阅读说明：本技术 一种改进的高强度耐刮擦聚丙烯材料及制备方法 (Improved high-strength scratch-resistant polypropylene material and preparation method thereof ) 是由 *** 于 2019-12-04 设计创作，主要内容包括：本发明属于聚丙烯材料技术领域,公开了一种改进的高强度耐刮擦聚丙烯材料及制备方法,改进的高强度耐刮擦聚丙烯材料由聚丙烯、聚对苯二甲酸乙二醇酯、茂金属聚乙烯、碳酸钙、芥酸酰胺、改性玄武岩纤维、增韧剂、相容剂、纳米二氧化硅以及加工助剂组成。本发明可以提高聚丙烯材料的强度；通过提供的碳酸钙的制备方法可以制备高活性的碳酸钙,从而提升聚丙烯材料制备效率。本发明对玄武岩纤维进行表面改性处理,增强玄武岩纤维与聚丙烯基体的界面结合力；将LFT纤维浸润制备工艺运用到玄武岩纤维改性聚丙烯材料中,使得纤维长度保留10-15mm,即纤维在聚烯烃基体中的保留长度较长,从而提高了制件的机械强度。(The invention belongs to the technical field of polypropylene materials, and discloses an improved high-strength scratch-resistant polypropylene material and a preparation method thereof. The invention can improve the strength of the polypropylene material; the preparation method of the calcium carbonate can prepare the high-activity calcium carbonate, thereby improving the preparation efficiency of the polypropylene material. The method carries out surface modification treatment on the basalt fiber, and enhances the interface bonding force of the basalt fiber and a polypropylene matrix; the LFT fiber infiltration preparation process is applied to the basalt fiber modified polypropylene material, so that the fiber length is reserved for 10-15mm, namely the reserved length of the fiber in the polyolefin matrix is longer, and the mechanical strength of the finished piece is improved.)

1. The preparation method of the improved high-strength scratch-resistant polypropylene material is characterized by comprising the following steps:

step one, mixing and stirring a compatilizer, a flexibilizer, a processing aid and calcium carbonate at the high temperature of 120-2000-; the preparation of the calcium carbonate specifically comprises the following steps:

1) weighing 10 parts of calcium carbonate, 15 parts of oleic acid, 0.5 part of sodium dodecyl benzene sulfonate, 3 parts of sodium bicarbonate, 5 parts of styrene, 25 parts of epoxy resin, 8 parts of triethyl citrate, 15 parts of plant ash, 9 parts of graphene, 5 parts of glass fiber, 6 parts of stearic acid, 5 parts of a silane coupling agent and 9 parts of an activating agent;

2) crushing calcium carbonate and sodium bicarbonate, uniformly mixing with plant ash, putting into a high-speed mixer, stirring and heating, stopping heating and adding a silane coupling agent when the temperature in the mixer is 80 ℃, continuing stirring for 30min, heating to 110 ℃, adding triethyl citrate, sodium dodecyl benzene sulfonate and glass fiber, stirring for 10min, and cooling to room temperature to obtain modified calcium carbonate;

3) heating epoxy resin to 75 ℃, adding graphene, styrene, oleic acid and stearic acid, preserving heat for 1h, adding modified calcium carbonate, cooling to 60 ℃, adding an activating agent, and preserving heat for 1h to obtain calcium carbonate;

step two, adding polypropylene, metallocene polyethylene, erucamide and nano silicon dioxide into a high-speed mixer, mixing and stirring for 5-10min to obtain a mixed material B; the preparation of the metallocene polyethylene specifically comprises the following steps:

(1) adding 0.5 part of polyethylene glycol, 0.2 part of calcium stearate, 0.3 part of zinc stearate, 0.04 part of antioxidant and 0.2 part of antioxidant into 100 parts of mLLDPE resin;

(2) mixing in a high-speed stirrer at a stirring speed of 1500 rpm for 13min at a stirring temperature of 38 ℃; adding the uniformly mixed materials into a double-screw extruder for melting, plasticizing, extruding and granulating;

the length-diameter ratio of the double screws is 35, 8 sections of shear blocks in the adopted screw combination and 3 sections of reverse shear blocks in the 8 sections are adopted; the processing temperature is 180 ℃, and the gradient distribution is realized; vacuumizing in the granulation process, wherein the granulation vacuumizing reaches the vacuum degree of-0.3 MPa;

step three, mixing the primary mixed material A obtained in the step one and the mixed material B obtained in the step two, adding the mixture into a double-screw extruder, carrying out melt extrusion in the double-screw extruder, then gradually cooling, and carrying out air cooling and grain cutting to obtain the improved high-strength scratch-resistant polypropylene material;

the cooling temperature is 220 ℃, 200 ℃, 160 ℃ and 110 ℃ in sequence.

2. The method for preparing the improved high-strength scratch-resistant polypropylene material according to claim 1, wherein in the first step, the modified basalt fiber is prepared by the following steps:

soaking the basalt fiber in an acid solution, taking out and drying to obtain the primarily surface-modified basalt fiber; and then coating hybrid slurry prepared from epoxy resin, graphene oxide and a silane coupling agent on the basalt fiber with the primarily modified surface, and airing to prepare the modified basalt fiber.

3. The method for preparing an improved high-strength scratch-resistant polypropylene material according to claim 2, wherein the acid solution is an aqueous acetic acid solution; the epoxy resin is glycidyl ether epoxy resin; the silane coupling agent is one of KH550, KH560 and KH 570.

4. The improved high-strength scratch-resistant polypropylene material as claimed in claim 3, wherein the mass fraction of the acetic acid aqueous solution is 2-10%.

5. The improved high-strength, scratch-resistant polypropylene material according to claim 3, wherein the basalt fiber is soaked for 4 to 8 hours.

6. The improved high-strength scratch-resistant polypropylene material as claimed in claim 3, wherein the mass ratio of the components in the hybrid slurry is epoxy resin: and (3) graphene oxide: silane coupling agent = (98-88): (1-6).

7. The improved high-strength scratch-resistant polypropylene material prepared by the preparation method of the improved high-strength scratch-resistant polypropylene material as claimed in any one of claims 1 to 6 is characterized by comprising, by mass, 40% to 70% of polypropylene, 12% to 20% of polyethylene terephthalate, 10% to 15% of metallocene polyethylene, 8% to 13% of calcium carbonate, 5% to 10% of erucamide, 9% to 17% of modified basalt fiber, 5% to 10% of a toughening agent, 3% to 6% of a compatilizer, 3% to 5% of nano silica and 0.2% to 0.5% of a processing aid.

8. The improved high-strength scratch-resistant polypropylene material according to claim 7, wherein the compatilizer is at least one of PP grafted maleic anhydride and POE grafted maleic anhydride; the toughening agent is at least one of POE and PE.

9. The improved high strength, scratch resistant polypropylene material of claim 7 wherein the processing aid is a mixing aid of a lubricant and an antioxidant in a weight ratio of 1: 2;

the lubricant is calcium stearate; the antioxidant is a mixture of hindered phenol antioxidant and phosphite ester antioxidant and/or thioester antioxidant, and the ratio of the weight of the hindered phenol antioxidant to the total weight of the phosphite ester antioxidant and the thioester antioxidant is 1: 2.5-8.

10. A part in the fields of machinery, automobiles, electronic and electric appliances, buildings, textiles, agriculture, forestry, fishery and food industry, which is prepared by using the improved high-strength scratch-resistant polypropylene material as claimed in any one of claims 7 to 9.

Technical Field

The invention belongs to the technical field of polypropylene materials, and particularly relates to an improved high-strength scratch-resistant polypropylene material and a preparation method thereof.

Background

Polypropylene, PP for short, is a colorless, odorless, nontoxic and semitransparent solid substance. Polypropylene (PP) is a thermoplastic synthetic resin with excellent performance, and is colorless translucent thermoplastic light general-purpose plastic. The polypropylene has chemical resistance, heat resistance, electrical insulation, high-strength mechanical property, good high-wear-resistance processing property and the like, so that the polypropylene can be rapidly and widely developed and applied in a plurality of fields such as machinery, automobiles, electronic and electric appliances, buildings, textiles, packaging, agriculture, forestry, fishery, food industry and the like since the coming out. In recent years, with the rapid development of the industries such as packaging, electronics, automobiles and the like in China, the development of the industries in China is greatly promoted. And because of its plasticity, polypropylene materials are gradually replacing wooden products, and the mechanical functions of metals have been gradually replaced by high strength toughness and high wear resistance. In addition, the polypropylene has good grafting and compounding functions, and has huge application space in the aspects of concrete, textile, packaging and agriculture, forestry and fishery; however, in the existing polypropylene material preparation process, the adopted metallocene polyethylene has poor performance and low calcium carbonate activity; resulting in low strength and low preparation efficiency of the prepared polypropylene.

The basalt fiber is a green and environment-friendly mineral fiber, because the basalt fiber has no harm to human bodies and can be degraded in soil. Compared with the traditional glass fiber and carbon fiber, the acquisition of mineral sources of basalt fiber has received more and more extensive attention, and the application field is gradually expanded. The basalt fiber has high elastic modulus, good heat resistance, high compressive strength and shear strength, excellent acoustic resistance and vibration isolation characteristics, and is a new base material and high-technology fiber meeting the requirements of national economy basic industry development. At present, most of common methods for reinforcing polypropylene by basalt fibers are to directly add a reinforcing filler and obtain a reinforced polypropylene composite material by side feeding and extruding through an extruder, but the basalt fiber reinforced polypropylene composite material obtained by the method has short fiber retention length of only about 0.2mm, so that the comprehensive properties of the composite material, such as stretching, bending, impact and the like, are poor.

In summary, the problems of the prior art are as follows: (1) in the existing preparation process of polypropylene materials, metallocene polyethylene adopted has poor performance and low calcium carbonate activity; resulting in low strength and low preparation efficiency of the prepared polypropylene.

(2) The existing basalt fiber reinforced polypropylene method is mostly to directly add a reinforcing filler and obtain a reinforced polypropylene composite material by side feeding and extruding through an extruder, but the basalt fiber reinforced polypropylene composite material obtained by the method has short fiber retention length of only about 0.2mm, so that the comprehensive properties of the basalt fiber reinforced polypropylene composite material, such as stretching, bending, impact and the like, are poor.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an improved high-strength scratch-resistant polypropylene material and a preparation method thereof.

The improved high-strength scratch-resistant polypropylene material is prepared from, by mass, 40% -70% of polypropylene, 12% -20% of polyethylene terephthalate, 10% -15% of metallocene polyethylene, 8% -13% of calcium carbonate, 5% -10% of erucamide, 9% -17% of modified basalt fibers, 5% -10% of a toughening agent, 3% -6% of a compatilizer, 3% -5% of nano-silica and 0.2% -0.5% of a processing aid.

Further, the compatilizer is at least one of PP grafted maleic anhydride and POE grafted maleic anhydride; the toughening agent is at least one of POE and PE; the processing aid is a mixed aid of a lubricant and an antioxidant, and the weight ratio of the processing aid to the antioxidant is 1: 2.

further, the lubricant is calcium stearate; the antioxidant is a mixture of hindered phenol antioxidant and phosphite ester antioxidant and/or thioester antioxidant, and the ratio of the weight of the hindered phenol antioxidant to the total weight of the phosphite ester antioxidant and the thioester antioxidant is 1: 2.5-8.

Another object of the present invention is to provide a preparation method of the improved high-strength scratch-resistant polypropylene material, which comprises the following steps:

step one, mixing and stirring the compatilizer, the flexibilizer, the processing aid and the calcium carbonate for 10-20min at the high temperature of 120-150 ℃, then adding the nano silicon dioxide, the polyethylene glycol terephthalate and the modified basalt fiber, and uniformly stirring and mixing to obtain a primary mixed material A.

And step two, adding the polypropylene, the metallocene polyethylene, the erucamide and the nano silicon dioxide into a high-speed mixer, and mixing and stirring for 5-10min to obtain a mixed material B.

And step three, mixing the primary mixed material A obtained in the step one and the mixed material B obtained in the step two, adding the mixture into a double-screw extruder, carrying out melt extrusion in the double-screw extruder, then gradually cooling, and carrying out air cooling and grain cutting to obtain the improved high-strength scratch-resistant polypropylene material.

Further, in the first step, the rotation speed of the high-speed mixer is 1800-.

Further, in the first step, the preparation method of the metallocene polyethylene comprises the following steps:

(1) 100 portions of mLLDPE resin are added with 0.5 portion of polyethylene glycol, 0.2 portion of calcium stearate, 0.3 portion of zinc stearate, 0.04 portion of antioxidant and 0.2 portion of antioxidant,

(2) mixing in a high-speed stirrer at a stirring speed of 1500 rpm for 13min at a stirring temperature of 38 ℃; and adding the uniformly mixed materials into a double-screw extruder for melting, plasticizing, extruding and granulating.

Further, the length-diameter ratio of the screw is 35, and 8 sections of shear blocks in the adopted screw combination are 3 sections of reverse shear blocks; the processing temperature is 180 ℃, and the gradient distribution is realized; vacuumizing in the granulation process, wherein the vacuum degree of granulation vacuumizing is-0.3 MPa.

Further, in the first step, the preparation method of the calcium carbonate comprises the following steps:

1) weighing 10 parts of calcium carbonate, 15 parts of oleic acid, 0.5 part of sodium dodecyl benzene sulfonate, 3 parts of sodium bicarbonate, 5 parts of styrene, 25 parts of epoxy resin, 8 parts of triethyl citrate, 15 parts of plant ash, 9 parts of graphene, 5 parts of glass fiber, 6 parts of stearic acid, 5 parts of a silane coupling agent and 9 parts of an activating agent;

2) crushing calcium carbonate and sodium bicarbonate, uniformly mixing with plant ash, putting into a high-speed mixer, stirring and heating, stopping heating and adding a silane coupling agent when the temperature in the mixer is 80 ℃, continuing stirring for 30min, heating to 110 ℃, adding triethyl citrate, sodium dodecyl benzene sulfonate and glass fiber, stirring for 10min, and cooling to room temperature to obtain modified calcium carbonate;

3) heating the epoxy resin to 75 ℃, adding graphene, styrene, oleic acid and stearic acid, preserving heat for 1h, adding modified calcium carbonate, cooling to 60 ℃, adding an activating agent, and preserving heat for 1h to obtain the activated calcium carbonate.

Further, in the first step, the preparation method of the modified basalt fiber comprises the following steps:

soaking the basalt fiber in an acid solution, taking out and drying to obtain the primarily surface-modified basalt fiber; and then coating hybrid slurry prepared from epoxy resin, graphene oxide and a silane coupling agent on the basalt fiber with the primarily modified surface, and airing to prepare the modified basalt fiber.

Further, the acid solution is an acetic acid aqueous solution; the epoxy resin is glycidyl ether epoxy resin; the silane coupling agent is one of KH550, KH560 and KH 570; wherein the mass fraction of the acetic acid aqueous solution is 2-10%, and the soaking time of the basalt fiber in the acetic acid aqueous solution is 4-8 hours; the mass ratio of each component in the hybrid slurry is that the epoxy resin: and (3) graphene oxide: silane coupling agent = (98-88): (1-6).

Further, in the third step, the cooling temperature is 220 ℃, 200 ℃, 160 ℃ and 110 ℃ in sequence.

Another object of the invention is to provide a part prepared by utilizing the improved high-strength scratch-resistant polypropylene material in the fields of machinery, automobiles, electronic and electric appliances, construction, textile, agriculture, forestry, fishery and food industry.

The invention has the advantages and positive effects that: the improved preparation method of the high-strength scratch-resistant polypropylene material can be used for preparing the high-strength scratch-resistant polypropylene material; the metallocene polyethylene with high strength can be prepared by the preparation method of the metallocene polyethylene, so that the strength of the polypropylene material is improved; meanwhile, the preparation method of the calcium carbonate can be used for preparing the high-activity calcium carbonate, so that the preparation efficiency of the polypropylene material is improved.

The method carries out surface modification treatment on the basalt fiber, and enhances the interface bonding force of the basalt fiber and a polypropylene matrix; firstly, the surface of basalt fiber is modified by acetic acid aqueous solution, the microstructure is changed from smooth to rough, the organic matrix epoxy resin in the hybrid slurry is favorably permeated on the surface of the fiber, and in addition, the graphene oxide in the hybrid slurry can improve the strength of the material; and the silane coupling agent is utilized to improve the compatibility between the fiber and the polypropylene resin matrix, thereby further improving the strength of the material. According to the invention, the LFT fiber infiltration preparation process is applied to the basalt fiber modified polypropylene material, so that the fiber length is reserved for 10-15mm, namely the reserved length of the fiber in the polyolefin matrix is longer, and the mechanical strength of the finished piece is improved.

Drawings

FIG. 1 is a flow chart of a preparation method of an improved high-strength scratch-resistant polypropylene material provided by the implementation of the invention.

FIG. 2 is an infrared spectrum test chart of the improved high-strength scratch-resistant polypropylene material provided by the implementation of the invention.

In the figure: a. (ii) unmodified; b after modification.

FIG. 3 is an SEM image of an improved high strength scratch and mar resistant polypropylene material provided by the practice of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The present invention will be described in detail below with reference to the accompanying drawings.

The improved high-strength scratch-resistant polypropylene material provided by the embodiment of the invention comprises, by mass, 40% -70% of polypropylene, 12% -20% of polyethylene terephthalate, 10% -15% of metallocene polyethylene, 8% -13% of calcium carbonate, 5% -10% of erucamide, 9% -17% of modified basalt fibers, 5% -10% of a toughening agent, 3% -6% of a compatilizer, 3% -5% of nano-silica and 0.2% -0.5% of a processing aid.

The compatilizer provided by the invention is at least one of PP grafted maleic anhydride and POE grafted maleic anhydride; the toughening agent is at least one of POE and PE; the processing aid is a mixed aid of a lubricant and an antioxidant, and the weight ratio of the processing aid to the antioxidant is 1: 2.

the lubricant provided by the invention is calcium stearate; the antioxidant is a mixture of hindered phenol antioxidant and phosphite ester antioxidant and/or thioester antioxidant, and the ratio of the weight of the hindered phenol antioxidant to the total weight of the phosphite ester antioxidant and the thioester antioxidant is 1: 2.5-8.

As shown in FIG. 1, the preparation method of the improved high-strength scratch-resistant polypropylene material provided by the embodiment of the invention comprises the following steps:

s101: mixing and stirring the compatilizer, the flexibilizer, the processing aid and the calcium carbonate for 10-20min at the high temperature of 120-150 ℃, then adding the nano silicon dioxide, the polyethylene terephthalate and the modified basalt fiber, and uniformly stirring and mixing to obtain a primary mixed material A.

S102: and adding the polypropylene, the metallocene polyethylene, the erucamide and the nano silicon dioxide into a high-speed mixer, and mixing and stirring for 5-10min to obtain a mixed material B.

S103: and (3) mixing the primary mixed material A obtained in the step (S101) and the mixed material B obtained in the step (S102), adding the mixture into a double-screw extruder, carrying out melt extrusion in the double-screw extruder, then gradually cooling, and carrying out air cooling and grain cutting to obtain the improved high-strength scratch-resistant polypropylene material.

In S101 provided by the invention, the rotating speed of the high-speed mixer is 1800-.

In S101 provided by the present invention, the preparation method of the metallocene polyethylene comprises:

(1) 100 portions of mLLDPE resin are added with 0.5 portion of polyethylene glycol, 0.2 portion of calcium stearate, 0.3 portion of zinc stearate, 0.04 portion of antioxidant and 0.2 portion of antioxidant,

(2) mixing in a high-speed stirrer at a stirring speed of 1500 rpm for 13min at a stirring temperature of 38 ℃; and adding the uniformly mixed materials into a double-screw extruder for melting, plasticizing, extruding and granulating.

The length-diameter ratio of the screw provided by the invention is 35, and 8 sections of shear blocks in the adopted screw combination are 3 sections of reverse shear blocks; the processing temperature is 180 ℃, and the gradient distribution is realized; vacuumizing in the granulation process, wherein the vacuum degree of granulation vacuumizing is-0.3 MPa.

In the S101 provided by the invention, the preparation method of the calcium carbonate is as follows:

1) weighing 10 parts of calcium carbonate, 15 parts of oleic acid, 0.5 part of sodium dodecyl benzene sulfonate, 3 parts of sodium bicarbonate, 5 parts of styrene, 25 parts of epoxy resin, 8 parts of triethyl citrate, 15 parts of plant ash, 9 parts of graphene, 5 parts of glass fiber, 6 parts of stearic acid, 5 parts of a silane coupling agent and 9 parts of an activating agent;

2) crushing calcium carbonate and sodium bicarbonate, uniformly mixing with plant ash, putting into a high-speed mixer, stirring and heating, stopping heating and adding a silane coupling agent when the temperature in the mixer is 80 ℃, continuing stirring for 30min, heating to 110 ℃, adding triethyl citrate, sodium dodecyl benzene sulfonate and glass fiber, stirring for 10min, and cooling to room temperature to obtain modified calcium carbonate;

3) heating the epoxy resin to 75 ℃, adding graphene, styrene, oleic acid and stearic acid, preserving heat for 1h, adding modified calcium carbonate, cooling to 60 ℃, adding an activating agent, and preserving heat for 1h to obtain the activated calcium carbonate.

In S101 provided by the invention, the preparation method of the modified basalt fiber comprises the following steps:

soaking the basalt fiber in an acid solution, taking out and drying to obtain the primarily surface-modified basalt fiber; and then coating hybrid slurry prepared from epoxy resin, graphene oxide and a silane coupling agent on the basalt fiber with the primarily modified surface, and airing to prepare the modified basalt fiber.

The acid solution provided by the invention is an acetic acid aqueous solution; the epoxy resin is glycidyl ether epoxy resin; the silane coupling agent is one of KH550, KH560 and KH 570; wherein the mass fraction of the acetic acid aqueous solution is 2-10%, and the soaking time of the basalt fiber in the acetic acid aqueous solution is 4-8 hours; the mass ratio of each component in the hybrid slurry is that the epoxy resin: and (3) graphene oxide: silane coupling agent = (98-88): (1-6).

In the step S103, the cooling temperature is 220 ℃, 200 ℃, 160 ℃ and 110 ℃ in sequence.

The invention is further described with reference to specific examples.