Composition, mixed plastic dynamic crosslinking material and preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a composition, a mixed plastic dynamic crosslinking material and a preparation method and application thereof. The composition comprises the following components in parts by mass: 100 parts of a heterochain polymer; 5 parts by mass to 2000 parts by mass of polyolefin; 1 part by mass to 200 parts by mass of a polyhydroxy compound; 1 to 200 parts by mass of a grafting agent; and 0.25 to 40 parts by mass of a radical initiator. The mixed plastic dynamic cross-linking material prepared by utilizing the composition through a chain scission-grafting-dynamic cross-linking multi-step synergistic strategy has excellent thermal, mechanical and reprocessing properties.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to a composition, a mixed plastic dynamic crosslinking material and a preparation method and application thereof. BACKGROUND

[0002] Due to the fact that many types of plastics are non-biodegradable and are mostly improperly discarded, plastic waste is proliferating in landfills, waterways and oceans. Between 1950 and 2015, an estimated 8.3 billion tons of plastic was produced, but only about 9% was recycled, 12% was used for energy generation incineration, and the remaining 6.3 billion tons has largely accumulated in the environment. Current projections are that by 2030, approximately 53 million tons of plastic waste will be disposed of in the environment each year. In addition to polluting the environment, greenhouse gas emissions generated by plastic production in the life cycle are projected to grow from 170 million tons of carbon dioxide equivalent in 2015 to 650 million tons in 2050, about 15% of global carbon emissions.

[0003] Mixed plastics are multi-component materials mixed by two or more than two plastics with different chemical structures, and polyolefins and heterochain polymers (such as polyesters) are the two common polymers in mixed plastics. Due to the poor compatibility of polyolefins and polyesters and other components in mixed plastics, they are not easy to mix and melt during melt reprocessing, and the interfacial adhesion is poor, so direct recycling of mixed plastics containing polyolefins and polyesters and other components by melt reprocessing will result in poor product performance. At present, some existing technologies propose to add a compatibilizer to the recycled mixed plastics, and the compatibilizer is generally an amphiphilic block polymer, such as a functionalized polyolefin containing a hydroxyl functional group. However, this method has poor compatibilization effect, and the synthesis of the amphiphilic block polymer is complex and tedious to operate, and it has specificity and poor universality. Therefore, to realize the upgrading and recycling of mixed plastics, it is necessary to improve the compatibility of the mixture and solve the problem of phase separation caused by the difference in molecular structure, so as to promote the recycling of waste mixed plastics. SUMMARY

[0004] To solve all or part of the above technical problems, the present application provides the following technical solutions: The first aspect of the present application provides a composition for preparing a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material, comprising, by mass fraction: a heterochain polymer, the heterochain polymer being a polymer containing any one or more of oxygen, nitrogen, sulfur, silicon and phosphorus in the main chain: 100 parts by mass; a polyolefin: 5 parts by mass to 2000 parts by mass; a polyhydroxy compound: 1 part by mass to 200 parts by mass; a grafting agent: 1 part by mass to 200 parts by mass; Radical initiator: 0.25 parts by mass to 40 parts by mass.

[0005] In some embodiments, the heterochain polymer includes one or more of a combination of polyester, polyurethane, polycarbonate, and polyoxymethylene.

[0006] Further, the polyester includes one or more of a combination of polybutylene adipate terephthalate, polylactic acid, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene-2,6-naphthalate, ethylene glycol-modified PCT copolyester, cis / trans-1,4-cyclohexanedimethylene-modified PET copolyester, polybutylene succinate, polyethylene-2,5-furandicarboxylate, polytrimethylene-2,5-furandicarboxylate, and poly-1,4-butanediol-2,5-furandicarboxylate, but is not limited thereto.

[0007] In some embodiments, the polyolefin includes one or more of a combination of polyethylene, polypropylene, polystyrene, polybutylene, ethylene-propylene copolymer, ethylene-acrylic acid copolymer, polyisobutylene, poly-1-butene, poly-1-pentene, poly-4-methyl-1-pentene, ethylene-1,2-octene copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethylene vinyl alcohol resin, acrylonitrile-butadiene-styrene copolymer, and acrylonitrile-styrene-acrylate rubber copolymer, but is not limited thereto.

[0008] In some embodiments, the polyhydroxyl compound contains two or more hydroxyl groups, and the boiling point B of the polyhydroxyl compound satisfies B≥A+10°C, where A is the higher one of the melting point of the heterochain polymer and the melting point of the polyolefin.

[0009] Further, the polyhydroxyl compound includes one or more of a combination of dipentaerythritol, pentaerythritol, diethylene glycol, triethylene glycol, sorbitol, erythritol, glucose, maltose, sucrose, glycerol, diglycerol, xylitol, trimethylol ethane, trimethylol propane, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, methylpropanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, dipropylene glycol, triethanolamine, 2-di(2-hydroxyethyl)amino-2-hydroxymethyl-1,3-propanediol, and bis(2-hydroxyethyl)amino(trimethylol)methane, but is not limited thereto.

[0010] In some embodiments, the grafting agent includes a compound containing a carbon-carbon double bond and an anhydride group.

[0011] Further, the grafting agent includes one or a combination of maleic anhydride, itaconic anhydride, citraconic anhydride, nadic anhydride, but is not limited thereto.

[0012] In some embodiments, the radical initiator includes a peroxide.

[0013] Further, the radical initiator includes at least one of benzoyl peroxide, dicumyl peroxide, lauryl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, tert-butyl peroxybenzoate, 2,2-di(tert-butylperoxy)butane, tert-butyl cumyl peroxide, diisopropyl peroxydicarbonate, diisobutyl peroxydicarbonate, tert-butyl peroxyneopentanoate, tert-amyl peroxyneopentanoate, dicyclohexyl peroxydicarbonate, tert-butyl peroxyisooctanoate, di(3,5,5-trimethylhexanoyl) peroxide, tert-butyl peroxylsopropyl carbonate, dibenzoyl tert-butyl peroxide, tert-butyl peroxyacetate, di-tert-butyl peroxide, but is not limited thereto.

[0014] The second aspect of the present application provides a composition for preparing a mixed plastic dynamic crosslinking material, comprising, in parts by mass: a recycled waste mixed plastic, the recycled waste mixed plastic being used to provide 100 parts by mass of a heterochain polymer and 5 parts by mass to 2000 parts by mass of a polyolefin, wherein the heterochain polymer is a polymer containing any one or more of oxygen, nitrogen, sulfur, silicon, phosphorus as a heteroatom in a main chain; a polyhydroxy compound: 1 part by mass to 200 parts by mass; a grafting agent: 1 part by mass to 200 parts by mass; a radical initiator: 0.25 parts by mass to 40 parts by mass.

[0015] Further features or specific choices of the heterochain polymer, the polyolefin, the polyhydroxy compound, the grafting agent and the radical initiator in the composition of the second aspect of the present application are the same as those specifically set forth in the first aspect of the present application, and will not be repeated here.

[0016] The third aspect of the present application provides a preparation method of a mixed plastic dynamic crosslinking material, comprising: melt-extruding the composition for preparing a mixed plastic dynamic crosslinking material according to any one of the technical solutions described above in a protective atmosphere, wherein the composition undergoes chain scission reaction, grafting reaction and dynamic crosslinking reaction during the melt-extruding process, and then is cooled and granulated to obtain a mixed plastic dynamic crosslinking material.

[0017] The composition provided by the application can occur chain scission reaction, grafting reaction and dynamic crosslinking reaction in the melt extrusion process, and the prepared heterochain polymer / polyolefin mixed plastic dynamic crosslinking material has excellent thermal properties, mechanical properties and reprocessing properties.

[0018] Specifically, in the chain scission stage, the polyhydroxy compound in the composition acts as a chain scission agent, and dynamic ester exchange occurs between the hydroxyl group of the polyhydroxy compound and the ester bond of the heterochain polymer (such as the polyester main chain), thereby breaking the heterochain polymer main chain, reducing the molecular weight, and increasing the proportion of hydroxyl functional groups in the heterochain polymer fragment; In the grafting stage, the grafting agent grafts the polyolefin and part of the heterochain polymer fragment (containing a free radical initiation site), effectively increasing the polarity of the polyolefin molecular chain, thereby improving the compatibility between the heterochain polymer and the polyolefin, and promoting the crosslinking reaction between the heterochain polymer fragment and the grafting agent in the subsequent stage; In the crosslinking stage, due to the breaking of the heterochain polymer main chain and the reduction of the molecular chain, more carboxyl groups are exposed, which promotes the reaction between the active hydrogen on the carboxyl group of the heterochain polymer and the anhydride group of the grafting agent to form a dynamic ester bond, thereby facilitating the construction of a perfect dynamic crosslinking polymer network, increasing the molecular weight of the heterochain polymer / polyolefin dynamic covalent crosslinking network, and further improving its thermal properties and mechanical properties. In addition, the ortho carboxyl group formed by the reaction of anhydride and hydroxyl group (part of which is derived from polyhydroxy compound, and part of which is derived from new hydroxyl group generated after the chain scission reaction of heterochain polymer such as polyester) can promote the occurrence of ester exchange reaction by utilizing its own structure and the synergistic effect of ester bond, which is beneficial to improve the dynamic properties of the formed crosslinking polymer network, thereby improving the reprocessing performance of the heterochain polymer / polyolefin dynamic covalent crosslinking network. The high degree of dynamic crosslinking of the heterochain polymer / polyolefin dynamic covalent crosslinking network of the application can be reprocessed by screw extrusion and hot pressing, and the mechanical properties after reprocessing are still excellent.

[0019] In some embodiments, the temperature of the melt extrusion is 30°C to 280°C.

[0020] The protective atmosphere described in the application is, for example, an inert atmosphere commonly used in the art, such as nitrogen.

[0021] In some embodiments, the preparation method first dries the heterochain polymer, polyolefin, polyhydroxy compound, grafting agent and free radical initiator to a moisture content of 0.3% or less, and then performs the melt extrusion. The drying method can include vacuum drying at 50-150°C for 5-24h.

[0022] The fourth aspect of the application provides a recycling and processing method for mixed plastics, comprising: The waste mixed plastic to be recycled contains 100 parts by mass of a heterochain polymer and 5 to 2000 parts by mass of a polyolefin, wherein the heterochain polymer is a polymer having one or more heteroatoms selected from the group consisting of oxygen, nitrogen, sulfur, silicon, and phosphorus in a main chain; The waste mixed plastic is mixed with 1 to 200 parts by mass of a polyol, 1 to 200 parts by mass of a grafting agent, and 0.25 to 40 parts by mass of a radical initiator to obtain a mixture; The mixture is subjected to melt extrusion in a protective atmosphere, during which chain scission, grafting, and dynamic crosslinking reactions occur, and then cooled and granulated to obtain a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material.

[0023] In some embodiments, the temperature of the melt extrusion is 30 to 280°C.

[0024] In some embodiments, the preparation method first dries the recycled waste mixed plastic, the polyol, the grafting agent, and the radical initiator to a moisture content of 0.3% or less, and then performs the melt extrusion. The drying method can include vacuum drying at 50 to 150°C for 5 to 24 hours.

[0025] The further features or specific choices of the heterochain polymer, the polyolefin, the polyol, the grafting agent, and the radical initiator in the "mixed plastic recycling method" of the fourth aspect of the present application are the same as those specifically set forth in the first aspect of the present application "composition for preparing a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material", and will not be described here.

[0026] The fifth aspect of the present application provides a mixed plastic dynamic crosslinking material prepared by any one of the preparation methods of the plastic dynamic crosslinking material, or prepared by any one of the mixed plastic recycling methods.

[0027] The sixth aspect of the present application provides a plastic product comprising the mixed plastic dynamic crosslinking material of any one of the technical solutions. For example, it can be a plate, a film, a block, or the like formed from the mixed plastic dynamic crosslinking material of the present application.

[0028] Compared with the prior art, the present application has at least the following beneficial effects: (1) The present application prepares a mixed plastic dynamic crosslinking material based on a heterochain polymer / polyolefin dynamic covalent crosslinking network through a multi-step synergistic strategy of "chain scission-grafting-dynamic crosslinking", which has excellent thermal, mechanical, and reprocessing properties; at the same time, the raw materials are easy to obtain, the preparation method is simple and efficient, and it is convenient for industrial production.

[0029] (2) The application provides a recycling processing method of mixed plastics, which comprises the following steps: recycling mixed plastics containing heterochain polymers (such as polyester) and polyolefins, and introducing a polyhydroxy compound, a grafting agent and a free radical initiator, so that the obtained mixture is subjected to chain breaking, grafting and dynamic crosslinking reactions, thereby improving the compatibility between the heterochain polymers and the polyolefins in the plastics, and endowing the recycled plastics with excellent thermal and mechanical properties, and solving the problems of poor compatibility of the heterochain polymers and the polyolefins in the mixed plastics and the lack of mechanical properties of the recycled plastics. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0031] Figure 1 is a reaction principle diagram of the preparation method of the heterochain polymer / polyolefin mixed plastic dynamic crosslinking material provided in the embodiments; Figure 2 is a creep curve of the plate based on the heterochain polymer / polyolefin mixed plastic dynamic crosslinking material prepared in the embodiment 1 and the comparative example 10 under the condition of 80 DEG C; Figure 3 is a tensile curve of the plate based on the heterochain polymer / polyolefin mixed plastic dynamic crosslinking material prepared in the embodiment 1 and the tensile curve after the recycled 3 times; Figure 4 is an electron microscope graph of the mixture in the embodiment 1 in the molten state (left graph), and an electron microscope graph of the plate prepared therefrom (right graph). DETAILED DESCRIPTION

[0032] The present application will be more fully understood from the following detailed description taken in connection with the accompanying drawings. Detailed embodiments of the present application are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the present application, which can be embodied in various forms. Therefore, specific functional details disclosed herein are not to be interpreted as limiting, but only as a representative basis for teaching one skilled in the art to employ the present application in virtually any appropriate detailed embodiment. It will be apparent to those skilled in the art that numerous modifications, both as to the equipment and methods described, can be made without departing from the scope of the present application.

[0033] In addition, unless specifically stated otherwise, the various raw materials used in the following examples can be obtained from market or the like, and the various production and testing equipment used are all known equipment in the art, and the testing methods used are also known methods in the art.

[0034] In the following examples and comparative examples, the "parts" of the components mentioned are all mass parts, unless otherwise specified.

[0035] Example 1 The present example provides a composition, and a method for preparing a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material based on the composition, which specifically comprises: (1) PET (CZ-318) particles, PP (T30S), dipentaerythritol, maleic anhydride and dicumyl peroxide were respectively placed in a vacuum oven and dried to a water content of 0.3% or less; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (as a polyolefin), 4 parts of dipentaerythritol (a polyhydroxy compound), 6 parts of maleic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) were uniformly mixed to obtain a mixture; (3) The mixture was added to a twin-screw extruder through a hopper, and melt extruded under nitrogen protection. The working parameters of the twin-screw extruder were as follows: the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30℃, 240℃, 250℃ and 260℃ respectively, and the cycle extrusion time was 5 min; then the product was cooled and granulated to obtain a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material, which was then pressed into a plate in a flat vulcanization instrument.

[0036] Figure 1 is the reaction principle diagram of the preparation method of the heterochain polymer / polyolefin mixed plastic dynamic crosslinking material provided by the present example. Taking Example 1 as an example, the chain breaker dipentaerythritol is added to break the PET polymer molecular chain through ester exchange reaction, and the polyolefin / polyester is grafted to increase the reaction sites; at the same time, the anhydride of the polyolefin / polyester graft reacts with the active hydroxyl group to form a high molecular crosslinking network, thereby improving the thermal, mechanical and reprocessing properties of the mixed plastic dynamic crosslinking material plate based on the dynamic covalent crosslinking network.

[0037] Example 2 Example 2 is basically the same as Example 1, except that 4 parts of maleic anhydride are used as the grafting agent instead of 6 parts of maleic anhydride, and the rest is the same as Example 1, which will not be repeated here.

[0038] Example 3 Example 3 is basically the same as Example 1, except that 4 parts of 2-di(2-hydroxyethyl)amino-2-hydroxymethyl-1,3-propanediol are used instead of 4 parts of dipentaerythritol, and the rest is the same as Example 1, which will not be repeated here.

[0039] Example 4 Example 4 is substantially the same as Example 3, except that 100 parts of PP (T30S) in Example 3 is replaced by 70 parts of PE (EX5) powder and 30 parts of PP, and the rest is the same as Example 1, which is not repeated here.

[0040] Example 5 Example 5 is substantially the same as Example 1, except that 4 parts of dipentaerythritol is replaced by 4 parts of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and the rest is the same as Example 1, which is not repeated here.

[0041] Example 6 The present embodiment provides a composition, and a method for preparing a heterochain polymer / polyolefin mixed plastic dynamic cross-linking material based on the composition, which specifically comprises: (1) PET (CZ-318) particles, PE (EX5), dipentaerythritol, maleic anhydride and dicumyl peroxide are respectively placed in a vacuum oven to dry to a water content of 0.3% or less; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PE (EX5) (as a polyolefin), 4 parts of dipentaerythritol (a polyhydroxy compound), 6 parts of maleic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are mixed to obtain a mixture; (3) The mixture is added to a double-screw extruder through a hopper, and melt extruded under nitrogen protection, with the working parameters of the double-screw extruder being: a feeding rotation speed of 15 rpm, a screw rotation speed of 30 rpm, four temperature zones being 30℃, 240℃, 250℃ and 260℃ respectively, and a cycle extrusion time of 5 min; then cooled and granulated to obtain a heterochain polymer / polyolefin mixed plastic dynamic cross-linking material, and pressed into a plate material in a flat plate vulcanizer.

[0042] Example 7 Example 7 is substantially the same as Example 2, except that maleic anhydride is replaced by itaconic anhydride, and the rest is the same as Example 2, which is not repeated here.

[0043] Example 8 Example 8 is substantially the same as Example 1, except that polyester PET (CZ-318) is replaced by 100 parts of PC-6600 particles, and the four temperature zones during melt extrusion are 30℃, 220℃, 230℃ and 240℃ respectively, and the rest is the same as Example 1, which is not repeated here.

[0044] Example 9 Example 9 is substantially the same as Example 8, except that dipentaerythritol is replaced by glycerol, maleic anhydride is replaced by itaconic anhydride, and the rest is the same as Example 8, which is not repeated here.

[0045] Example 10 Example 10 is substantially the same as Example 8, except that 6 parts of maleic anhydride is replaced by 4 parts of maleic anhydride, dipentaerythritol is replaced by glycerol, and dicumyl peroxide is replaced by benzoyl peroxide, and the rest is the same as Example 8, which is not repeated here.

[0046] Example 11 Example 11 is substantially the same as Example 1, except that PET (CZ-318) particles are replaced by 100 parts of polyurethane (1170AU) particles; during melt extrusion, the four temperature zones are 30℃, 180℃, 190℃, and 200℃, respectively, and the rest is the same as Example 1, which is not repeated here.

[0047] Example 12 Example 12 is substantially the same as Example 11, except that PP (T30S) particles are replaced by PS particles, and the rest is the same as Example 11, which is not repeated here.

[0048] Example 13 Example 13 is substantially the same as Example 11, except that dicumyl peroxide is replaced by a mixture of dicumyl peroxide / di-tert-butyl peroxide, and the rest is the same as Example 11, which is not repeated here.

[0049] Example 14 The present embodiment provides a composition and a method for preparing a heterochain polymer / polyolefin hybrid plastic dynamic cross-linking material based on the composition, which specifically comprises: (1) PET (CZ-318) particles, PP (T30S), sorbitol, maleic anhydride, and dicumyl peroxide are respectively placed in a vacuum oven and dried to a water content of less than 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 6 parts of maleic anhydride (as a grafting agent), and 1 part of dicumyl peroxide (as a free radical initiator) are mixed to obtain a mixture; (3) The mixture is added into a twin-screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the cycle extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, and a plate is pressed in a flat vulcanization instrument.

[0050] Example 15 The present example provides a composition and a method for preparing a dynamically crosslinked material of a heterochain polymer / polyolefin mixed plastic based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PP (T30S), sorbitol, itaconic anhydride and dicumyl peroxide are respectively placed into a vacuum oven and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 6 parts of itaconic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixture; (3) The mixture is added into a twin-screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the cycle extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, and a plate is pressed in a flat vulcanization instrument.

[0051] Example 16 The present example provides a composition and a method for preparing a dynamically crosslinked material of a heterochain polymer / polyolefin mixed plastic based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PP (T30S), pentaerythritol, itaconic anhydride and dicumyl peroxide are respectively placed into a vacuum oven and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 6 parts of pentaerythritol (a polyhydroxy compound), 6 parts of itaconic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixture; (3) The mixed material is added into a double screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the double screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the cycle extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, and a plate is pressed in a flat vulcanization instrument.

[0052] Example 17 The present example provides a composition and a method for preparing a dynamically crosslinked material of a heterochain polymer / polyolefin mixed plastic based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PP (T30S), 2,2,4,4-tetramethyl-1,3-cyclobutanediol, itaconic anhydride and dicumyl peroxide are respectively placed into a vacuum oven for drying until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 12 parts of 2,2,4,4-tetramethyl-1,3-cyclobutanediol (a polyhydroxy compound), 6 parts of itaconic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixed material; (3) The mixed material is added into a double screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the double screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the cycle extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, and a plate is pressed in a flat vulcanization instrument.

[0053] Example 18 Example 18 is basically the same as Example 1, except that the PET (CZ-318) particles are replaced by poly(2,5-furandicarboxylate-1,3-propylene glycol), and the rest is the same as Example 1, which will not be repeated here.

[0054] Example 19 Example 19 is basically the same as Example 1, except that the PET (CZ-318) particles are replaced by PLA (L105) particles; during melt extrusion, the temperatures of the four temperature zones are 30°C, 175°C, 185°C and 195°C respectively, and the rest is the same as Example 1, which will not be repeated here.

[0055] Example 20 Example 20 is substantially the same as Example 1, except that the PET (CZ-318) particles are replaced by poly-1,4-cyclohexylenedimethylene terephthalate; the four temperature zones during melt extrusion are 30℃, 290℃, 300℃, 310℃, respectively, and the rest is the same as Example 1, which is not repeated here.

[0056] Example 21 Example 21 is substantially the same as Example 1, except that 100 parts of PET (CZ-318) particles are replaced by 70 parts of PBAT (TH801T) particles and 30 parts of PLA (L105) particles; the four temperature zones during melt extrusion are 30℃, 175℃, 185℃, 195℃, respectively, and the rest is the same as Example 1, which is not repeated here.

[0057] Example 22 Example 22 is substantially the same as Example 1, except that the PET (CZ-318) particles are replaced by polyformaldehyde (M90-44); the four temperature zones during melt extrusion are 30℃, 220℃, 230℃, 240℃, respectively, and the rest is the same as Example 1, which is not repeated here.

[0058] Example 23 Example 23 is substantially the same as Example 1, except that 100 parts of polyolefin PP (T30S) are replaced by 100 parts of polyolefin EVA (7350M), and the rest is the same as Example 1, which is not repeated here.

[0059] Example 24 The present embodiment provides a composition and a method for preparing a heterochain polymer / polyolefin mixed plastic dynamic cross-linking material based on the composition, which specifically comprises: (1) PET (CZ-318) particles, PP (T30S), sorbitol, pyromellitic dianhydride, and dicumyl peroxide are respectively placed in a vacuum oven and dried to a water content of 0.3% or less; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 4 parts of pyromellitic dianhydride (as a grafting agent), and 1 part of dicumyl peroxide (as a free radical initiator) are mixed to obtain a mixture; (3) The mixed material is added into the twin-screw extruder through the hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the circulation extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the heterochain polymer / polyolefin mixed plastic dynamic crosslinking material, which is pressed into a plate in a flat vulcanization instrument.

[0060] Example 25 The embodiment provides a composition and a method for preparing a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PP (T30S), sorbitol, citraconic anhydride and dicumyl peroxide are respectively placed into a vacuum oven and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 4 parts of citraconic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixed material; (3) The mixed material is added into the twin-screw extruder through the hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the circulation extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the heterochain polymer / polyolefin mixed plastic dynamic crosslinking material, which is pressed into a plate in a flat vulcanization instrument.

[0061] Example 26 The embodiment provides a composition and a method for preparing a heterochain polymer / polyolefin mixed plastic dynamic crosslinking material based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PP (T30S), sorbitol, nadic anhydride and dicumyl peroxide are respectively placed into a vacuum oven and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PP (T30S) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 6 parts of nadic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixed material; (3) The mixture is added into a twin-screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the extrusion is recycled for 5 minutes. Then, the product is cooled and granulated to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, which is pressed into a plate in a flat vulcanization instrument.

[0062] Example 27 The present example provides a composition and a method for preparing a dynamically crosslinked material of a heterochain polymer / polyolefin mixed plastic based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PE (EX5), sorbitol, nadic anhydride and dicumyl peroxide are respectively placed into a vacuum oven and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PE (EX5) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 6 parts of nadic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixture; (3) The mixture is added into a twin-screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the extrusion is recycled for 5 minutes. Then, the product is cooled and granulated to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, which is pressed into a plate in a flat vulcanization instrument.

[0063] Example 28 The present example provides a composition and a method for preparing a dynamically crosslinked material of a heterochain polymer / polyolefin mixed plastic based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PE (EX5), sorbitol, itaconic anhydride and dicumyl peroxide are respectively placed into a vacuum oven and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PE (EX5) (as a polyolefin), 4 parts of sorbitol (a polyhydroxy compound), 6 parts of itaconic anhydride (as a grafting agent) and 1 part of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixture; (3) The mixture is added to a twin-screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the cycle extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, and a plate is pressed in a flat vulcanization instrument.

[0064] Example 29 Example 29 is basically the same as Example 28, except that 4 parts of sorbitol are replaced by 8 parts of glycerol, and the rest is the same as Example 28.

[0065] Example 30 Example 30 is basically the same as Example 28, except that 4 parts of sorbitol are replaced by 8 parts of glucose, and the rest is the same as Example 28.

[0066] Example 31 Example 31 is basically the same as Example 28, except that 4 parts of sorbitol are replaced by 8 parts of xylitol, and the rest is the same as Example 28.

[0067] Example 32 The present embodiment provides a composition and a method for preparing a dynamically crosslinked material of a heterochain polymer / polyolefin mixed plastic based on the composition, which specifically comprises the following steps: (1) PET (CZ-318) particles, PE (EX5), sorbitol, itaconic anhydride and dicumyl peroxide are respectively placed in a vacuum oven and dried until the water content of the substances is less than 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 5 parts of PE (EX5) (as a polyolefin), 2.1 parts of sorbitol (a polyhydroxy compound), 3.2 parts of itaconic anhydride (as a grafting agent) and 0.5 parts of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixture; (3) The mixture is added to a twin-screw extruder through a hopper, and melt extrusion is carried out under nitrogen protection. The working parameters of the twin-screw extruder are as follows: the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30°C, 240°C, 250°C and 260°C respectively, and the cycle extrusion time is 5 minutes. Then, cooling and granulation are carried out to obtain the dynamically crosslinked material of the heterochain polymer / polyolefin mixed plastic, and a plate is pressed in a flat vulcanization instrument.

[0068] Example 33 The embodiment provides a composition and a method for preparing a heterochain polymer / polyolefin mixed plastic dynamic cross-linking material based on the composition, and specifically comprises the following steps: (1) PET (CZ-318) particles, PE (EX5), sorbitol, itaconic anhydride and dicumyl peroxide are respectively placed into vacuum ovens and dried until the water content of the substances is less than or equal to 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 2000 parts of PE (EX5) (as a polyolefin), 42 parts of sorbitol (a polyhydroxy compound), 63 parts of itaconic anhydride (as a grafting agent) and 10.5 parts of dicumyl peroxide (as a free radical initiator) are uniformly mixed to obtain a mixture; (3) The mixed material is added into a double-screw extruder through a hopper, and melt extrusion is carried out under the protection of nitrogen; the working parameters of the double-screw extruder are as follows: the feeding rotation speed is 15 rpm, the screw rotation speed is 30 rpm, the temperatures of four temperature zones are 30 DEG C, 240 DEG C, 250 DEG C and 260 DEG C respectively, and the circulation extrusion is carried out for 5 min; then cooling and granulation are carried out to obtain the heterochain polymer / polyolefin mixed plastic dynamic cross-linking material, and the material is pressed into a plate in a flat plate curing instrument.

[0069] Example 34 Example 34 is basically the same as example 32, and the difference is that 2.1 parts of sorbitol is replaced by 1 part of sorbitol, and the rest is the same as example 32.

[0070] Example 35 Example 35 is basically the same as example 33, and the difference is that 2.1 parts of sorbitol is replaced by 200 parts of sorbitol, and the rest is the same as example 33.

[0071] Example 36 Example 36 is basically the same as example 32, and the difference is that 3.2 parts of itaconic anhydride is replaced by 1 part of itaconic anhydride, and the rest is the same as example 32.

[0072] Example 37 Example 37 is basically the same as example 32, and the difference is that 0.5 parts of dicumyl peroxide is replaced by 0.25 parts of dicumyl peroxide, and the rest is the same as example 32.

[0073] Example 38 Example 38 is basically the same as example 33, and the difference is that 63 parts of itaconic anhydride is replaced by 200 parts of itaconic anhydride, and the rest is the same as example 33.

[0074] Example 39 Example 39 is substantially the same as Example 33, except that 10.5 parts of dicumyl peroxide is replaced by 40 parts of dicumyl peroxide, and the rest is the same as Example 33, which is not described here.

[0075] Comparative Example 1 Comparative Example 1 is different from Example 27 in that Comparative Example 1 does not use grafting agent itaconic anhydride and free radical initiator dicumyl peroxide, and the rest is the same as Example 27, which is not described here.

[0076] Comparative Example 2 Comparative Example 2 is different from Comparative Example 1 in that the heterochain polymer used in Comparative Example 2 is different, and the processing temperature is also changed, including the following steps: (1) PC-6600 particles, PE (EX5) powder and sorbitol were respectively placed in a vacuum oven and dried to a water content of less than 0.3%; (2) 100 parts of PC-6600 particles (as a heterochain polymer), 100 parts of PE (EX5) powder (as a polyolefin), and 4 parts of sorbitol (as a chain breaking agent) were mixed to obtain a mixture; (3) The mixture was added to a double screw extruder through a hopper, and was melt-extruded, cooled and granulated under nitrogen protection, and was pressed into a plate in a flat vulcanizing instrument; the working parameters of the double screw extruder were that the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 220, 230 and 240°C respectively, and the cycle extrusion time was 5 min.

[0077] Comparative Example 3 Comparative Example 3 is different from Comparative Example 1 in that the heterochain polymer used in Comparative Example 3 is different, and the processing temperature is also changed, including the following steps: (1) Polyurethane (1170AU) particles, PE (EX5) powder and sorbitol were respectively placed in a vacuum oven and dried to a water content of less than 0.3%; (2) 100 parts of polyurethane (1170AU) particles (as a heterochain polymer), 100 parts of PE (EX5) powder (as a polyolefin), and 4 parts of sorbitol (as a chain breaking agent) were mixed to obtain a mixture; (3) The mixture was added to a double screw extruder through a hopper, and was melt-extruded, cooled and granulated under nitrogen protection, and was pressed into a plate in a flat vulcanizing instrument; the working parameters of the double screw extruder were that the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 180, 190 and 200°C respectively, and the cycle extrusion time was 5 min.

[0078] Comparative Example 4 (1) PET (CZ-318) particles, PE (EX5) powder, maleic anhydride and dicumyl peroxide were respectively placed in a vacuum oven and dried until the water content of the substances was less than 0.3%; (2) 100 parts of PET (CZ-318) particles (as a heterochain polymer), 100 parts of PE (EX5) powder (as a polyolefin), 4 parts of maleic anhydride (as a grafting agent) and dicumyl peroxide were uniformly mixed (as a free radical initiator) to obtain a mixture; (3) The mixed material was added to a twin-screw extruder through a hopper, and was melt-extruded, cooled and granulated under nitrogen protection, and then was pressed into a plate in a flat vulcanizing instrument; the working parameters of the twin-screw extruder were as follows: the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 240, 250 and 260 ℃ respectively, and the cycle extrusion time was 5 min.

[0079] Comparative Example 5 The difference between Comparative Example 5 and Comparative Example 4 was only that the maleic anhydride was replaced by itaconic anhydride, and the other steps and parameters were unchanged.

[0080] Comparative Example 6 The difference between Comparative Example 6 and Comparative Example 4 was only that the dicumyl peroxide was replaced by benzoyl peroxide, and the other steps and parameters were unchanged.

[0081] Comparative Example 7 The difference between Comparative Example 7 and Example 1 was only that Comparative Example 7 did not use the grafting agent maleic anhydride, and the rest was the same as Example 1, which was not repeated here.

[0082] Comparative Example 8 The difference between Comparative Example 8 and Example 1 was only that Comparative Example 8 did not use the polyhydroxyl compound dipentaerythritol, and the rest was the same as Example 1, which was not repeated here.

[0083] Comparative Example 9 The difference between Comparative Example 9 and Example 1 was only that Comparative Example 9 did not use the free radical initiator dicumyl peroxide, and the rest was the same as Example 1, which was not repeated here.

[0084] Comparative Example 10 The difference between Comparative Example 10 and Example 1 was only that Comparative Example 10 did not use the grafting agent, the polyhydroxyl compound and the free radical initiator dicumyl peroxide, and the rest was the same as Example 1, which was not repeated here.

[0085] Figure 2 is the creep curve of the plate of the dynamic crosslinking material based on the heterochain polymer / polyolefin mixed plastic prepared in Example 1 and Comparative Example 10 at 80 ℃.

[0086] In addition, the tensile properties of the plate made of the above-mentioned dynamic cross-linking material based on the heterochain polymer / polyolefin mixed plastic after recycling for multiple times were verified, and the recycling method was as follows: the plate made in Example 1 was crushed, then was added into a double-screw extruder through a hopper and was melt-extruded and cooled to be granulated under nitrogen protection (the process conditions of melt-extrusion and cooling to be granulated were the same as those when the plate was newly made), and then was pressed into a plate in a flat vulcanization instrument. Figure 3 is the tensile curve of the plate made of the dynamic cross-linking material based on the heterochain polymer / polyolefin mixed plastic in Example 1 and after recycling for 3 times.

[0087] Figure 4 is the electron microscope image of the cross section of the unmodified blend in Example 1 (left image) and the electron microscope image of the cross section of the plate made of the dynamic cross-linking material of the modified mixed plastic (right image).

[0088] The thermal and mechanical properties of the plates made in the above-mentioned examples and comparative examples were tested, and the test method was as follows: The test sample of tensile strength, elongation at break and modulus was as follows: 5 g of the above-mentioned polymer mixed plastic dynamic cross-linking material made in the examples or comparative examples was placed in a tabletting mold, and then was pressed into a film sheet with a thickness of 0.25 mm in a flat vulcanization instrument (produced by Xiamen Yisite Instrument Co., Ltd.) at 180℃.

[0089] The tensile strength, elongation at break and Young's modulus were tested by a UTM4104-GD type high-low temperature universal tensile testing machine, the total length of the sample was 50 mm, the width was 5 mm, the thickness was 0.25 mm, the initial distance between the clamps was 20 mm, and the tensile speed was 50 mm / min.

[0090] The test results are shown in Table 1. Table 1: Mechanical properties and thermal properties of the plates made in the examples and comparative examples

[0091] As shown in Table 1, the tensile strength of the plate made of the dynamic cross-linking material based on the heterochain polymer / polyolefin mixed plastic prepared by the preparation method provided by the present application is 25 MPa or more, the elongation at break is 4.7% or more (for example, 4.7%-5.2%), and the modulus is 980 MPa or more. Compared with the plate made in the comparative examples, the examples still have high thermal and mechanical properties under the condition of adding the same mass of polyolefin.

[0092] Example 40 The present embodiment provides a recycling processing method of waste mixed plastic, which specifically comprises the following steps: Recycling mixed plastic products of plugboard (ABS) and mineral water bottle (PET) and upgrading and remanufacturing them: (1) Put the mixed plastic products, maleic anhydride, sorbitol and dicumyl peroxide into a vacuum oven respectively and dry them until the water content of the substances is below 0.3%; (2) Mix 200 parts of the mixed plastic products (containing 100 parts of ABS and 100 parts of PET by mass), 4 parts of maleic anhydride (as a grafting agent), 1 part of dicumyl peroxide (as a free radical initiator) and 6 parts of sorbitol to obtain a mixture; (3) Put the mixture into a double screw extruder through a hopper, melt extrude, cool and granulate under nitrogen protection, and press into a plate in a flat plate curing instrument; the working parameters of the double screw extruder are that the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30, 240, 250 and 260℃ respectively, and the cycle extrusion time is 5 min.

[0093] Example 41 The present example provides a recycling processing method of waste mixed plastics, which specifically comprises: Recycling mixed plastic products of mineral water bottle cap (PE) and mineral water bottle body (PET) and upgrading and remanufacturing them: (1) Put the mixed plastic products, maleic anhydride, sorbitol and dicumyl peroxide into a vacuum oven respectively and dry them until the water content of the substances is below 0.3%; (2) Mix 105 parts of the mixed plastic products (containing 5 parts of PE and 100 parts of PET by mass), 4 parts of itaconic anhydride (as a grafting agent), 1 part of dicumyl peroxide (as a free radical initiator) and 6 parts of sorbitol to obtain a mixture; (3) Put the mixture into a double screw extruder through a hopper, melt extrude, cool and granulate under nitrogen protection, and press into a plate in a flat plate curing instrument; the working parameters of the double screw extruder are that the feeding speed is 15 rpm, the screw speed is 30 rpm, the temperatures of the four temperature zones are 30, 240, 250 and 260℃ respectively, and the cycle extrusion time is 5 min.

[0094] Example 42 The present example provides a recycling processing method of waste mixed plastics, which specifically comprises: Recycling mixed plastic products of mineral water bottle cap (PE) and mineral water bottle body (PET) and mineral water bottle label (PP) and upgrading and remanufacturing them: (1) Put the mixed plastic products, itaconic anhydride, sorbitol and dicumyl peroxide into a vacuum oven respectively and dry them until the water content of the substances is below 0.3%; (2) 2100 parts of mixed plastic products (containing 1000 parts by mass of PE, 100 parts of PET and 1000 parts of PP), 4 parts of itaconic anhydride (as a grafting agent), 1 part of dicumyl peroxide (as a free radical initiator) and 6 parts of sorbitol were uniformly mixed to obtain a mixture; (3) The mixture was added into a twin-screw extruder through a hopper, and was melt-extruded, cooled and granulated under nitrogen protection, and was pressed into a plate in a flat vulcanization instrument; the working parameters of the twin-screw extruder were as follows: the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 240, 250 and 260 °C respectively, and the cycle extrusion time was 5 min.

[0095] Comparative Example 11 The difference between Comparative Example 11 and Example 40 is only that the mixed plastic products of recycled patch board (ABS) and mineral water bottle (PET) are directly melt-blended: (1) The mixed plastic products were respectively placed in a vacuum oven and dried to a water content of less than 0.3%; (2) 200 parts of mixed plastic products (containing 100 parts by mass of ABS and 100 parts of PET) were added into an extruder through a hopper to obtain a mixture; (3) The mixture was added into a twin-screw extruder through a hopper, and was melt-extruded, cooled and granulated under nitrogen protection, and was pressed into a plate in a flat vulcanization instrument; the working parameters of the twin-screw extruder were as follows: the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 240, 250 and 260 °C respectively, and the cycle extrusion time was 5 min.

[0096] Comparative Example 12 The difference between Comparative Example 12 and Example 41 is only that the mixed plastic products of recycled mineral water bottle cap (PE) and mineral water bottle (PET) are directly melt-blended: (1) The mixed plastic products were respectively placed in a vacuum oven and dried to a water content of less than 0.3%; (2) 105 parts of mixed plastic products were added into an extruder through a hopper to obtain a mixture; (3) The mixture was added into a twin-screw extruder through a hopper, and was melt-extruded, cooled and granulated under nitrogen protection, and was pressed into a plate in a flat vulcanization instrument; the working parameters of the twin-screw extruder were as follows: the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 240, 250 and 260 °C respectively, and the cycle extrusion time was 5 min.

[0097] Comparative Example 13 Comparative Example 13 and Example 42 differ only in that the mixed plastic products of the mineral water bottle cap (PE), the mineral water bottle (PET), and the mineral water bottle label (PP) are recovered and directly melt blended as follows: (1) The mixed plastic products were respectively placed in a vacuum oven and dried to a water content of 0.3% or less; (2) 2100 parts of the mixed plastic products were added to the extruder through a hopper to obtain a mixture; (3) The mixed material was added to a twin-screw extruder through a hopper, melt-extruded, cooled and granulated under nitrogen protection, and pressed into a plate in a flat vulcanizing instrument; the working parameters of the twin-screw extruder were as follows: the feeding speed was 15 rpm, the screw speed was 30 rpm, the temperatures of the four temperature zones were 30, 240, 250, and 260°C, respectively, and the cycle extrusion time was 5 min.

[0098] Table 2 Properties of the upgraded mixed plastic recycling products

[0099] The plastic recycling processing method provided by the application can be applied to the upgrading recycling of most commercial plastics and mixed waste plastics in different proportions, and has the advantages of simple operation, high efficiency, and excellent performance of the mixed plastic dynamic crosslinking material with a dynamic covalent crosslinking network. For example, when the mixed plastic is treated by the method, the tensile strength of the mixed plastic dynamic crosslinking material plate prepared when the PE content in the mixed plastic is 50% is maintained at 24 MPa or more. In addition, the PET / PE mixed plastic dynamic crosslinking material has a reduced melting point and excellent breaking strength and reprocessing performance, and the mechanical properties do not decrease significantly after multiple cycles of recycling, which is superior to existing PET / PE materials.

[0100] In addition, the inventors have also conducted tests on other raw materials, process operations, and process conditions described in the specification with reference to the foregoing examples, and all have obtained relatively ideal results.

[0101] The aspects, embodiments, features, and examples of the application should be considered illustrative, for the purpose of explanation, illustration, and description, but not for the purpose of limiting the application, the scope of which is defined only by the claims.

[0102] While the application has been described with reference to the illustrative embodiments, those skilled in the art will understand that various other changes, omissions, additions and / or modifications can be made without departing from the spirit and scope of the application. Further, many modifications can be made to adapt a particular situation or material to the teachings of the application without departing from its scope. Therefore, it is intended that the application not be limited to the disclosed embodiments, but will include all embodiments falling within the scope of the appended claims.

Claims

1. A composition for preparing a hybrid plastic dynamic crosslinking material, characterized in that, By weight, it includes: Heterochain polymer, wherein the heterochain polymer is a polymer containing one or more heteroatoms selected from oxygen, nitrogen, sulfur, silicon, and phosphorus in its main chain: 100 parts by mass; Polyolefins: 5 parts by weight to 2000 parts by weight; Polyhydroxy compounds: 1 part by weight to 200 parts by weight; Grafting agent: 1 part by weight to 200 parts by weight; Free radical initiator: 0.25 parts by weight to 40 parts by weight.

2. The composition according to claim 1, characterized in that: The polyolefins include one or more combinations of polyethylene, polypropylene, polystyrene, polybutene, ethylene-propylene copolymer, ethylene-acrylic acid copolymer, polyisobutylene, poly-1-butene, poly-1-pentene, poly-4-methyl-1-pentene, ethylene-1,2-octene copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol resin, acrylonitrile-butadiene-styrene copolymer, and acrylonitrile-styrene-acrylate rubber copolymer. And / or, the polyhydroxy compound contains two or more hydroxyl groups; let A be the higher of the melting point of the heterochain polymer and the melting point of the polyolefin, then the boiling point B of the polyhydroxy compound satisfies: B≥A+10℃; And / or, the grafting agent comprises a compound containing a carbon-carbon double bond and an anhydride group; And / or, the free radical initiator includes peroxides.

3. The composition according to claim 2, characterized in that: The heterochain polymer includes one or more of polyester, polyurethane, polycarbonate, and polyoxymethylene; preferably, the polyester includes one or more of polybutylene adipate / terephthalate, polylactic acid, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, poly(1,4-cyclohexanediol) terephthalate, polyethylene 2,6-naphthalenedicarboxylate, polybutylene 2,6-naphthalenedicarboxylate, ethylene glycol modified PCT copolyester, cis / trans-1,4-cyclohexanediol modified PET copolyester, polybutylene succinate, polyethylene 2,5-furandicarboxylate, poly(1,3-propanediol) 2,5-furandicarboxylate, and poly(1,4-butanediol) 2,5-furandicarboxylate. And / or, the polyhydroxy compound comprises one or more of the following: pentaerythritol, pentaerythritol, diethylene glycol, triethylene glycol, sorbitol, erythritol, glucose, maltose, sucrose, glycerol, diglyceride, xylitol, trimethylolethane, trimethylolpropane, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, methylpropanediol, neopentyl glycol, 1,4-cyclohexanediol, dipropylene glycol, triethanolamine, 2-di(2-hydroxyethyl)amino-2-hydroxymethyl-1,3-propanediol, and bis(2-hydroxyethyl)amino(trimethylol)methane; And / or, the grafting agent includes one or more of maleic anhydride, itaconic anhydride, citraconic anhydride, and nadic anhydride; And / or, the free radical initiator includes at least one of benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, tert-butyl peroxide, 2,2-di(tert-butylperoxy)butane, tert-butyl cumyl peroxide, diisopropyl peroxide, diisobutyl peroxide, tert-butyl perpentanoate, tert-pentanoate, dicyclohexyl peroxide, tert-butyl peroxyoctanoate, di(3,5,5-trimethylhexanoyl peroxide), tert-butylperoxyisopropyl carbonate, tert-butyl peroxide, tert-butyl peroxydioxide, tert-butyl peracetate, and ditert-butyl peroxide.

4. A composition for preparing a mixed plastic dynamic crosslinking material, characterized in that, By weight, it includes: The recycled waste mixed plastic is used to provide 100 parts by weight of a heterochain polymer and 5 to 2000 parts by weight of a polyolefin, wherein the heterochain polymer is a polymer containing any one or more heteroatoms of oxygen, nitrogen, sulfur, silicon, and phosphorus in its main chain. Polyhydroxy compounds: 1 part by weight to 200 parts by weight; Grafting agent: 1 part by weight to 200 parts by weight; Free radical initiator: 0.25 parts by weight to 40 parts by weight.

5. A method for preparing a hybrid plastic dynamic crosslinking material, characterized in that, include: In a protective atmosphere, the composition of any one of claims 1 to 4 is subjected to melt extrusion, during which the composition undergoes chain scission reaction, grafting reaction and dynamic crosslinking reaction, and then cooled and granulated to obtain a mixed plastic dynamic crosslinked material.

6. The preparation method according to claim 5, characterized in that: The temperature of the melt extrusion is 30℃~280℃.

7. A method for recycling and processing plastics, characterized in that, include: Waste mixed plastics to be recycled, wherein the waste mixed plastics contain 100 parts by weight of heterochain polymers and 5 to 2000 parts by weight of polyolefins, wherein the heterochain polymers are polymers containing any one or more heteroatoms of oxygen, nitrogen, sulfur, silicon, and phosphorus in the main chain. The waste mixed plastic is mixed with 1 part by weight to 200 parts by weight of a polyhydroxy compound, 1 part by weight to 200 parts by weight of a grafting agent and 0.25 parts by weight to 40 parts by weight of a free radical initiator to obtain a mixture. In a protective atmosphere, the mixture is melt-extruded, during which chain-breaking, grafting and dynamic cross-linking reactions occur in the mixture. Then, it is cooled and granulated to obtain a mixed plastic dynamic cross-linked material.

8. The method for recycling and processing plastics according to claim 7, characterized in that: The temperature of the melt extrusion is 30℃~280℃.

9. A hybrid plastic dynamic crosslinking material, characterized in that: It is prepared by the preparation method described in claim 5 or 6, or by the plastic recycling process described in claim 7 or 8.

10. A plastic product, characterized in that, Includes the hybrid plastic dynamic crosslinking material as described in claim 9.

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