A high-strength impact-resistant modified polypropylene plastic and its application in durable toys

Abstract

The invention relates to the technical field of polypropylene and discloses a high-strength impact-resistant modified polypropylene plastic and application thereof in durable toys. The high-strength impact-resistant modified polypropylene plastic comprises 100 parts by weight of polypropylene, 10-30 parts by weight of a hyperbranched polyurethane elastomer, 2-8 parts by weight of a filler, and 0.3-0.5 parts by weight of an antioxidant. The hyperbranched polyurethane elastomer contains a long alkyl chain having good compatibility with polypropylene. Simultaneously, during a high-temperature melt extrusion process, the long alkyl chain forms a physical chain entanglement with a polypropylene molecular chain, significantly improving the compatibility between the polyurethane elastomer and the polypropylene, increasing the interfacial force between the two, and enabling the hyperbranched polyurethane elastomer to have a better toughening effect, and significantly improving tensile properties, flexural strength, and impact strength.

Description

Technical Field

[0001] The present invention relates to the technical field of polypropylene, in particular to a high-strength impact-resistant modified polypropylene plastic and application thereof in durable toys. Background Art

[0002] Polypropylene is non-toxic and odorless, transparent in appearance, light in texture, and has good insulating properties. It is widely used in the fields of toys, household appliances, building materials, medical supplies, etc. Toughening and modifying polypropylene to improve its mechanical strength are of great significance. Usually, inorganic fillers, nanomaterials, rubber elastomers, etc. are added to polypropylene to improve its mechanical properties. Polyurethane is a polymer resin material with high toughness and strength. It can be made into hyperbranched polymers, elastomeric materials, elastic fibers, etc., and has a good toughening effect on materials such as epoxy resin, polyphenylene sulfide, polyoxymethylene, and polylactic acid. Chinese patent CN116554553B discloses reacting functionalized boron nitride nanosheets, polyester diols, hexamethylene diisocyanate, and chain extenders to obtain P-BNNS modified polyurethane elastomers, which are mixed with polypropylene resins, etc. The resulting polypropylene insulating material has good insulation and flame retardant properties. However, this patent does not improve the bending, impact resistance, and other properties of the polypropylene material. Summary of the Invention

[0003] (1) Technical problems to be solved: In view of the deficiencies of the prior art, the present invention provides a modified polypropylene plastic with good mechanical strength and good impact resistance.

[0004] (2) Technical solution: A high-strength impact-resistant modified polypropylene plastic, comprising 100 parts by weight of polypropylene, 10-30 parts by weight of hyperbranched polyurethane elastomer, 2-8 parts by weight of filler, and 0.3-0.5 parts by weight of antioxidant.

[0005] The preparation method of the hyperbranched polyurethane elastomer is as follows: add dry polytetramethylene glycol, diisocyanate monomer, and dibutyltin dilaurate to a reaction vessel, introduce nitrogen, heat to 80-90°C, react for 2-3 hours, and then react with a general formula and a chain extender, wherein n is any integer from 12 to 20, poured into a mold at a temperature of 100° C., first reacted at 90 to 100° C. for 1.5 to 2 hours, then reacted at 110 to 120° C. for 4 to 5 hours, cooled and discharged to obtain a hyperbranched polyurethane elastomer.

[0006] The preparation method of high-strength impact-resistant modified polypropylene plastic is as follows: polypropylene, hyperbranched polyurethane elastomer, filler and antioxidant are mixed in a mixer, and then passed through a twin-screw extruder with a temperature of 150-185°C in sections 1-6 and a screw speed of 100-200 r / min, extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0007] Furthermore, the filler includes any one of talc, calcium carbonate, and glass beads.

[0008] Furthermore, the antioxidant includes any one of antioxidant 1010 , antioxidant 1076 , and antioxidant 168 .

[0009] Furthermore, the molar ratio of polytetramethylene ether diol, diisocyanate monomer, and chain extender is 1:(2.6-3):(1.2-1.6). The diisocyanate monomer includes any one of toluene-2,4-isocyanate and diphenylmethane-4,4'-diisocyanate.

[0010] Furthermore, the preparation method of the chain extender is:

[0011] (1) Add ethanol, terephthalaldehyde and 2-amino-1,3-propanediol in a molar ratio of 1:(2-2.2) to a reaction vessel, heat to 70-80°C, react for 18-24 hours, condense and reflux during the reaction, cool to room temperature, add sodium borohydride, react for 4-6 hours, remove ethanol by rotary evaporation, and separate and purify by silica gel column to obtain terephthalimino-1,3-propanediol. The preparation reaction formula is:

[0012]

[0013] (2) Add ethanol, 1,3-diol and 1-bromoalkane in a molar ratio of 1:(2.2-2.4) to a reaction vessel, heat to 70-80°C, react for 12-18 hours, condense and reflux during the reaction, remove ethanol by rotary evaporation, wash with water, and separate and purify by silica gel column to obtain a chain extender. The structural formula of 1-bromoalkane is Br-C n H 2n+1 , n is any integer between 12 and 20. The preparation reaction formula is:

[0014]

[0015] Furthermore, high-strength impact-resistant modified polypropylene plastics are used in durable toys.

[0016] (III) Technical Effect: A chain extender containing multiple hydroxyl and alkyl chains was prepared using inexpensive and readily available terephthalaldehyde, 2-amino-1,3-propanediol, and 1-bromoalkane as reactants. This was then copolymerized and chain extended with diisocyanate monomers and polytetramethylene ether glycol to produce a hyperbranched polyurethane elastomer. Finally, it was melt-extruded with polypropylene, calcium carbonate, and other fillers to produce a high-strength, impact-resistant modified polypropylene plastic.

[0017] The hyperbranched polyurethane elastomer of the present invention contains long alkyl chains with good compatibility with polypropylene. Simultaneously, during a high-temperature melt extrusion process, the long alkyl chains form a physical chain entanglement with polypropylene molecular chains, thereby significantly improving the compatibility between the polyurethane elastomer and polypropylene, and enhancing the interfacial interaction force between the two. This enables the hyperbranched polyurethane elastomer to have a better toughening effect, and significantly improves tensile properties, flexural strength and impact strength. DETAILED DESCRIPTION

[0018] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0019] The polypropylene used in the examples of the present invention is K7726, from Shanghai Qianfu Industrial Co., Ltd. The glass microspheres are 3M hollow glass microspheres VS5500, from Shanghai Waidian International Trading Co., Ltd. The calcium carbonate has an average particle size of 2000 mesh. The talc has an average particle size of 600 mesh.

[0020] Example 1:

[0021] (1) Add 300 mL of ethanol, 60 mmol of terephthalaldehyde, and 132 mmol of 2-amino-1,3-propanediol to a reaction vessel, heat to 80°C, react for 18 h, condense and reflux during the reaction, cool to room temperature, add 144 mmol of sodium borohydride, react for 6 h, remove ethanol by rotary evaporation, and separate and purify by silica gel column to obtain terephthalimino-1,3-propanediol.

[0022] (2) Add 250 mL of ethanol, 50 mmol of 1,3-diol, and 116 mmol of 1-bromooctadecane to a reaction vessel, heat to 70° C., and react for 18 h. During the reaction, condense and reflux, and remove ethanol by rotary evaporation. After washing with water, separate and purify on a silica gel column to obtain a chain extender.

[0023] (3) Add 50 mmol of dried polytetramethylene glycol 2000, 130 mmol of diphenylmethane-4,4'-diisocyanate, and 0.07 g of dibutyltin dilaurate to a reaction vessel, introduce nitrogen, heat to 90°C, react for 2 h, then mix with 64 mmol of a chain extender, pour into a mold at 100°C, react at 90°C for 2 h, then react at 120°C for 4 h, cool and discharge to obtain a hyperbranched polyurethane elastomer.

[0024] (4) 5 kg of polypropylene, 0.5 kg of hyperbranched polyurethane elastomer, 0.1 kg of calcium carbonate, and 18 g of antioxidant 1076 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 200 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0025] Example 2:

[0026] (1) Add 300 mL of ethanol, 60 mmol of terephthalaldehyde, and 120 mmol of 2-amino-1,3-propanediol to a reaction vessel, heat to 70°C, react for 24 h, condense and reflux during the reaction, cool to room temperature, add 156 mmol of sodium borohydride, react for 4 h, remove ethanol by rotary evaporation, and separate and purify by silica gel column to obtain terephthalimino-1,3-propanediol.

[0027] (2) Add 300 mL of ethanol, 50 mmol of 1,3-diol, and 110 mmol of 1-bromoeicosane to a reaction vessel, heat to 80° C., and react for 12 h. During the reaction, condense and reflux, remove ethanol by rotary evaporation, wash with water, and purify by silica gel column separation to obtain a chain extender.

[0028] (3) Add 50 mmol of dried polytetramethylene glycol 2000, 150 mmol of toluene-2,4-isocyanate, and 0.08 g of dibutyltin dilaurate into a reaction vessel, introduce nitrogen, heat to 85°C, react for 3 h, then mix with 80 mmol of a chain extender, pour into a mold at 100°C, react at 100°C for 1.5 h, then react at 120°C for 4 h, cool and discharge to obtain a hyperbranched polyurethane elastomer.

[0029] (4) 5 kg of polypropylene, 0.8 kg of hyperbranched polyurethane elastomer, 0.22 kg of talc, and 25 g of antioxidant 168 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 200 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0030] Example 3:

[0031] (1) According to the method of Example 1, 1,3-diol was prepared.

[0032] (2) Add 250 mL of ethanol, 50 mmol of 1,3-diol, and 120 mmol of 1-bromododecane to a reaction vessel, heat to 80° C., and react for 12 h. During the reaction, condense and reflux, remove ethanol by rotary evaporation, wash with water, and purify by silica gel column separation to obtain a chain extender.

[0033] (3) Add 50 mmol of dried polytetramethylene glycol 2000, 140 mmol of diphenylmethane-4,4'-diisocyanate, and 0.07 g of dibutyltin dilaurate to a reaction vessel, introduce nitrogen, heat to 90°C, react for 2 h, then mix with 66 mmol of a chain extender, pour into a mold at 100°C, react at 90°C for 2 h, then react at 120°C for 4 h, cool and discharge to obtain a hyperbranched polyurethane elastomer.

[0034] (4) 5 kg of polypropylene, 1.2 kg of hyperbranched polyurethane elastomer, 0.4 kg of glass microspheres, and 15 g of antioxidant 1010 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 200 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0035] Example 4:

[0036] (1) According to the method of Example 1, 1,3-diol was prepared.

[0037] (2) Add 350 mL of ethanol, 50 mmol of 1,3-diol, and 120 mmol of 1-bromotetradecane to a reaction vessel, heat to 75° C., and react for 18 h. During the reaction, condense and reflux, and remove ethanol by rotary evaporation. After washing with water, separate and purify on a silica gel column to obtain a chain extender.

[0038] (3) Add 50 mmol of dried polytetramethylene glycol 2000, 150 mmol of toluene-2,4-isocyanate, and 0.07 g of dibutyltin dilaurate into a reaction vessel, introduce nitrogen, heat to 80°C, react for 3 h, then mix with 80 mmol of a chain extender, pour into a mold at 100°C, react at 100°C for 1.5 h, then react at 110°C for 5 h, cool and discharge to obtain a hyperbranched polyurethane elastomer.

[0039] (4) 5 kg of polypropylene, 1.5 kg of hyperbranched polyurethane elastomer, 0.1 kg of calcium carbonate, and 18 g of antioxidant 1076 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 100 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0040] Comparative Example 1:

[0041] (1) 5 kg of polypropylene, 0.1 kg of calcium carbonate, and 18 g of antioxidant 1076 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 200 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0042] Comparative Example 2:

[0043] (1) Add 50 mmol of dried polytetramethylene glycol 2000, 130 mmol of diphenylmethane-4,4'-diisocyanate, and 0.07 g of dibutyltin dilaurate into a reaction vessel, introduce nitrogen, heat to 90°C, react for 2 h, then mix with 64 mmol of stearyl diethanolamine, pour into a mold at a temperature of 100°C, react at 90°C for 2 h, then react at 120°C for 4 h, cool and discharge to obtain a polyurethane elastomer.

[0044] (2) 5 kg of polypropylene, 0.5 kg of polyurethane elastomer, 0.1 kg of calcium carbonate, and 18 g of antioxidant 1076 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 200 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0045] Comparative Example 3:

[0046] (1) According to the method of Example 1, 1,3-diol was prepared.

[0047] (2) Add 250 mL of ethanol, 50 mmol of 1,3-diol, and 116 mmol of 1-bromopropane to a reaction vessel, heat to 70° C., and react for 18 h. During the reaction, condense and reflux, and remove ethanol by rotary evaporation. After washing with water, separate and purify on a silica gel column to obtain a chain extender.

[0048] (3) Add 50 mmol of dried polytetramethylene glycol 2000, 130 mmol of diphenylmethane-4,4'-diisocyanate, and 0.07 g of dibutyltin dilaurate to a reaction vessel, introduce nitrogen, heat to 90°C, react for 2 h, then mix with 64 mmol of a chain extender, pour into a mold at 100°C, react at 90°C for 2 h, then react at 120°C for 4 h, cool and discharge to obtain a hyperbranched polyurethane elastomer.

[0049] (4) 5 kg of polypropylene, 0.5 kg of hyperbranched polyurethane elastomer, 0.1 kg of calcium carbonate, and 18 g of antioxidant 1076 were mixed in a mixer, and then passed through a twin-screw extruder with the temperatures of sections 1-6 being 150°C, 160°C, 175°C, 185°C, 185°C, and 180°C, and the screw speed being 200 r / min, and extruded and pelletized to obtain high-strength impact-resistant modified polypropylene plastic.

[0050] Modified polypropylene was injection molded into test strips. Tensile properties were tested according to GB / T 1040.1-2018. Flexural properties were tested according to GB / T 9341-2008. Impact properties were tested according to GB / T 1043.1-2008.

[0051] Table 1 Modified polypropylene plastic performance test

[0052]

[0053] After testing, the tensile properties, flexural strength, and impact strength of the polypropylene plastic in Comparative Example 1 were relatively low. Examples 1-4 added hyperbranched polyurethane elastomers with excellent mechanical properties to toughen polypropylene. The hyperbranched polyurethane elastomers contain long alkyl chains that are compatible with polypropylene. During high-temperature melt extrusion, the long alkyl chains form a physical chain entanglement with the polypropylene molecular chains, significantly improving the compatibility between the polyurethane elastomer and polypropylene and increasing the interfacial interaction force between the two. This gives the hyperbranched polyurethane elastomers better toughening properties, significantly improving tensile properties, flexural strength, and impact strength.

[0054] Comparative Example 2 uses stearyl diethanolamine as a chain extender, which contains a long alkyl chain. The resulting polyurethane elastomer has high compatibility and interfacial force with polypropylene, and has a good toughening effect. The tensile properties, flexural strength, and impact strength of the polypropylene are higher than those of Comparative Example 1. However, stearyl diethanolamine contains only two hydroxyl polymerization chain extension sites, and the resulting polyurethane elastomer does not have a hyperbranched structure, resulting in poor mechanical properties and limited toughening effect on polypropylene. The tensile properties, impact strength, and other properties are lower than those of the various examples.

[0055] In Comparative Example 3, 1,3-diol and 1-bromopropane are used as reactants, and the resulting chain extender does not contain long alkyl chains, resulting in poor compatibility and interfacial force between the hyperbranched polyurethane elastomer and polypropylene, general toughening effect, and lower tensile properties, impact strength and other properties of polypropylene than those of the embodiments.

Claims

1. A high-strength impact-resistant modified polypropylene plastic, characterized in that: The invention comprises 100 parts by weight of polypropylene, 10-30 parts by weight of hyperbranched polyurethane elastomer, 2-8 parts by weight of filler, and 0.3-0.5 parts by weight of antioxidant; The preparation method of the hyperbranched polyurethane elastomer is as follows: adding dry polytetramethylene glycol, diisocyanate monomer, and dibutyltin dilaurate into a reaction container, introducing nitrogen, heating to 80-90° C., reacting for 2-3 hours, and then reacting with a general structural formula The mixture is mixed with a chain extender, poured into a mold, reacted at 90-100°C for 1.5-2h, then reacted at 110-120°C for 4-5h, cooled and discharged to obtain a hyperbranched polyurethane elastomer; Said general structural formula wherein n is any integer from 12 to 20; The molar ratio of the polytetramethylene ether diol, diisocyanate monomer and chain extender is 1:(2.6-3):(1.2-1.6).

2. The high-strength impact-resistant modified polypropylene plastic according to claim 1, characterized in that: The filler includes any one of talc, calcium carbonate, and glass microbeads.

3. The high-strength impact-resistant modified polypropylene plastic according to claim 1, characterized in that: The antioxidant includes any one of antioxidant 1010, antioxidant 1076, and antioxidant 168.

4. The high-strength impact-resistant modified polypropylene plastic according to claim 1, characterized in that: The diisocyanate monomer includes any one of toluene-2,4-isocyanate and diphenylmethane-4,4'-diisocyanate.

5. The high-strength impact-resistant modified polypropylene plastic according to claim 1, characterized in that: The preparation method of the chain extender is: (1) adding ethanol, terephthalaldehyde and 2-amino-1,3-propanediol in a molar ratio of 1:(2-2.2) to a reaction vessel, heating to 70-80° C., reacting for 18-24 hours, condensing and refluxing during the reaction, cooling to room temperature, adding sodium borohydride, reacting for 4-6 hours, rotary evaporation, and separation and purification on a silica gel column to obtain terephthalimino-1,3-propanediol; (2) Add ethanol, 1,3-diol and 1-bromoalkane in a molar ratio of 1:(2.2-2.4) to a reaction vessel, heat to 70-80°C, react for 12-18 hours, condense and reflux during the reaction, rotary evaporate, wash, and separate and purify on a silica gel column to obtain a chain extender.

6. The high-strength impact-resistant modified polypropylene plastic according to claim 5, characterized in that: The structural formula of the 1-bromoalkane is Br-C n H 2n+1 , n is any integer between 12 and 20.

7. A method for preparing the high-strength impact-resistant modified polypropylene plastic according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: mixing polypropylene, hyperbranched polyurethane elastomer, filler and antioxidant in a mixer, and then extruding and pelletizing the mixture through a twin-screw extruder with the temperature of sections 1-6 being 150-185°C and the screw speed being 100-200 r / min to obtain high-strength impact-resistant modified polypropylene plastic.

8. Use of the high-strength impact-resistant modified polypropylene plastic obtained by the preparation method according to claim 7 in durable toys.

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