阅读说明：本技术 一种用于汽车内饰的低voc玻纤增强聚丙烯复合材料及其制备方法 (Low-VOC glass fiber reinforced polypropylene composite material for automotive interior and preparation method thereof ) 是由 张祥洲 余学煌 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种用于汽车内饰的低VOC玻纤增强聚丙烯复合材料及其制备方法,属于高分子复合材料技术领域。按重量份数计,由以下组分制成：聚丙烯70-85份,无机填料25-35份,玻璃纤维20-28份,低VOC复合相容剂5-8份,抗氧剂1-4份,吸附剂2-3份。本发明通过控制引发体系及反应原料制备得到一种低VOC复合相容剂,另外结合一种复配吸附剂,不仅有效促进了玻璃纤维在聚丙烯中的均匀分散,使得玻璃纤维在聚丙烯中不浮纤,同时采用了一种分段分量预制母粒熔融搅拌的制备工艺,显著降低了最终制得玻纤增强聚丙烯复合材料中的VOC含量,对人体危害大大减弱,同时提升了材料的力学性能,在汽车制造领域具有很好的应用前景。(The invention discloses a low-VOC glass fiber reinforced polypropylene composite material for automotive interior and a preparation method thereof, belonging to the technical field of polymer composite materials. The composition is prepared from the following components in parts by weight: 70-85 parts of polypropylene, 25-35 parts of inorganic filler, 20-28 parts of glass fiber, 5-8 parts of low VOC composite compatilizer, 1-4 parts of antioxidant and 2-3 parts of adsorbent. The low-VOC composite compatilizer is prepared by controlling an initiation system and reaction raw materials, and is combined with a compound adsorbent, so that the uniform dispersion of glass fibers in polypropylene is effectively promoted, the glass fibers do not float in the polypropylene, meanwhile, a preparation process of melting and stirring segmented component prefabricated master batches is adopted, the VOC content in the finally prepared glass fiber reinforced polypropylene composite material is remarkably reduced, the harm to a human body is greatly reduced, the mechanical property of the material is improved, and the low-VOC composite compatilizer has a good application prospect in the field of automobile manufacturing.)

1. The low-VOC glass fiber reinforced polypropylene composite material for the automotive interior is characterized by being prepared from the following components in parts by weight:

70-85 Parts of Polypropylene (PP),

25-35 parts of an inorganic filler,

20-28 parts of glass fiber,

5-8 parts of a low VOC composite compatilizer,

1-4 parts of an antioxidant, namely,

2-3 parts of an adsorbent;

the preparation method of the low-VOC composite compatilizer comprises the following steps: and adding the copolymerized polypropylene resin, the grafting monomer and the antioxidant into a stirrer for mixing, adding the obtained mixture into a double-screw extruder, adding the initiator and the humic acid through side feeding, and performing melt extrusion at the temperature of 200-220 ℃ to obtain the low-VOC composite compatilizer.

2. The low-VOC glass fiber reinforced polypropylene composite material for automotive interiors according to claim 1, wherein the low-VOC composite compatilizer comprises the following raw materials in parts by weight: 60-75 parts of copolymerized polypropylene resin, 0.2-3.2 parts of grafting monomer, 0.3-0.5 part of antioxidant, 1-1.6 parts of initiator and 0.8-1.4 parts of humic acid.

3. The low-VOC glass fiber reinforced polypropylene composite material for automotive interiors according to claim 2, wherein the polypropylene copolymer resin is obtained by block copolymerization of PP and PE.

4. The low-VOC glass fiber reinforced polypropylene composite material for automotive interiors according to claim 2, wherein the grafting monomer is glycidyl methacrylate, and the grafting rate is 1.0-1.4%; the obtained low VOC composite compatilizer has a melt index of 95-120g/10min and a functional group content of 0.8-1.2GMA wt% under the conditions of 2.16kg and 190 ℃.

5. The low-VOC glass fiber reinforced polypropylene composite material for automotive interiors according to claim 2, wherein the initiator is a compound of di-tert-butyl peroxide and cumene hydroperoxide, and the mass ratio of the initiator to the hydrogen peroxide is (1.2-1.8): 3.

6. the low VOC glass fiber reinforced polypropylene composite material for automotive interior according to claim 1, wherein the glass fiber is alkali-free long glass fiber, has a length of 5-7mm, and has a diameter of 6-10 μm.

7. The low-VOC glass fiber reinforced polypropylene composite material for automotive interiors according to claim 1, wherein the adsorbent comprises 45-65% of molecular sieve, 2-5% of yttrium oxide and the balance of diatomite by mass percent.

8. A method for preparing the low VOC glass fiber reinforced polypropylene composite material of any one of claims 1-7, comprising the steps of:

1) weighing the raw materials according to a formula for later use;

2) mixing and stirring 1/3 polypropylene, half of adsorbent and 1/4 low VOC composite compatilizer, and then putting the mixture into a double-screw extruder for melt extrusion and granulation to obtain master batches;

3) placing the rest 2/3 polypropylene, inorganic filler, 1/2 low VOC composite compatilizer and antioxidant into a stirrer, and stirring at a high speed of 1000r/min and 800-110 ℃ for 5-10 min;

4) and (3) putting the master batch obtained in the step 2), the mixture obtained in the step 3), the rest half of the adsorbent and the rest 1/4 low-VOC composite compatilizer into a double-screw extruder, adding glass fiber through side feeding, performing melt extrusion granulation, and cooling to obtain the low-VOC glass fiber reinforced polypropylene composite material.

9. The method for preparing the low-VOC glass fiber reinforced polypropylene composite material as claimed in claim 8, wherein the melting temperature of the twin-screw extruder in the step 2) is 160-200 ℃.

10. The method for preparing the low-VOC glass fiber reinforced polypropylene composite material according to claim 8, wherein the melting temperature of the twin-screw extruder in the step 4) is set as follows: the temperature of the first section is 100-.

Technical Field

The invention belongs to the technical field of polymer composite materials, and particularly relates to a low-VOC glass fiber reinforced polypropylene composite material for automotive interior and a preparation method thereof.

Background

At present, the environmental pollution in automobiles in China is serious, and VOC (volatile organic compounds) in the automobiles mainly come from plastic parts of automobile carpets and instrument panels, roof felts, seats and glue used in other decoration. Volatile components such as organic solvents, auxiliaries and the like contained in materials such as plastics and rubber parts, fabrics, paint coatings, heat insulation materials, adhesives and the like used by automobiles are released into the environment in the automobiles, and air pollution is caused. Because the space of the automobile is narrow and small, the air quantity in the automobile is not much, and the airtightness of the automobile is good, the harm degree of the exceeding of the harmful gas in the automobile to human bodies is larger than that of the exceeding of the harmful gas in the house.

At present, the direct standards of VOC related to automobiles in China are HJ/T400 sampling and measuring methods of volatile organic compounds and aldehyde ketone substances in automobiles and GB/T27630 evaluation guidelines for air quality in passenger automobiles. The former stipulates a sampling and measuring method of volatile organic compounds and aldehyde ketone substances in M-type (passenger carrying) vehicles and N-type (cargo carrying) vehicles, but the standard is only suitable for sampling in vehicles under the conditions of static state, constant temperature and constant humidity of the vehicles, and indexes and limit values of air pollutants in the vehicles are not stipulated; the later stipulates the limit standards of each VOC pollutant in the air in the automobile, but the limit standards only aim at the VOC standard of the whole automobile, the raw materials and parts of the automobile have no relevant national standards, and the VOC emission problem is not controlled from the source.

The automobile enterprises can reduce the VOC volatilization of the automobile from the design and production source by controlling the VOC of the parts and materials, which is undoubtedly the most direct and effective means, so that the design of the low-VOC composite material for the automobile interior is very important. In recent years, glass Fiber Reinforced Polypropylene (FRP) is widely used in the field of automobile manufacturing as a general thermoplastic reinforced composite material due to its advantages of high elastic modulus, high strength, high thermal deformation temperature, good stability and the like, but in the preparation process of the FRP, more organic solvents and auxiliaries are used to ensure high performance, and the content of VOC in the composite material is inevitably increased by the solvents and auxiliaries, so the problem of high content of VOC in the automobile is still needed to be solved.

Disclosure of Invention

The invention provides a low VOC glass fiber reinforced polypropylene composite material for automotive interiors and a preparation method thereof, aiming at the problems that volatile components such as organic solvents, auxiliary agents and the like contained in the materials used for the automotive interiors are released to the environment in a vehicle and harm is caused to human health. The low-VOC composite compatilizer is prepared by controlling the initiation system and the reaction raw materials, the composite compatilizer not only has low VOC content, but also can effectively promote the uniform dispersion of glass fibers in polypropylene, and in addition, the low-VOC composite compatilizer is combined with a compound adsorbent which can further absorb residual VOC, and the VOC content in the finally prepared glass fiber reinforced polypropylene composite material is remarkably reduced by the low-VOC composite compatilizer and the compound adsorbent.

The invention is realized by the following technical means:

the invention provides a low VOC glass fiber reinforced polypropylene composite material for automotive interior, which is prepared from the following components in parts by weight:

70-85 Parts of Polypropylene (PP),

25-35 parts of an inorganic filler,

20-28 parts of glass fiber,

5-8 parts of a low VOC composite compatilizer,

1-4 parts of an antioxidant, namely,

2-3 parts of an adsorbent.

Further, the preparation method of the low VOC composite compatilizer comprises the following steps: and adding the copolymerized polypropylene resin, the grafting monomer and the antioxidant into a stirrer for mixing, adding the obtained mixture into a double-screw extruder, adding the initiator and the humic acid through side feeding, and performing melt extrusion at the temperature of 200-220 ℃ to obtain the low-VOC composite compatilizer.

Further, the low VOC composite compatilizer comprises the following raw materials in parts by weight: 60-75 parts of copolymerized polypropylene resin, 0.2-3.2 parts of grafting monomer, 0.3-0.5 part of antioxidant, 1-1.6 parts of initiator and 0.8-1.4 parts of humic acid.

The compatilizer is also called compatibilizer, which is a processing aid for promoting incompatible two substances to be combined together by means of intermolecular bonding force so as to obtain a stable blend. Aiming at the defects of poor impact resistance, poor weather resistance, low strength and the like of polypropylene, the strength of the plastic material can be obviously improved by adding the fibrous material into the plastic, so that the polypropylene is enhanced and modified by the common fibrous material, but polypropylene resin molecules are in a non-polar crystalline linear structure, the surface activity is low, and the fibrous material is difficult to be compatible with polar enhanced fibers and fillers, so that the fibrous material is uniformly dispersed in the polypropylene resin by adopting the compatilizer in the actual production. However, the compatilizer used in daily production contains high volatile organic compounds, and the manufactured composite material used for automobiles is undoubtedly harmful to human bodies. The invention uses the copolymerization polypropylene resin, the grafting monomer and the antioxidant, and is matched with the initiator and the humic acid selected by the invention for melt extrusion to prepare the low VOC composite compatilizer: the humic acid has excellent thermal stability and binding force, and can increase the decomposition temperature of volatile organic compounds in the material, thereby reducing the VOC content of the compatilizer at normal temperature. The composite compatilizer prepared by the invention has low VOC content, has good combination effect on polypropylene and glass fiber, has a melt index of 95-120g/10min under the conditions of 2.16kg and 190 ℃, and has a functional group content of 0.8-1.2GMA wt%.

Furthermore, the copolymerized polypropylene resin is formed by copolymerization of PP and PE blocks, so that the mechanical property and the processing flowability of PP are improved.

Furthermore, the grafting monomer is glycidyl methacrylate, and the grafting rate is 1.0-1.4%.

Further, the antioxidant is any one of antioxidant 168 or antioxidant 1010.

Further, the initiator is a compound of di-tert-butyl peroxide and cumene hydroperoxide, and the mass ratio of the initiator to the cumene hydroperoxide is (1.2-1.8): 3.

further, the inorganic filler is one or more of talcum powder, mica powder, kaolin, calcite and dolomite, and the particle size of the inorganic filler is 300-600 meshes.

Furthermore, the glass fiber is alkali-free long glass fiber, the length of the glass fiber is 5-7mm, and the diameter of the glass fiber is 6-10 μm.

Further, the adsorbent comprises, by mass, 45% -65% of a molecular sieve, 2% -5% of yttrium oxide, and the balance of diatomite.

Aiming at the problem of high VOC content in the glass fiber reinforced polypropylene composite material, the prior art usually adopts adsorbents such as activated carbon and zeolite to be mixed with preparation raw materials for melt extrusion so as to reduce the VOC content in the composite material, but the inventor finds that the activated carbon and the zeolite can adsorb VOC, but can reduce the binding effect of a conventional compatilizer such as maleic anhydride grafted polypropylene on polypropylene and glass fiber to a certain extent, so that the problem that the glass fiber is locally dispersed unevenly in the polypropylene and even floats fiber occurs. Therefore, the inventor researches to obtain a high-efficiency adsorbent: the polypropylene glass fiber compatilizer comprises 45-65% of molecular sieve, 2-5% of yttrium oxide and the balance of diatomite, and the adsorbent can effectively adsorb VOC in the material and simultaneously does not influence the combination effect of the compatilizer prepared by the invention on polypropylene and glass fiber.

The invention provides a preparation method of a low VOC glass fiber reinforced polypropylene composite material for automotive interior, which is characterized by comprising the following steps:

1) weighing the raw materials according to a formula for later use;

2) mixing and stirring 1/3 polypropylene, half of adsorbent and 1/4 low VOC composite compatilizer, and then putting the mixture into a double-screw extruder for melt extrusion and granulation to obtain master batches;

3) placing the rest 2/3 polypropylene, inorganic filler, 1/2 low VOC composite compatilizer and antioxidant into a stirrer, and stirring at a high speed of 1000r/min and 800-110 ℃ for 5-10 min;

4) and (3) putting the master batch obtained in the step 2), the mixture obtained in the step 3), the rest half of the adsorbent and the rest 1/4 low-VOC composite compatilizer into a double-screw extruder, adding glass fiber through side feeding, performing melt extrusion granulation, and cooling to obtain the low-VOC glass fiber reinforced polypropylene composite material.

According to the invention, a preparation process of melting and stirring the prefabricated master batches in a sectional component manner is selected, the adsorbent can more fully absorb VOC in the material through the prefabricated master batches, the low-VOC composite compatilizer can fully contact with all reaction raw materials through the sectional component melting and stirring, all the materials are uniformly dispersed and do not agglomerate, and the finally prepared composite material is low in VOC content and good in strength and impact resistance.

Further, the melting temperature of the twin-screw extruder in the step 2) is 160-200 ℃.

Further, the melting temperature of the twin-screw extruder in the step 4) is set as follows: the temperature of the first section is 100-.

Compared with the prior art, the invention has the beneficial effects that:

compared with the conventional glass fiber polypropylene compatilizer, the low-VOC composite compatilizer prepared by the method has the advantages of stable property, high reaction activity and lower volatile organic matter content, and can be widely applied to automotive glass fiber reinforced polypropylene composite interior trim parts. Aiming at the problem that the conventional adsorbent active carbon can destroy the combination effect of polypropylene and glass fiber, the invention also prepares a compound adsorbent which can effectively adsorb VOC in materials and does not influence the combination effect of a compatilizer. The glass fiber reinforced polypropylene composite material with low VOC content is finally prepared, the harm to human bodies is greatly weakened, and the glass fiber reinforced polypropylene composite material has a good application prospect in the field of automobile manufacturing.

Detailed Description

The present invention will be further described with reference to specific examples, but the present invention is not limited to the following examples. The process is conventional unless otherwise specified, and the starting materials are commercially available from the open literature.

Example 1

68 parts of copolymerized polypropylene resin, 1.8 parts of glycidyl methacrylate and 0.4 part of antioxidant 168 are put into a stirrer to be mixed according to parts by weight, the obtained mixture is put into a double-screw extruder, 1.3 parts of initiator (compounded by di-tert-butyl peroxide and cumene hydroperoxide according to the mass ratio of 1.6: 3) and 1.1 parts of humic acid are added through side feeding, and the mixture is melted and extruded at the temperature of 200-220 ℃ to obtain the low-VOC composite compatilizer.

Example 2

60 parts of copolymerized polypropylene resin, 2.5 parts of glycidyl methacrylate and 0.4 part of antioxidant 168 are put into a stirrer to be mixed according to the parts by weight, the obtained mixture is put into a double-screw extruder, 1.3 parts of initiator (compounded by di-tert-butyl peroxide and cumene hydroperoxide according to the mass ratio of 1.2: 3) and 1.1 parts of humic acid are added through side feeding, and the mixture is melted and extruded at the temperature of 200-220 ℃ to obtain the low-VOC composite compatilizer.

Example 3

75 parts of copolymerized polypropylene resin, 0.9 part of glycidyl methacrylate and 0.4 part of antioxidant 168 are put into a stirrer to be mixed according to the parts by weight, the obtained mixture is put into a double-screw extruder, 1.3 parts of initiator (compounded by di-tert-butyl peroxide and cumene hydroperoxide according to the mass ratio of 1.8: 3) and 1.1 parts of humic acid are added through side feeding, and the mixture is melted and extruded at the temperature of 200-220 ℃ to obtain the low-VOC composite compatilizer.

The composite compatibilizers prepared in examples 1 to 3 were subjected to performance tests, and the results are shown in Table 1.

TABLE 1

Physical property index	Inspection method	Unit of	Example 1	Example 2	Example 3
						Content of functional groups	NZG-WI-13-09	GMA wt％	1.05	0.97	0.94
Melt index	ASTM D1238[1]	g/10min	112	106	109

Note: [1]190 ℃ and 2.16kg

Example 4

A low VOC glass fiber reinforced polypropylene composite material for automotive interior:

1. weighing 78 parts of polypropylene, 30 parts of mica powder, 25 parts of alkali-free long glass fiber, 6 parts of the low-VOC composite compatilizer prepared in the embodiment 1 of the invention, 3 parts of antioxidant 168 and 2 parts of adsorbent (comprising 55% of molecular sieve, 4% of yttrium oxide and the balance of diatomite in percentage by mass);

2. mixing and stirring 1/3 polypropylene, half of adsorbent and 1/4 low VOC composite compatilizer, and then putting the mixture into a double-screw extruder for melt extrusion and granulation to obtain master batches;

3. placing the rest 2/3 polypropylene, inorganic filler, 1/2 low VOC composite compatilizer and antioxidant into a stirrer, and stirring at a high speed of 900r/min for 8min at the temperature of 95 ℃;

4. and (3) putting the master batch obtained in the step (2), the mixture obtained in the step (3), the rest half of the adsorbent and the rest 1/4 low-VOC composite compatilizer into a double-screw extruder, adding glass fibers through side feeding, performing melt extrusion granulation, and cooling to obtain the low-VOC glass fiber reinforced polypropylene composite material.

Preparation examples 5 to 8 were prepared in the same manner as in example 4 by adjusting the preparation raw materials, and the raw material settings are shown in Table 2.

TABLE 2

Note: the adsorbent comprises 48% of molecular sieve, 5% of yttrium oxide and the balance of diatomite by mass percent;

the adsorbent b comprises 64 percent of molecular sieve, 2.5 percent of yttrium oxide and the balance of diatomite according to mass percentage.

The performance of the glass fiber reinforced polypropylene composite materials prepared in examples 4 to 8 was measured, and the results are shown in Table 3.

TABLE 3

As can be seen from the performance detection data of the composite materials of examples 4-8 in Table 3, the glass fiber reinforced polypropylene composite material prepared by the preparation method disclosed by the invention is low in VOC content and good in mechanical property, and meets the relevant requirements of automobile manufacturing materials.

Comparative example 1

1. Weighing 78 parts of polypropylene, 30 parts of mica powder, 25 parts of alkali-free long glass fiber, 6 parts of the low-VOC composite compatilizer prepared in the embodiment 1 of the invention, 3 parts of antioxidant 168 and 2 parts of adsorbent (comprising 55% of molecular sieve, 4% of yttrium oxide and the balance of diatomite in percentage by mass);

2. placing polypropylene, inorganic filler, 3/4 low VOC composite compatilizer and antioxidant into a stirrer, and stirring at a high speed of 900r/min for 8min at a temperature of 95 ℃;

3. and (3) putting the mixture obtained in the step (2), the adsorbent and the residual 1/4 low-VOC composite compatilizer into a double-screw extruder, adding the glass fiber through side feeding, performing melt extrusion granulation, and cooling to obtain the glass fiber reinforced polypropylene composite material.

Comparative example 2

1. Weighing 78 parts of polypropylene, 30 parts of mica powder, 25 parts of alkali-free long glass fiber, 6 parts of maleic anhydride grafted polypropylene compatilizer, 3 parts of antioxidant 168 and 2 parts of adsorbent (comprising 55% of molecular sieve, 4% of yttrium oxide and the balance of diatomite by mass percent);

2. mixing and stirring 1/3 polypropylene, half of adsorbent and 1/4 compatilizer, and then putting the mixture into a double-screw extruder for melt extrusion and granulation to obtain master batches;

3. placing the rest 2/3 polypropylene, inorganic filler, 1/2 compatilizer and antioxidant in a stirrer, and stirring at 95 ℃ and 900r/min at a high speed for 8 min;

4. and (3) putting the master batch obtained in the step (2), the mixture obtained in the step (3), the rest half of the adsorbent and the rest 1/4 compatilizer into a double-screw extruder, adding glass fibers through side feeding, performing melt extrusion granulation, and cooling to obtain the glass fiber reinforced polypropylene composite material.

Comparative example 3

1. Weighing 78 parts of polypropylene, 30 parts of mica powder, 25 parts of alkali-free long glass fiber, 6 parts of maleic anhydride grafted polypropylene compatilizer, 3 parts of antioxidant 168 and 2 parts of adsorbent (activated carbon) according to parts by weight;

2. mixing and stirring 1/3 polypropylene, half of adsorbent and 1/4 compatilizer, and then putting the mixture into a double-screw extruder for melt extrusion and granulation to obtain master batches;

3. placing the rest 2/3 polypropylene, inorganic filler, 1/2 compatilizer and antioxidant in a stirrer, and stirring at 95 ℃ and 900r/min at a high speed for 8 min;

4. and (3) putting the master batch obtained in the step (2), the mixture obtained in the step (3), the rest half of the adsorbent and the rest 1/4 compatilizer into a double-screw extruder, adding glass fibers through side feeding, performing melt extrusion granulation, and cooling to obtain the glass fiber reinforced polypropylene composite material.

The performance of the glass fiber reinforced polypropylene composite materials prepared in comparative examples 1-3 was tested, and the results are shown in Table 4.

TABLE 4

The detection standard is that TVOC: VDA 277;

tensile strength: ISO 527;

bending strength: ISO 178;

notched impact strength: ISO 179.

Comparing the performance of the composite material prepared in example 4 with that prepared in comparative example 1, it can be seen that the total VOC content of the composite material obtained by the method of the invention is increased slightly without the use of the preformed master batch, and the strength and impact resistance are also reduced slightly, which indicates that the preformed master batch stage melting process of the invention can promote the adsorption of VOC and the dispersion of each raw material.

Comparing the composite material performance of example 4 and comparative example 2, it can be seen that the low VOC composite compatilizer prepared by the present invention is replaced by the conventional maleic anhydride grafted polypropylene compatilizer, because the VOC content of the compatilizer itself is higher, and therefore the total VOC content of the obtained composite material is obviously increased.

Comparing the performance of the composite materials prepared in comparative examples 2 and 3, it can be seen that under the precondition of using the conventional maleic anhydride grafted polypropylene compatilizer and using the conventional activated carbon as the adsorbent, the obtained composite material has a small change of the total VOC content, but the strength and the impact resistance are remarkably reduced, which is probably because the compatilizer has poor bonding effect and the material has a problem of local fiber floating.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will understand that: modifications to the embodiments of the present application or equivalent replacements of some technical features may still be made, which should all be covered by the scope of the technical solution claimed in the present application.