CN105647172B - A kind of wear-resisting long basalt fibre enhancing PA6 composites and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of polymer composite materials, in particular to a wear-resistant long basalt fiber reinforced PA6 composite material and a preparation method thereof. The composite material is prepared from the following raw materials by weight percentage, 1-20wt% solid lubricant, 10-40wt% long basalt fiber, 35-87wt% PA6 masterbatch and 2-5wt% processing aid, The processing aid is a silane coupling agent or/and a thermal stabilizer. Compared with the prior art, the beneficial effect of the present invention is: the wear-resistant long basalt fiber reinforced PA6 composite material prepared by the present invention has more balanced comprehensive properties in terms of mechanical properties and friction properties, strong wear resistance, and comprehensive properties Excellent, long service life, simple and efficient preparation method, easy industrial production, and has popularization value.

Description

A kind of wear-resistant long basalt fiber reinforced PA6 composite material and preparation method thereof

technical field

The invention belongs to the field of polymer composite materials, in particular to a wear-resistant long basalt fiber reinforced PA6 composite material and a preparation method thereof.

Background technique

Nylon (PA) is a widely used engineering plastic, which has the advantages of high strength, high wear resistance, oil resistance, weak acid resistance, self-lubrication, insulation and easy processing, but the molecular chain of PA contains a large number of polar amide groups. Agglomerates, resulting in high water absorption of PA, poor dimensional stability of the product, and reduced mechanical properties and wear resistance. In addition, the strength and rigidity of nylon are far inferior to metals. In some special applications, such as mining machinery, transmission equipment, transmission parts, etc., the serious lack of wear resistance greatly limits the application of nylon composite materials. In order to improve the wear resistance of nylon composite materials, fillers such as wear-resistant agents and reinforcing fibers need to be added for modification. Patent CN201510213124.2 uses reinforcing fiber, hydrophobic material, wear-resistant agent, lubricant, anti-ultraviolet light absorber, antioxidant and compatibilizer to modify nylon resin to obtain a high-strength, low-hygroscopic, weather-resistant , self-lubricating, wear-resistant nylon composite material and its preparation method; patent CN201310258531.6 uses aramid pulp in-situ polymerization modification to improve the interfacial adhesion between aramid fiber and PA6, and improves the mechanical properties and wear resistance of the composite material Performance; patent CN201510191484.7 adopts ethylene/vinyl alcohol copolymer to activate and coat the surface of the reinforcement, improve the compatibility between the reinforcement and PA6, and improve the heat resistance and sliding wear resistance of the material by adding nano-alumina Performance and fretting resistance, and carbon black is added to further improve the wear resistance and UV resistance of the material. The reinforcing materials of the above patents are commonly used glass fibers, carbon fibers or aramid fibers, and most of them exist in the form of short fibers, which cannot give full play to the reinforcing effect of the fibers. In addition, there are problems such as cumbersome preparation methods, complex material components, and low cost performance.

Long fiber reinforced thermoplastics (LFRT) is a new type of fiber reinforced technology that has developed rapidly in recent years. During the preparation of LFRT, the degree of fiber damage and fracture is minimized. LFRT has better mechanical and thermal properties than conventional short fiber reinforced thermoplastics, and the long fibers are intertwined to form a fiber skeleton, which can limit anisotropic shrinkage, significantly reduce warpage, and improve product dimensional stability and mechanical properties. properties, friction and wear properties, etc. Basalt fiber is a new type of highly competitive new high-performance reinforcing fiber developed after high-performance fibers such as carbon fiber, aramid fiber, and ultra-high molecular weight polyethylene fiber. In addition to its characteristics of high strength and high modulus , It also has excellent properties such as good high temperature resistance, good oxidation resistance, radiation resistance, good heat and sound insulation, good filterability, high compression resistance and shear strength, and is suitable for use in various environments. Applying basalt fiber to nylon reinforced materials can give full play to the performance advantages of basalt fiber, greatly improve the comprehensive properties of nylon matrix such as wear resistance and mechanical properties, and help expand the application range of nylon composite materials.

Filling modification of solid lubricants is another important way to improve the friction and wear properties of polymer matrix composites. Solid lubricants can form a stable lubricating film during the friction process, which is beneficial to reduce the friction coefficient and wear rate of materials. As an engineering plastic filler, the solid lubricant with a layered structure is easily detached from the polymer surface layer into abrasive particles by the pressure and movement between the friction couple and is ground thin and small, and fills the pits on the surface of the friction material. It has a homogenizing effect on the frictional contact. With the continuous accumulation of solid lubricants, a discontinuous transfer film is gradually formed on the friction surface. The good contact state between the films can improve the unevenness of the surface temperature and effectively inhibit high-temperature wear. Therefore, the use of solid lubricants as long basalt fiber reinforced PA6 composite fillers can further improve the tribological properties of PA6 composites.

The invention provides a wear-resistant long basalt fiber reinforced PA6 composite material and a preparation method thereof. The basalt fiber/PA6 composite material of the present invention not only takes into account the good mechanical properties reinforced by long basalt fibers, but also has excellent wear resistance; the preparation method of the present invention is simple, the fibers are fully impregnated, easy to produce continuously, and has good industrial application prospect.

Contents of the invention

In order to overcome the performance defects and deficiencies of the PA6 composite material, the invention provides a wear-resistant long basalt fiber reinforced PA6 composite material and a preparation method thereof.

The present invention is achieved through the following technical solutions: a wear-resistant long basalt fiber reinforced PA6 composite material is prepared from the following raw materials in weight percentage, 1-20wt% solid lubricant, 10-40wt% long basalt fiber, 35-87wt% of PA6 masterbatch and 2-5wt% of processing aid, said processing aid being silane coupling agent or/and heat stabilizer.

Preferably, the solid lubricant is polytetrafluoroethylene, molybdenum disulfide, graphite, paraffin or graphene.

In order to further illustrate the technical solution of the present invention, the present invention provides a preparation method of wear-resistant long basalt fiber reinforced PA6 composite material, which uses the above-mentioned raw materials, and the preparation process is: long basalt fiber is formed from the long basalt fiber on the support The fiber roll is drawn out and unfolded, and then introduced to the impregnation roller in the temperature-controlled impregnation mold through the guide roller and the limit guide roller. The extruder extrudes the PA6 masterbatch, solid lubricant and processing aid into the temperature-control impregnation mold. Adjust the temperature in the temperature-controlled impregnation mold and the speed of the traction roller. The impregnated fiber bundle enters the pressure roller in the cooling water tank through the guide roller at the entrance of the cooling water tank for cooling. After granulation and drying, the wear-resistant and long-lasting Basalt fiber reinforced PA6 composite material.

During specific implementation, the temperature inside the temperature-controlled dipping mold is 225-250° C., and the pulling speed of the basalt fiber is 5-35 mm/s. The optimal temperature and speed can ensure that the PA6 masterbatch, solid lubricant and processing aid are fully mixed in the molten state, and make the fibers and impregnated materials evenly impregnated.

In order to fully and uniformly impregnate the fibers with the impregnating material, preferably, the installation direction of each impregnating roller is perpendicular to the moving direction of the fiber bundle, and the adjacent impregnating rollers are cross-fitted up and down. In a specific application, the number of the dipping rolls is 2-8.

Compared with the prior art, the beneficial effects of the present invention are: the friction coefficient and the wear rate of the solid lubricant modified long basalt fiber reinforced PA6 composite material provided by the present invention are compared with the unmodified long basalt fiber/PA composite material Low, solid lubricants effectively improve the tribological properties of long basalt fiber reinforced PA6 composites; the prepared PA6 composites have more balanced comprehensive properties in terms of mechanical properties and friction properties, strong wear resistance, and excellent comprehensive properties , long service life, simple and efficient preparation method, easy industrial production, and has popularization value.

Description of drawings

Figure 1 is a schematic structural view of the device used in the preparation method of the present invention. In the figure: 1-stand, 2-long fiber roll, 3-guide roller, 4-limit guide roller, 5-extruder, 6-temperature-controlled impregnation mold, 7-impregnation roller, 8-cooling water tank, 9- Guide roller, 10-drawing roller, 11-granulator, 12-pressure roller.

Fig. 2 is a scanning electron micrograph of the impact section of the wear-resistant long basalt fiber reinforced PA6 composite material prepared in Example 1 of the present invention. The diagram shows that the interface between the fiber and the resin matrix is firmly bonded, indicating that the preparation method of the wear-resistant long basalt fiber reinforced PA6 composite material provided by the present invention can fully impregnate the fiber.

Fig. 3 is a scanning electron micrograph of the impact section of the chopped basalt fiber reinforced PA6 composite material obtained in Comparative Example 1 of the present invention.

detailed description

Referring to Fig. 1, the preparation method of the present invention adopts following device to complete, and described device comprises the support 1 that some long fiber rolls 2 are installed, the temperature control impregnation mold 6 that is connected with extruder 5 outlet ends, installs successively The guide roller 3 and the limit guide roller 4 between the bracket 1 and the temperature-controlling impregnation mold 6, several impregnation rollers 7 installed in the temperature-control impregnation mold 6, the cooling water tank 8 arranged at the outlet end of the temperature-control impregnation mold 6, and installed The pressure roller 12 in the cooling water tank 8, the two guide rollers 9 installed at the entrance and exit of the cooling water tank 8, the traction roller 10 installed at the exit of the cooling water tank 8 and the pelletizer installed at the discharge end of the traction roller 10 11.

The present invention will be described in further detail below in conjunction with specific examples, and the following examples are only used to illustrate the present invention, and are not intended to limit the present invention.

Example 1

Graphite (5wt%), PA6 masterbatch (60wt%) and gamma-isocyanate propyltriethoxysilane (5wt%) are added from the feeding port of extruder 5, fully Mix (a total of 6 impregnating rollers 7, mold temperature 240°C), then pull out the continuous basalt fiber from the temperature-controlled impregnating mold 6 at 15mm/sec, control the basalt fiber content to 30wt%, and pass through water cooling and pelletizing machine successively 11 Granulating and drying, the wear-resistant long basalt fiber reinforced PA6 composite material with a length of 10mm is obtained. The resulting composite material was injection molded to obtain a standard sample, and the mechanical and friction and wear properties of the wear-resistant basalt fiber reinforced PA6 composite material were tested, as shown in Table 1.

Example 2

Graphite (10wt%), PA6 masterbatch (58wt%) and gamma-glycidyl etheroxypropyl trimethoxysilane (2wt%) are added from the feeding port of extruder 5, fully Mix (a total of 6 impregnating rollers 7, mold temperature 240°C), then pull out the continuous basalt fiber from the temperature-controlled impregnating mold 6 at 15mm/sec, control the basalt fiber content to 30wt%, and pass through water cooling and pelletizing machine successively 11 Granulating and drying, the wear-resistant long basalt fiber reinforced PA6 composite material with a length of 10mm is obtained. The resulting composite material was injection molded to obtain a standard sample, and the mechanical and friction and wear properties of the wear-resistant basalt fiber reinforced PA6 composite material were tested, as shown in Table 1.

Example 3

Graphite (15wt%), PA6 masterbatch (50wt%) and gamma-aminopropyltriethoxysilane (5wt%) are added from the feeding port of extruder 5, fully mix in temperature control dipping mold 6 ( There are 6 impregnating rolls 7, the mold temperature is 240°C), and then the continuous basalt fiber is pulled out from the temperature-controlled impregnating mold 6 at 15mm/sec, and the content of the basalt fiber is controlled to be 30wt%. granules and dried to obtain a wear-resistant long basalt fiber reinforced PA6 composite material with a length of 10 mm. The resulting composite material was injection molded on an injection molding machine to obtain a standard sample, and the mechanical and friction and wear properties of the wear-resistant long basalt fiber reinforced PA6 composite material were tested, as shown in Table 1.

Example 4

Graphite (5wt%), PA6 masterbatch (60wt%) and the mixture of γ-aminopropyltriethoxysilane and dilauryl thiodipropionate (2wt%, respectively 1wt%, 1wt%) were extruded The feeding port of the machine 5 is added, fully mixed in the temperature-controlled impregnation mold 6 (a total of 6 impregnation rollers 7, the mold temperature is 240 ° C), and then the continuous basalt fiber (long-fiber basalt) is impregnated from the temperature control at 5 mm/s Pull out from the mold 6, control the basalt fiber content to 33wt%, and sequentially pass through water cooling, granulator 11 granulation, and drying to obtain a wear-resistant long basalt fiber reinforced PA6 composite material with a length of 10mm.

Example 5

Add paraffin (20wt%), PA6 masterbatch (58wt%) and gamma-glycidyl etheroxypropyl trimethoxysilane (3wt%) from the feeding port of extruder 5, fully Mix (two impregnating rollers 7, mold temperature 225°C), then pull out the continuous basalt fiber from the temperature-controlled impregnating mold 6 at 15mm/sec, control the basalt fiber content to 19wt%, and pass through water cooling and pelletizing machine successively 11 Granulating and drying, the wear-resistant long basalt fiber reinforced PA6 composite material with a length of 10mm is obtained.

Example 6

Graphene (20wt%), PA6 masterbatch (35wt%) and gamma-isocyanate propyltriethoxysilane (5wt%) are added from the feeding port of extruder 5, in the temperature control dipping mold 6 Fully mix (4 impregnating rollers 7, mold temperature 250°C), then pull out the continuous basalt fiber from the temperature-controlled impregnating mold 6 at 35mm/sec, control the basalt fiber content to 40wt%, and then pass through water cooling and pelletizing successively Machine 11 granulates and dries to obtain a wear-resistant long basalt fiber reinforced PA6 composite material with a length of 10 mm.

Example 7

Molybdenum disulfide (20wt%), PA6 masterbatch (50wt%), 4-hydroxyoctadecanoic acid anilide (5wt%) are added from the feeding port of extruder 5, fully in the temperature control dipping mold 6 Mix (a total of 8 impregnating rollers 7, mold temperature 230°C), then pull out the continuous basalt fiber from the temperature-controlled impregnating mold 6 at 20mm/sec, control the basalt fiber content to 25wt%, and pass through water cooling and pelletizing machine successively 11 Granulate and dry to obtain a wear-resistant long basalt fiber reinforced PA6 composite material with a length of 5 mm.

Example 8

Add polytetrafluoroethylene (1wt%), PA6 masterbatch (87wt%) and triphenyl phosphite (2wt%) from the feeding port of extruder 5, fully mix in temperature control dipping mold 6 (dipping roll 7, a total of 7, mold temperature 245 ℃), then the continuous basalt fiber is pulled out from the temperature control impregnation mold 6 at 25mm/s, the content of the basalt fiber is controlled to be 10wt%, and it is cooled by water, granulated by a pelletizer 11, After drying, a wear-resistant long basalt fiber reinforced PA6 composite material with a length of 20 mm is obtained.

Each raw material listed in the present invention can realize the present invention, and the upper and lower limits of each raw material and its interval value can realize the present invention, and the embodiments are not enumerated here one by one.

Table 1 shows the mechanical properties and friction properties of the wear-resistant basalt fiber reinforced PA6 composites obtained in Examples 1, 2, and 3. Comparing various data, it can be concluded that the wear-resistant long basalt fiber reinforced PA6 composite material prepared by the present invention has advantages such as high strength, high toughness, low friction coefficient, and strong wear resistance. The basalt fiber reinforced PA6 composite material has better comprehensive performance in terms of mechanical properties and friction and wear properties, so it has promotion value.

Table 1

Note: The friction coefficient and wear rate of the sample are measured on the HT-1000 friction and wear testing machine, and the test conditions are: normal temperature, 20N, 1000r/min. Comparative example 1 is: after premixing 20wt% chopped basalt fiber (diameter 7um, length 50um) and 80wt% PA6 particles, melt blending and extruding through an extruder at 230 ° C, cooling and pelletizing, drying to obtain chopped basalt fibers Basalt fiber reinforced PA6 composite material, the gained composite material is injection-molded to obtain a standard sample, and the mechanical properties and the friction and wear properties of the composite material are obtained by testing; Comparative example 2 is: 30wt% chopped basalt fiber (diameter 7um, long 50um) and 70wt% % PA6 particles are pre-mixed, melt blended and extruded through an extruder at 230 ° C, cooled and pelletized, and then dried to obtain chopped basalt fiber reinforced PA6 composite materials. The obtained composite materials are injection molded to obtain standard specimens, and tested to obtain Mechanical properties and friction and wear properties of composite materials.

Claims (4)

1. a kind of preparation method of wear-resisting long basalt fibre enhancing PA6 composites, it is characterised in that the preparation method Composite is prepared by the raw material of following weight percents：1-20wt% kollag, the 10-40wt% long Black Warrior Rock fiber, 35-87wt% PA6 master batches and 2-5wt% processing aid, the processing aid are silane coupler or/and heat Stabilizer, the kollag are polytetrafluoroethylene (PTFE), molybdenum disulfide, graphite, paraffin or graphene；

The preparation method employs following devices and prepared by technique：

Described device includes being provided with some long fibre volumes（2）Support（1）, with extruder（5）The temperature control that the port of export is connected Impregnation mold（6）, support is installed on successively（1）With temperature control impregnation mold（6）Between deflector roll（3）With spacing deflector roll（4）, installation In temperature control impregnation mold（6）Interior some dip rolls（7）, it is arranged at temperature control impregnation mold（6）The bosh of the port of export（8）, It is installed on bosh（8）Interior pressure roller（12）, it is respectively arranged in bosh（8）Porch and two guide rollers in exit （9）, it is installed on bosh（8）The carry-over pinch rolls in exit（10）And it is installed on carry-over pinch rolls（10）The pelleter of discharge end （11）；

The preparation technology is：By long basalt fibre from support（1）On long fibre volume（2）Middle extraction simultaneously deploys, by leading Roller（3）With spacing deflector roll（4）It is incorporated into temperature control impregnation mold（6）Interior dip roll（7）On, extruder（5）By PA6 master batches, admittedly Body lubricant and processing aid are squeezed into temperature control impregnation mold（6）It is interior, regulate and control temperature control impregnation mold（6）Interior temperature and lead Pick-up roll（10）Speed, the fibre bundle after dipping passes through bosh（8）The guide roller of porch（9）Enter bosh （8）Interior pressure roller（12）On cooled down, in pelleter（11）Middle granulation, wear-resisting long basalt fibre enhancing is then obtained after drying PA6 composites.

2. a kind of preparation method of wear-resisting long basalt fibre enhancing PA6 composites according to claim 1, its feature It is, the temperature control impregnation mold（6）Interior temperature is 225 ~ 250 DEG C, and the pulling speed of basalt fibre is 5 ~ 35mm/s.

3. a kind of preparation method of wear-resisting long basalt fibre enhancing PA6 composites according to claim 2, its feature It is, each dip roll（7）Installation direction and fibre bundle moving direction it is perpendicular, adjacent dip roll（7）Between in up and down Intersect and coordinate.

4. a kind of preparation method of wear-resisting long basalt fibre enhancing PA6 composites according to claim 3, its feature It is, the dip roll（7）Number be 2 ~ 8.