CN112521710A

CN112521710A - High-tensile-strength polypropylene composition

Info

Publication number: CN112521710A
Application number: CN201910884139.XA
Authority: CN
Inventors: 赵梓年; 张庆
Original assignee: Tianjin University of Science and Technology
Current assignee: Tianjin University of Science and Technology
Priority date: 2019-09-18
Filing date: 2019-09-18
Publication date: 2021-03-19

Abstract

The invention relates to the field of polymers, in particular to a polypropylene composition, a polypropylene material and application thereof. Based on the total weight of the polypropylene composition, the polypropylene composition contains 60-100 parts of block copolymerization polypropylene, 10-30 parts of high melt strength polypropylene, 0.05-2 parts of alpha crystal form nucleating agent, 0.1-0.5 part of antioxidant and 0.5-2 ml of white oil. The polypropylene material disclosed by the invention has good strength, toughness and impact resistance, and good mechanical property and processing fluidity, and the polypropylene composition and/or the polypropylene material disclosed by the invention are particularly suitable for automobile bumper products and foaming materials, so that the application range of linear polypropylene is expanded.

Description

High-tensile-strength polypropylene composition

Technical Field

The invention relates to the field of polypropylene, in particular to a high-tensile-strength polypropylene composition and application and preparation thereof.

Background

Polypropylene (PP) is a polyolefin material with excellent properties, the yield and the product quantity of which are the second place in general-purpose resins, and the product has excellent mechanical properties in general-purpose resins, and has wide application in the fields of automobile industry, household appliances, electronics, packaging, building materials, furniture and the like, however, the low strength of PP limits the wide use of PP, and therefore, the strength of PP can be effectively enhanced by a large amount of modified inorganic fillers, such as talcum powder, montmorillonite and the like.

The PP is also a PP which is paid attention to due to the fact that the PP has strong mechanical properties, namely the PP with a branched chain structure in a molecule is HMSPP, the melt strength of the HMSPP is generally 1.5-15 times of that of common PP, and the long-chain branched chain structure changes the strain softening characteristic of the common PP and improves the defects of the PP in the processing process; the HMSPP is adopted for foam molding research, and the HMSPP can effectively prevent gas loss, reduce cell combination and improve the volume expansion rate of PP foam plastics, so the HMSPP has great significance in the application of foam materials. Because the high-strength polypropylene composite material has a long-chain branch structure and obvious strain hardening behavior, namely, a melt becomes harder and stronger when being stretched or stretched, based on the characteristic, HMSPP and common PP are considered to be combined, and different proportions are adopted, so that the mechanical property of the common PP is improved.

Disclosure of Invention

The invention provides a polypropylene composition, which is characterized by comprising 60-100 parts of block copolymerization polypropylene, 10-30 parts of high melt strength polypropylene, 0.05-2 parts of alpha crystal form nucleating agent, 0.1-0.5 part of antioxidant and 0.5-2 ml of white oil by taking the total weight of the polypropylene composition as a reference.

In a second aspect, the invention provides a polypropylene material, which is obtained by melt extrusion and injection molding of the polypropylene composition of the invention.

In a third aspect, the present invention provides said polypropylene composition, particularly suitable for use in automotive bumper articles and foam applications.

After intensive research, the inventor of the invention finds that by combining the block copolymerization polypropylene, the high melt strength polypropylene, the alpha crystal form nucleating agent, the antioxidant and the white oil in a specific proportion, the polypropylene material prepared from the polypropylene composition has good mechanical properties (such as tensile strength, toughness, impact resistance and bending property) and processing fluidity, and has great industrial application prospect.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Description of the invention

Table 1 shows the mechanical and flow properties of the PP/HMSPP blend material.

Detailed Description

The following examples are given to illustrate the invention without any limiting purpose.

Mixing and stirring 60-100 parts of dried block copolymerization polypropylene, 10-30 parts of high melt strength polypropylene, 0.05-2 parts of alpha crystal form nucleating agent, 0.1-0.5 part of antioxidant and 0.5-2 ml of white oil in a 4500rpm high-speed mixer for 1 min; putting the mixed granules into a double-screw extruder for mixing together, wherein the rotating speed of a feeding screw is 25rpm, the rotating speed of a host machine screw is 60rpm, the heating temperature interval is 180-200 ℃, and vacuum drying is carried out; the extruded granules are injected and molded in an injection molding machine, the injection molding temperature interval is 180-220 ℃, and the mold temperature is 10-30 ℃; and (3) drying the injection molded sample strip in a vacuum drying oven at 100-120 ℃ for 10h, naturally cooling to room temperature, and preparing for testing.

According to the GB/T1040.2-2006 standard, a CMT4503 microcomputer control electronic universal testing machine is used for testing the tensile property of the material at the speed of 50mm/min, and the bending property of the material is tested at the speed of 2 mm/min; according to the GB/T1043 standard, a ZBC-1400-1 pendulum impact tester is used for testing the notch impact performance of the material, and at least 5 samples are selected for the tested performance and the average value is taken. The polypropylene compositions were tested for flowability using a melt flow rate meter.

The polypropylene composition prepared by the method has high mechanical property, high tensile strength, impact strength and bending property, good processing fluidity and excellent comprehensive performance, and opens up a new way for realizing the application of high-performance polypropylene.

Claims

1. The polypropylene composition is characterized by comprising 60-100 parts of block copolymerization polypropylene, 10-30 parts of high melt strength polypropylene, 0.05-2 parts of alpha crystal form nucleating agent, 0.1-0.5 part of antioxidant and 0.5-2 ml of white oil by taking the total weight of the polypropylene composition as a reference.

2. The polypropylene composition according to claim 1, wherein the block copolymer polypropylene has a melt mass flow rate of 10 to 30g/10min, preferably 15 to 30g/10min, at 230 ℃ under a 2.16kg load.

3. The polypropylene composition according to claim 1, wherein the block co-polypropylene preferably has a tensile strength of from 20MPa to 30MPa, more preferably from 25MPa to 30 MPa.

4. The polypropylene composition of claim 1, wherein the high melt strength polypropylene is formed by adjusting the ratio of weight average relative molecular mass to number average relative molecular mass (i.e., relative molecular mass width) by catalyst and electron donor technology, introducing branching structures by blending with branched oligomers and/or polymers, and creating long-chain structures within the polypropylene by reactive grafting.

5. The polypropylene composition according to claim 1, wherein the alpha crystalline nucleating agent is classified into an inorganic nucleating agent and an organic nucleating agent.

6. The polypropylene composition according to claim 5, wherein the inorganic nucleating agent mainly comprises talc, boron nitride, calcium carbonate, magnesium oxide, carbon black and the like, the particle size of the inorganic nucleating agent is generally between 0.01 and 1um, and the dosage is about 1 percent; the organic nucleating agent mainly comprises sorbitol, substituted aryl phosphate, carboxylic acid metal salt, rosin and the like, and can be combined by one or more of the sorbitol, the substituted aryl phosphate, the carboxylic acid metal salt and the rosin.

7. The polypropylene composition according to claim 1, wherein the antioxidant is a commercially available product with good oxygen resistance, low volatility and no toxicity, preferably 1010, 1076, CA, 164, DNP, DLTP, TNP, TPP, MB, 264 and the like.

8. The polypropylene composition according to claim 1, wherein the white oil is a mixture of refined liquid hydrocarbons obtained from petroleum, mainly a mixture of saturated naphthenic and paraffinic hydrocarbons, crude oil being obtained by atmospheric and vacuum fractionation, solvent extraction and dewaxing, hydrofinishing; the white oil is preferably technical white oil, cosmetic white oil, medical white oil, food white oil, etc., more preferably the white oil is technical white oil, cosmetic white oil, and still more preferably the white oil is technical white oil.

9. A polypropylene material obtained by melt extrusion and injection molding of the polypropylene composition according to any one of claims 1 to 8.

10. Polypropylene composition according to claims 1 to 9, particularly suitable for applications in automotive bumper articles and foams.