阅读说明：本技术 一种阻燃玻璃纤维增强聚丙烯复合材料及其制备方法 (Flame-retardant glass fiber reinforced polypropylene composite material and preparation method thereof ) 是由 田方 余成伟 李国东 张重庆 石允慧 于 2019-09-18 设计创作，主要内容包括：本发明公开了一种阻燃玻璃纤维增强聚丙烯复合材料及其制备方法,由以下重量组分制得：高熔体强度聚丙烯100份、普通聚丙烯30-50份、玻璃纤维30-50份、聚硼硅氧烷2-5份、阻燃剂4-7份、阻燃协效剂2-4份、相容剂3-5份、物理发泡剂8-15份、润滑剂0.3-0.6份、光稳剂0.3-0.6份、抗氧剂0.3-0.6份。通过使用高熔体强度聚丙烯、普通聚丙烯、玻璃纤维、聚硼硅氧烷等原料并结合特殊的制备工艺可制备出阻燃、物理发泡挤出玻璃纤维增强聚丙烯复合材料的制备及方法,发泡后的复合材料表观密度为0.06-0.15g/cm<Sup>3</Sup>,发泡数量达到10<Sup>7</Sup>-10<Sup>9</Sup>个/cm<Sup>3</Sup>,泡孔直径达到40-70微米,有90%的泡孔直径可达40-55微米水平,阻燃性能可达UL-V0等级,可广泛应用到汽车、家电、包装等各个领域。(The invention discloses a flame-retardant glass fiber reinforced polypropylene composite material and a preparation method thereof, wherein the flame-retardant glass fiber reinforced polypropylene composite material is prepared from the following components in parts by weight: 100 parts of high melt strength polypropylene, 30-50 parts of common polypropylene, 30-50 parts of glass fiber, 2-5 parts of polyborosiloxane, 4-7 parts of flame retardant, 2-4 parts of flame retardant synergist, 3-5 parts of compatilizer, 8-15 parts of physical foaming agent, 0.3-0.6 part of lubricant, 0.3-0.6 part of light stabilizer and 0.3-0.6 part of antioxidant. The preparation method of the flame-retardant and physically foamed and extruded glass fiber reinforced polypropylene composite material can be prepared by using the raw materials of high melt strength polypropylene, common polypropylene, glass fiber, polyborosiloxane and the like and combining a special preparation process, and the apparent density of the foamed composite material is 0.06-0.15g/cm 3 The foaming amount reaches 10 7 ‑10 9 per cm 3 the diameter of the foam pores reaches 40-70 microns, 90 percent of the foam pores can reach the level of 40-55 microns, the flame retardant property can reach the UL-V0 grade, and the flame retardant can be widely applied to various fields of automobiles, household appliances, packaging and the like.)

1. the flame-retardant glass fiber reinforced polypropylene composite material is characterized by being prepared from the following components in parts by weight: 100 parts of high melt strength polypropylene, 30-50 parts of common polypropylene, 30-50 parts of glass fiber, 2-5 parts of polyborosiloxane, 4-7 parts of flame retardant, 2-4 parts of flame retardant synergist, 3-5 parts of compatilizer, 8-15 parts of physical foaming agent, 0.3-0.6 part of lubricant, 0.3-0.6 part of light stabilizer and 0.3-0.6 part of antioxidant.

2. The flame retardant glass fiber reinforced polypropylene composite material according to claim 1, wherein the high melt strength polypropylene is one or more of homo-polypropylene or co-polypropylene, and the melt index is 0.1-3g/10min at 230 ℃ under 2.16 kg.

3. The flame-retardant glass fiber reinforced polypropylene composite material according to claim 1, wherein the ordinary polypropylene is one or more of homo-polypropylene or co-polypropylene, and the melt index is 26-100g/10min at 230 ℃ under 2.16 kg.

4. The flame retardant glass fiber reinforced polypropylene composite of claim 1, wherein the glass fiber is an alkali-free glass fiber and has a diameter of 10-13 μm.

5. The flame retardant glass fiber reinforced polypropylene composite material according to claim 1, wherein the polyborosiloxane is prepared by the following components by weight:

(1) Preparation of Polyborosiloxane intermediates

Firstly, weighing 100 parts of triethoxyborane and 3-5 parts of silicon tetrachloride in a 5000ml three-neck flask, placing the three-neck flask in a heating jacket for heating and stirring, keeping the temperature at 95-110 ℃ and the stirring speed at 280-350 r/min, then simultaneously and slowly adding 0.012-0.015 part of metallocene catalyst titanocene dichloride and 0.030-0.035 part of cocatalyst triethylaluminum, reacting for 16-18 hours after the catalyst is added, and keeping the reaction process in a heating and stirring state all the time to obtain a polyborosiloxane intermediate;

Wherein the time for slowly adding the metallocene catalyst and the cocatalyst is 90-120 minutes; nitrogen is required to be introduced for protection in the whole process;

(2) Preparation of Polyborosiloxane

Weighing 100-115 parts of silicon tetrachloride and excessive distilled water, slowly adding the silicon tetrachloride and the excessive distilled water into a three-neck flask, reacting for 16-18 hours after the silicon tetrachloride and the excessive distilled water are added, finally obtaining a hydrolysate, washing the hydrolysate with deionized water, and finally performing reduced pressure distillation at the temperature of 135-150 ℃ to remove small molecules, thus obtaining liquid polyborosiloxane;

wherein, the time for slowly adding the silicon tetrachloride and the excessive distilled water in the second step is 60-90 minutes, and nitrogen is required to be introduced for protection in the whole process.

6. The flame retardant glass fiber reinforced polypropylene composite material according to claim 1, wherein the flame retardant is one or more of decabromodiphenylethane or octabromobisphenol S ether; the flame-retardant synergist is one or more of antimony trioxide or antimony pentoxide.

7. The flame retardant glass fiber reinforced polypropylene composite of claim 1, wherein the compatibilizer is polypropylene grafted maleic anhydride.

8. The flame retardant glass fiber reinforced polypropylene composite of claim 1, wherein the physical blowing agent is one or more of carbon dioxide or nitrogen.

9. the flame retardant glass fiber reinforced polypropylene composite material according to claim 1, wherein the lubricant is one or more of zinc stearate and calcium stearate; the antioxidant is compounded by tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite in a mass ratio of 1: 1; the light stabilizer is a compound of 2, 2, 6, 6-tetramethyl-4-piperidyl stearate and 3, 5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl ester, and the mass ratio of the two components is 1: 1.

10. a method for preparing a flame retardant glass fiber reinforced polypropylene composite according to any one of claims 1 to 9, comprising the steps of:

(1) Preparing polyborosiloxane;

(2) 100 parts of high melt strength polypropylene, 30-50 parts of common polypropylene, 30-50 parts of glass fiber, 2-5 parts of polyborosiloxane, 4-7 parts of flame retardant, 2-4 parts of flame retardant synergist, 3-5 parts of compatilizer, 0.3-0.6 part of lubricant, 0.3-0.6 part of light stabilizer and 0.3-0.6 part of antioxidant are added into a high-speed mixer to be uniformly mixed, the rotating speed of the high-speed mixer is 500-1000RPM, the mixing time is 10-15min, the mixed materials are put into a double-screw extruder to be melted and plasticized, and 8-15 parts of physical foaming agent is introduced into the tail end of the double-screw extruder, wherein the temperature of the double-screw extruder is 200-240 ℃;

(3) Adding the melt containing the physical foaming agent into a special extrusion foaming machine for physical foaming, wherein the thickness of a die head of the extrusion foaming machine can be adjusted within 1.0-3.0 mm;

(4) and (3) the foamed sheet is discharged from the extrusion foaming machine and then enters a three-roller machine for transmission, and finally, the foamed sheet is sliced and packaged by a cutter.

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a flame-retardant glass fiber reinforced polypropylene composite material and a preparation method thereof.

Background

Polypropylene (PP) is a crystalline polymer with a regular structure, is usually white granules or powder, and is a tasteless, nontoxic and light thermoplastic resin. Polypropylene has the advantages of easy processing, good impact strength, flexibility and electrical insulation, and the like, has good chemical resistance, and has wide application in the automobile industry, household appliances, electronics, packaging, building materials, furniture and other aspects.

EPP (Expanded Polypropylene) is a semi-high crystalline polymer/gas composite material with excellent performance, and becomes a novel environment-friendly compression-resistant buffering and heat-insulating material which is the fastest growing at present due to unique and superior performance. The EPP product has excellent shock resistance and energy absorption performance, high recovery rate after deformation, good heat resistance, chemical resistance, oil resistance and heat insulation; meanwhile, the weight of the product is light, and the product weight can be greatly reduced; in addition, EPP is also an environment-friendly material, is easily subjected to beta degradation, and PP foam is easily recycled, and is superior to other foam materials in environmental friendliness, thus being called "green" foam. Due to the excellent performance, EPP becomes a novel foam material with higher application value and market potential after polystyrene (EPS) and polyurethane (EPU) foam materials. EPP produced by the conventional method is a linear semicrystalline polymer, and the molecular chain is less branched and the molecular weight distribution is relatively narrow, which results in its softening point and melting point being close to each other. Before the temperature reaches the melting point, the melt basically does not flow, and when the temperature exceeds the melting point, the strength of the melt is sharply reduced, and the melt is difficult to enclose gas; in addition, the polypropylene is transformed from a molten state to a crystalline state, which releases a large amount of heat and takes a long time to transform the melt into a solid; in addition, the polypropylene has high air permeability, and foaming gas is easy to escape. Therefore, the temperature range suitable for polypropylene foaming is narrow, the foaming process is difficult to control, and the cell wall breakage, gas escape, cell collapse and cell combination in the foaming process are easy to cause. Therefore, to obtain high-quality polypropylene foam, it is critical to improve the melt strength.

the polyborosiloxane is a novel organic high molecular material, is a polymer obtained by introducing boron into a silicone skeleton of polysiloxane, has more excellent high temperature resistance and flame retardant property compared with common organic siloxane, and can effectively assist the dispersion of a flame retardant and a flame retardant synergist by adding the polyborosiloxane into a polypropylene material to play a good flame retardant synergistic effect.

Chinese patent (CN 106279965A) discloses a physically foamed filled flame-retardant polypropylene material and a preparation method thereof, the flame retardant and the flame-retardant synergist used in the material have high content, the material is injection-molded and foamed, and the foaming multiplying power is low (the density after foaming is 0.68-1.13 g/cm)³)。

Chinese patent (CN 102372855A) discloses a supercritical method for preparing pre-foamed polypropylene, which applies a supercritical fluid method, utilizes a physical foaming agent to carry out melt strength increasing treatment on polypropylene, and prepares a pre-foamed polypropylene material through a special pre-foaming process; the preparation method mainly adopts PP and PE for crosslinking, and simultaneously increases the melting range by adding inorganic filler and elastomer to achieve the purpose of increasing the melt strength, but the crosslinking degree and the like are uncontrollable, so the uniformity and the stability of the foam pores of the prepared foam material are a problem.

Disclosure of Invention

the invention aims to make up the defects of the prior art and provides a flame-retardant glass fiber reinforced polypropylene composite material and a preparation method thereof, the flame-retardant and physically foamed extruded glass fiber reinforced polypropylene composite material can be prepared by using raw materials such as high melt strength polypropylene, common polypropylene, glass fiber, polyborosiloxane, flame retardant, flame-retardant synergist, compatilizer, physical foaming agent, lubricant, light stabilizer, antioxidant and the like and combining a special preparation process, and the apparent density of the foamed composite material is 0.06-0.15g/cm³The foaming amount reaches 10⁷-10⁹Per cm³the diameter of the foam pores reaches 40-70 microns, 90 percent of the foam pores can reach the level of 40-55 microns, the flame retardant property can reach the UL-V0 grade, and the flame retardant can be widely applied to various fields of automobiles, household appliances, packaging and the like.

In order to achieve the above object, the present invention provides the following technical solutions:

The flame-retardant glass fiber reinforced polypropylene composite material is prepared from the following components in parts by weight: 100 parts of high melt strength polypropylene, 30-50 parts of common polypropylene, 30-50 parts of glass fiber, 2-5 parts of polyborosiloxane, 4-7 parts of flame retardant, 2-4 parts of flame retardant synergist, 3-5 parts of compatilizer, 8-15 parts of physical foaming agent, 0.3-0.6 part of lubricant, 0.3-0.6 part of light stabilizer and 0.3-0.6 part of antioxidant.

The high melt strength polypropylene is one or more than one of homo-polypropylene or co-polypropylene, and the melt index is 0.1-3g/10min at 230 ℃ and under the condition of 2.16 kg.

The common polypropylene is one or more than one of homo-polypropylene or co-polypropylene, and the melt index is 26-100g/10min at 230 ℃ under the condition of 2.16 kg.

The glass fiber is alkali-free glass fiber and has a diameter of 10-13 μm.

The polyborosiloxane is prepared from the following components in parts by weight:

(1) Preparation of Polyborosiloxane intermediates

Firstly, weighing 100 parts of triethoxyborane and 3-5 parts of silicon tetrachloride in a 5000ml three-neck flask, placing the three-neck flask in a heating jacket for heating and stirring, keeping the temperature at 95-110 ℃ and the stirring speed at 280-350 r/min, then simultaneously and slowly adding 0.012-0.015 part of metallocene catalyst titanocene dichloride and 0.030-0.035 part of cocatalyst triethylaluminum, reacting for 16-18 hours after the catalyst is added, and keeping the reaction process in a heating and stirring state all the time to obtain a polyborosiloxane intermediate;

Wherein the time for slowly adding the metallocene catalyst and the cocatalyst is 90-120 minutes; nitrogen is required to be introduced for protection in the whole process;

(2) Preparation of Polyborosiloxane

then weighing 100-115 parts of silicon tetrachloride and excess distilled water (such as 1000 parts), slowly adding into a three-neck flask, reacting for 16-18 hours after adding, finally obtaining a hydrolysate, washing the hydrolysate with deionized water, and finally performing reduced pressure distillation at the temperature of 135-150 ℃ to remove small molecules, thus finally obtaining liquid polyborosiloxane;

Wherein, the time for slowly adding the silicon tetrachloride and the excessive distilled water in the second step is 60 to 90 minutes. The whole process needs to be protected by nitrogen.

the flame retardant is one or more of decabromodiphenylethane or octabromobisphenol S ether.

the flame-retardant synergist is one or more of antimony trioxide or antimony pentoxide.

The compatilizer is polypropylene grafted maleic anhydride.

the physical foaming agent is one or more of carbon dioxide or nitrogen.

The lubricant is one or more of zinc stearate and calcium stearate.

The antioxidant is compounded by tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester and tris (2, 4-di-tert-butylphenyl) phosphite in a mass ratio of 1: 1.

the light stabilizer is a compound of 2, 2, 6, 6-tetramethyl-4-piperidyl stearate and 3, 5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl ester, and the mass ratio of the two components is 1: 1.

The preparation method of the flame-retardant glass fiber reinforced polypropylene composite material comprises the following steps:

(1) preparing polyborosiloxane;

(2) 100 parts of high melt strength polypropylene, 30-50 parts of common polypropylene, 30-50 parts of glass fiber, 2-5 parts of polyborosiloxane, 4-7 parts of flame retardant, 2-4 parts of flame retardant synergist, 3-5 parts of compatilizer, 0.3-0.6 part of lubricant, 0.3-0.6 part of light stabilizer and 0.3-0.6 part of antioxidant are added into a high-speed mixer to be uniformly mixed, the rotating speed of the high-speed mixer is 500-1000RPM, the mixing time is 10-15min, the mixed materials are put into a double-screw extruder to be melted and plasticized, and 8-15 parts of physical foaming agent is introduced into the tail end of the double-screw extruder, wherein the temperature of the double-screw extruder is 200-240 ℃;

(3) adding the melt containing the physical foaming agent into a special extrusion foaming machine for physical foaming, wherein the thickness of a die head of the extrusion foaming machine can be adjusted within 1.0-3.0 mm;

(4) and (3) the foamed sheet is discharged from the extrusion foaming machine and then enters a three-roller machine for transmission, and finally, the foamed sheet is sliced and packaged by a cutter.

the invention has the advantages that:

1. The self-made polyborosiloxane can obviously improve the dispersion of the flame retardant and the flame retardant synergist and has good flame retardant and synergistic effects.

2. According to the invention, a good flame retardant effect can be achieved by adding a small amount of flame retardant and flame retardant synergist, and in addition, the compatibility of polypropylene and other flame retardants can be obviously improved by the compatilizer.

3. The invention is beneficial to improving the foaming effect by adding the glass fiber to increase the strength of the melt.

4. The invention has simple production process and is suitable for mass production.

Detailed Description

the technical scheme of the invention is further explained by combining the specific examples as follows:

The following examples are merely exemplary of the present invention, and the scope of the present invention is not limited thereto. The densities of the following examples and comparative examples were measured according to ISO 1183-1, the cell numbers and cell sizes were measured using a Scanning Electron Microscope (SEM), and the flame retardancy was measured according to UL-94 (1.6mm thickness).