxidation induction period (OIT) of the system is prolonged, and the material performance is better. When the addition amount of the antioxidant exceeds a certain content, the performance is not changed greatly.

Examples 15-19 and comparative examples 12-13 the formulations are shown in table 11 below:

TABLE 11

The test results are shown in table 12 below:

TABLE 12

By combining the example 3, the antioxidant effect of the single component is not obvious, and the compound antioxidant with proper proportion can exert good synergistic effect, so that the aging resistance and other properties of the polypropylene material are better.

The examples 20-23 and comparative examples 14-15 were prepared in accordance with example 1, with the component ratios for each example and comparative example shown in table 13 below:

watch 13

The test results are shown in table 14 below:

TABLE 14

Test items	Tensile Strength (MPa)	Cantilever beam impact strength 0 deg.C (KJ/m)²)
			Example 20	28	10
Example 21	36	15
			Example 3	45	22
Example 22	42	22
			Example 23	34	23
Comparative example 14	17	13
			Comparative example 15	19	7

In combination with example 3, it can be seen that the addition of the glass fibers has a significant reinforcing effect, and the tensile strength of the material is greatly increased with the increase of the content of the glass fibers. After the treatment of the treatment liquid, the compatibility of the chopped glass fiber and polypropylene is good, the uniform dispersion of the beta nucleating agent in the matrix is promoted, and the impact performance of the material is obviously improved. When the glass fiber is too much, it may become a defect in the material due to more difficult dispersion, resulting in a decrease in the material properties.

Comparative examples 16, 17: the solvent ratio in example 3 was changed to absolute ethanol: chloroform: the water content is 6:3: 2 and 6:3:0, and the rest steps are unchanged;

comparative example 18: the procedure of example 3 was repeated except that "pH of the conditioning solution was adjusted to 3.5 to 5.5" in the step (2) was removed.

Comparative example 19: the glass fiber treatment temperature in example 1 was changed to 70 ℃ and the rest was not changed.

Comparative example 20: the glass fiber treatment temperature in example 1 was changed to 90 ℃ and the rest was not changed.

The test results are shown in table 15 below:

watch 15

Test items	Tensile Strength (MPa)	Cantilever beam impact strength 0 deg.C (KJ/m)²)
			Test method	GB/T 1040	GB/T 1843
Example 3	45	22
			Comparative example 16	37	18
Comparative example 17	22	9
			Comparative example 18	34	16
Comparative example 19	30	14
			Comparative example 20	46	21

As can be seen from the example 3 and the comparative examples 16 to 20, the content of water in the mixed solvent used in the invention should not be too much, too much vinyl silane is easy to be condensed in the hydrolysis process, the treatment effect on the glass fiber is reduced, too little or no vinyl silane is not sufficient to be hydrolyzed, and the treatment effect on the glass fiber is not ideal, so that the compatibility between the glass fiber and polypropylene is poor, and the material performance is reduced.

As can be seen from the comparison between example 3 and comparative example 18, the pH value of the treatment solution is adjusted to be in a dilute acid environment, so that the hydrolysis of vinyl silane can be promoted, and the glass fiber treatment effect can be improved.

As is clear from the comparison between example 3 and comparative examples 19 and 20, the temperature is too low, the surface treatment of the vinyl silane to the glass fiber is not sufficient within the reaction time of 2 hours, and the effect is almost the same as that of example 1 at higher treatment temperature, so the temperature used in the examples is better from the viewpoint of energy saving.

The reinforced and toughened polypropylene material prepared by the invention is used for producing polypropylene pipes of S3.2Dn75 10.3, and the hydrostatic strength and the drop hammer impact strength of the pipes are tested under different conditions, and the results are shown in the following tables 16 and 17, which show that the pressure resistance and the low-temperature impact toughness of the pipes produced by the polypropylene material are obviously enhanced. TABLE 16

TABLE 17

Claims

1. The reinforced and toughened polypropylene material is characterized by comprising the following raw material components: 100 parts of polypropylene, 10-50 parts of chopped glass fiber treated by treatment fluid, 0.01-0.1 part of lubricant and 0.5-1 part of antioxidant, wherein the polypropylene is copolymerized polypropylene with melt flow rate of 0.1-3g/min, and the operation of treating the glass fiber by the treatment fluid comprises the following steps: immersing 10-50 parts by weight of chopped glass fibers into a treatment solution, stirring for 2 hours at 80 ℃, distilling under reduced pressure to remove a solvent, and drying at 120 ℃, wherein the treatment solution of the glass fibers comprises the following raw materials: 1500ml of solvent, 75g of vinyltriethoxysilane, 5g of NA-287 beta nucleating agent, and the pH value of the treatment solution is adjusted to 3.5-5.5; the solvent is prepared from the following components in a volume ratio of 6:3: 1, mixing absolute ethyl alcohol, chloroform and water; the dosage of the glass fiber is 1g compared with 1mL of the solvent glass fiber; the lubricant is prepared from the following components in parts by weight of 1: 2-3, the external lubricant is selected from one or more of fatty acid amide, stearic acid and salts thereof, and the internal lubricant is selected from one or more of hydrocarbon, organosilicon or micromolecular polymer lubricant; the antioxidant is selected from one or more of antioxidant 1076, antioxidant 1330, antioxidant DSTDP, antioxidant 1010 or antioxidant 168, and the method for treating the glass fiber by using the treatment solution comprises the following steps: and immersing all parts by weight of chopped glass fibers into the treatment solution, stirring, distilling under reduced pressure to remove the solvent, and drying.

2. The reinforced and toughened polypropylene material as claimed in claim 1, wherein said chopped glass fiber is an alkali-free glass fiber having a diameter of 6-15 μm and a length of 3-10 mm.

3. The reinforced and toughened polypropylene material as claimed in claim 1, wherein said antioxidant is selected from the group consisting of antioxidant 1330, antioxidant 1076 and antioxidant DSTDP, wherein the ratio of antioxidant 1330, antioxidant 1076 and antioxidant DSTDP is 2-3: 1: 1.