Dynamic crosslinking type epoxy functionalized polyolefin elastomer as well as preparation method and application thereof

Abstract

The invention provides a dynamic crosslinking type epoxy functionalized polyolefin elastomer as well as a preparation method and application thereof. The dynamic crosslinking type epoxy functionalized polyolefin elastomer is prepared from the following raw materials: a polyolefin elastomer, a polar monomer, a comonomer, an initiator, a crosslinking agent and a catalyst. The preparation method comprises the following steps: firstly, grafting a polar monomer on a polyolefin elastomer under the assistance of a comonomer through a free radical grafting method to obtain an epoxy functionalized polyolefin elastomer; introducing a cross-linking agent and a catalyst into the epoxy functionalized polyolefin elastomer, and carrying out dynamic covalent cross-linking through an epoxy ring-opening reaction to finally obtain the dynamic cross-linking type epoxy functionalized polyolefin elastomer. The dynamic crosslinking type epoxy functionalized polyolefin elastomer prepared by the invention has strong cohesive force and strong adhesion, can be remodeled and recycled through transesterification, and can be used in the fields of adhesives, automobile industry, wires and cables, photovoltaic packaging, toughening modification and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of polyolefin elastomers. Specifically, it relates to a dynamically crosslinked epoxy-functionalized polyolefin elastomer and its preparation method and application. Background Art

[0002] As an advanced material for the copolymerization of ethylene and α-olefins, polyolefin elastomers not only possess the characteristics of high elasticity and low permanent deformation, but also exhibit the perfect combination of high strength and high elongation rate, ensuring their stability and durability in various applications. In addition, polyolefin elastomers have excellent processing properties, are suitable for a variety of molding processes, and their weather resistance and chemical resistance are also extremely outstanding, capable of effectively resisting the erosion of the external environment, thus greatly extending the service life of products. However, the non-polar characteristics of polyolefin elastomers, which are composed only of carbon and hydrogen elements, severely restrict their promotion and application in many fields. Non-polar means that the interaction between polyolefin elastomers and other polar materials or surfaces is weak, resulting in limitations in adhesion, coating, composite material preparation, etc. In addition, chemical crosslinking of polyolefin elastomers is usually required to obtain better mechanical strength, aging resistance, wear resistance, high elasticity, etc. However, this stable chemical crosslinking also makes the polymer insoluble and infusible once formed, difficult to recycle, and there has been a serious phenomenon of environmental pollution and resource depletion.

[0003] Therefore, if the surface properties and adhesion properties of polyolefin elastomers can be improved without losing the reversibility of the network, it will significantly increase their added value and endow them with sustainability. Summary of the Invention

[0004] The purpose of the present invention is to solve the application limitations of existing polyolefin elastomers due to non-polar characteristics, and provide a dynamically crosslinked epoxy-functionalized polyolefin elastomer and its preparation method and application to broaden the application of polyolefin elastomers in multiple key fields (such as adhesives, the automotive industry, wire and cable, photovoltaic encapsulation, and toughening modification), while alleviating the environmental burden caused by the non-recyclability of traditional chemical crosslinking.

[0005] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0006] A dynamically crosslinked epoxy-functionalized polyolefin elastomer, comprising the following components in parts by weight: 100 parts of polyolefin elastomer, 1 - 8 parts of polar monomer, 0 - 8 parts of comonomer, 0.05 - 1.6 parts of initiator, 0.1 - 5 parts of crosslinking agent, and 0.01 - 2.5 parts of catalyst.

[0007] Preferably, the polar monomer is at least one of glycidyl methacrylate, allyl glycidyl ether, glycidyl acrylate, 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene, and (S)-2-(but-3-en-1-yl)oxirane.

[0008] Preferably, the comonomer is at least one of styrene, 1-vinylimidazole, N-vinylpyrrolidone, and 3-vinylpyridine.

[0009] Preferably, the initiator is at least one of benzoyl peroxide, dicumyl peroxide, and di-tert-butyl peroxide cumene.

[0010] Preferably, the crosslinking agent is at least one of 4,4'-dicarboxydiphenyl ether, citric acid, 2,2'-dithiobibenzoic acid, isophthalic acid, 1,2,4-benzenetricarboxylic acid, pyromellitic acid, and 1,2,3,4-butanetetracarboxylic acid.

[0011] Preferably, the melt index of the polyolefin elastomer is 1-50 g / 10 min.

[0012] Preferably, the catalyst is at least one of zinc acetate, 1,2-dimethylimidazole, and 4-dimethylaminopyridine.

[0013] A method for preparing a dynamically crosslinked epoxy-functionalized polyolefin elastomer, comprising the following steps:

[0014] (1) First, heat and shear the polyolefin elastomer in a torque rheometer to make it into a molten state;

[0015] (2) Subsequently, quickly add the polar monomer, comonomer, and initiator to carry out a free radical grafting reaction. After the free radical grafting reaction is completed, an epoxy-functionalized polyolefin elastomer mixture is obtained;

[0016] (3) Weigh the epoxy-functionalized polyolefin elastomer mixture and heat it to dissolve in xylene. After it cools, add a poor solvent of the polyolefin elastomer and shake well. At this time, the liquid turns into a milky white solid-liquid mixture;

[0017] (4) Vacuum filter the milky white solid-liquid mixture obtained in step (3) to separate the milky white solid. Continuously wash the milky white solid three times with absolute ethanol, and then place the washed milky white solid in a drying oven to heat and dry until constant weight to obtain the epoxy-functionalized polyolefin elastomer;

[0018] (5) Add the epoxy-functionalized polyolefin elastomer, crosslinking agent, and catalyst obtained in step (4) to a two-roll mill for mixing. After the blend is uniformly mixed under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend is obtained;

[0019] (6) Hot press the epoxy-functionalized polyolefin elastomer compound to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0020] In the above method, in step (1), the high temperature condition is 120 - 170 °C, the shearing condition is 40 - 70 r / min, and the melting time is 1 - 4 min.

[0021] In the above method, in step (2), the ratio of polar monomer to polyolefin elastomer is 1 - 8%, the ratio of comonomer to polar monomer is 0 - 100%, and the ratio of initiator to polar monomer is 5 - 20%; the free radical grafting reaction time is 5 - 15 min.

[0022] In the above method, in step (3), the poor solvent of the polyolefin elastomer is at least one of methanol, absolute ethanol, water, and acetone; in step (4), the heating temperature of the drying oven is 30 - 80 °C.

[0023] In the above method, in step (5), the ratio of crosslinking agent to epoxy-functionalized polyolefin elastomer is 0.1 - 5%; the ratio of catalyst to crosslinking agent is 10 - 50%; the mixing time is 1 - 15 min.

[0024] In the above method, in step (6), the hot press temperature and time are 100 - 170 °C and 2 - 30 min, respectively.

[0025] A dynamically crosslinked epoxy-functionalized polyolefin elastomer is applied to the fields of adhesives, automotive industry, wire and cable, photovoltaic encapsulation, and toughening and modification.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) The preparation method of the dynamically crosslinked epoxy-functionalized polyolefin elastomer provided by the present invention is simple and effective and can meet the requirements of large-scale industrial production. This method does not rely on complex synthesis steps and the preparation process is environmentally friendly and pollution-free, conforming to the concept of green manufacturing. Through the deep integration of epoxy-functionalization design and dynamic crosslinking technology, the conversion of commercial polyolefin elastomers to dynamically crosslinked epoxy-functionalized polyolefin elastomers can be easily achieved. In addition, the network structure of the dynamically crosslinked epoxy-functionalized polyolefin elastomer is controllable, and its overall performance can be adjusted as needed.

[0028] (2) The dynamically crosslinked epoxy-functionalized polyolefin elastomer prepared by the present invention has high polarity, which broadens the application scope of polyolefin elastomers. The high-polarity characteristic enables it to easily establish a strong affinity with the matrix surface, thereby significantly enhancing the adhesion force. It is particularly suitable for adhesive application scenarios with extremely high adhesion requirements, effectively enhancing the stability and durability of structural components. Further, this strong polarity greatly enhances the compatibility and interaction force between the polyolefin elastomer and other materials, and can be applied in modified composite materials requiring high compatibility, thereby improving the overall performance of the materials.

[0029] (3) The dynamically crosslinked epoxy-functionalized polyolefin elastomer prepared by the present invention has a highly dynamic crosslinked network. This structure endows the material with unique recyclability and reprocessing ability. The crosslinked network is densely populated with dynamic β-hydroxy ester bonds, which can undergo efficient rearrangement under specific conditions (such as thermal excitation), thereby achieving flexible adjustment of the network topology. This characteristic enables the material to exhibit macroscopic fluidity at high temperatures, facilitating reprocessing and recycling, and greatly improving the resource utilization efficiency of the material. Description of the Drawings

[0030] Figure 1 Grafting rate of the epoxy-functionalized polyolefin elastomer in Examples 1-3.

[0031] Figure 2 Nuclear magnetic spectra of Example 5, Comparative Example 3, and pure polyolefin elastomer.

[0032] Figure 3 Infrared spectra of Example 5, Comparative Example 3, and pure polyolefin elastomer.

[0033] Figure 4 Scanning electron microscope photos of the brittle fracture surfaces of Example 8 and pure polyolefin elastomer.

[0034] Figure 5 Schematic diagram of the adhesion procedure process of the dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0035] Figure 6 Reversible transesterification chemical reaction during the network rearrangement process of the dynamically crosslinked epoxy-functionalized polyolefin elastomer. Detailed Embodiments

[0036] The embodiments described below are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0037] Example 1

[0038] In a torque rheometer, 100 g of polyolefin elastomer (875L, melt index: 5 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 170 °C for 1 min under shear action (rotation speed 70 r / min). Subsequently, 2 g of glycidyl methacrylate (Shanghai Macklin Biochemical Co., Ltd.), 1 g of N-vinylpyrrolidone (Shanghai Aladdin Biochemical Technology Co., Ltd.) and 0.2 g of dicumyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for free radical grafting reaction for 10 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of methanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 40 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 3.5 g of pyromellitic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 10 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 150 °C for 10 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0039] Example 2

[0040] In a torque rheometer, 100 g of polyolefin elastomer (875L, melt index: 5 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 170 °C for 1 min under shear action (rotation speed 70 r / min). Subsequently, 4 g of glycidyl methacrylate (Shanghai Macklin Biochemical Co., Ltd.), 2 g of N-vinylpyrrolidone (Shanghai Aladdin Biochemical Technology Co., Ltd.) and 0.5 g of dicumyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for free radical grafting reaction for 10 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of methanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 40 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 3.5 g of pyromellitic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 10 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 150 °C for 10 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0041] Example 3

[0042] In a torque rheometer, 100 g of polyolefin elastomer (875L, melt index: 5 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 170 °C for 1 min under shear action (rotation speed 70 r / min). Subsequently, 6 g of glycidyl methacrylate (Shanghai Macklin Biochemical Co., Ltd.), 3 g of N-vinylpyrrolidone (Shanghai Aladdin Biochemical Technology Co., Ltd.), and 0.6 g of dicumyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 10 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated to dissolve in 100 mL of xylene. After cooling, 200 mL of methanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 40 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. 100 g of the above epoxy-functionalized polyolefin elastomer, 3.5 g of pyromellitic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.), and 0.69 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 10 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 150 °C for 10 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0043] Example 4

[0044] In a torque rheometer, 100 g of polyolefin elastomer (8730L, melt index: 30 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 140 °C for 2 min by shear action (rotation speed 60 r / min). Subsequently, 3 g of allyl glycidyl ether (Shanghai Macklin Biochemical Co., Ltd.), 3 g of styrene (Shanghai Macklin Biochemical Co., Ltd.) and 0.12 g of dibenzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for free radical grafting reaction for 8 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of absolute ethanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 60 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. 100 g of the above epoxy-functionalized polyolefin elastomer, 1.85 g of citric acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of 1,2-dimethylimidazole (catalyst) were successively added to a two-roll mill for mixing. The blend was mixed for 15 min under the action of high-speed shear force to obtain an epoxy-functionalized polyolefin elastomer blend. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 130 °C for 15 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0045] Example 5

[0046] In a torque rheometer, 100 g of polyolefin elastomer (8730L, melt index: 30 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 140 °C for 2 min under shear action (rotation speed 60 r / min). Subsequently, 3 g of allyl glycidyl ether (Shanghai Macklin Biochemical Co., Ltd.), 3 g of styrene (Shanghai Macklin Biochemical Co., Ltd.) and 0.24 g of dibenzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 8 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of absolute ethanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 60 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 1.85 g of citric acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of 1,2-dimethylimidazole (catalyst) were successively added to a two-roll mill for mixing. After the blend was mixed under the action of high-speed shear force for 15 min, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 130 °C for 15 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0047] Example 6

[0048] In a torque rheometer, 100 g of polyolefin elastomer (8730L, melt index: 30 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 140 °C for 2 min by shear action (rotation speed 60 r / min). Subsequently, 3 g of allyl glycidyl ether (Shanghai Macklin Biochemical Co., Ltd.), 3 g of styrene (Shanghai Macklin Biochemical Co., Ltd.) and 0.36 g of dibenzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 8 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated to dissolve in 100 mL of xylene. After cooling, 200 mL of absolute ethanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 60 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 1.85 g of citric acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of 1,2-dimethylimidazole (catalyst, Shanghai Aladdin Biochemical Technology Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 15 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 130 °C for 15 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0049] Example 7

[0050] In a torque rheometer, 100 g of polyolefin elastomer (8613, melt index: 13 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 160 °C for 3 min under shear action (rotation speed 50 r / min). Subsequently, 7 g of glycidyl acrylate (Shanghai Macklin Biochemical Co., Ltd.), 1.75 g of 1-vinylimidazole (Shanghai Macklin Biochemical Co., Ltd.) and 0.84 g of di-tert-butyl peroxyisopropylbenzene (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 12 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of water was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 70 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 4.2 g of 2,2'-dithiobisbenzoic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.42 g of 4-dimethylaminopyridine (catalyst, Shanghai Aladdin Biochemical Technology Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 8 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 170 °C for 6 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0051] Example 8

[0052] In a torque rheometer, 100 g of polyolefin elastomer (8613, melt index: 13 g / 10 min, SK Group Co., Ltd., South Korea) was first melted at 160 °C for 3 min under shear action (rotation speed 50 r / min). Subsequently, 7 g of 1,2-epoxy-5-hexene (Shanghai Macklin Biochemical Co., Ltd.), 1.75 g of 1-vinylimidazole (Shanghai Macklin Biochemical Co., Ltd.) and 0.84 g of di-tert-butyl peroxyisopropylbenzene (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 12 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of water was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 70 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 4.2 g of 2,2'-dithiobisbenzoic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.42 g of 4-dimethylaminopyridine (catalyst, Shanghai Aladdin Biochemical Technology Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 8 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 170 °C for 6 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0053] Example 9

[0054] In a torque rheometer, 100 g of polyolefin elastomer (8613, melt index: 13 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 160 °C for 3 min under shear action (rotation speed 50 r / min). Subsequently, 7 g of (S)-2-(but-3-en-1-yl)oxirane (Shanghai Macklin Biochemical Co., Ltd.), 1.75 g of 1-vinylimidazole (Shanghai Macklin Biochemical Co., Ltd.) and 0.84 g of di-tert-butyl peroxyisopropylbenzene (Shanghai Macklin Biochemical Co., Ltd.) were added for a radical grafting reaction for 12 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated to dissolve in 100 mL of xylene. After cooling, 200 mL of water was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 70 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 4.2 g of 2,2'-dithiobisbenzoic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.42 g of 4-dimethylaminopyridine (catalyst, Shanghai Aladdin Biochemical Technology Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 8 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 170 °C for 6 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0055] Example 10

[0056] In a torque rheometer, 100 g of polyolefin elastomer (8407, melt index: 30 g / 10 min, Dow Chemical, USA) was first melted at 130 °C for 4 min by shear action (rotation speed 40 r / min). Subsequently, 5 g of 1,2-epoxy-7-octene (Shanghai Macklin Biochemical Co., Ltd.), 3.75 g of 3-vinylpyridine (Shanghai Macklin Biochemical Co., Ltd.) and 0.75 g of benzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 14 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of acetone was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 50 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 3.5 g of 4,4'-dicarboxydiphenyl ether (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 1.05 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 12 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 140 °C for 20 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0057] Example 11

[0058] In a torque rheometer, 100 g of polyolefin elastomer (8407, melt index: 30 g / 10 min, Dow Chemical, USA) was first melted at 130 °C for 4 min by shear action (rotation speed 40 r / min). Subsequently, 5 g of 1,2-epoxy-7-octene (Shanghai Macklin Biochemical Co., Ltd.), 3.75 g of 3-vinylpyridine (Shanghai Macklin Biochemical Co., Ltd.) and 0.75 g of benzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for free radical grafting reaction for 14 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated to dissolve in 100 mL of xylene. After cooling, 200 mL of acetone was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in a drying oven at 50 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. 100 g of the above epoxy-functionalized polyolefin elastomer, 3.5 g of 1,2,4-benzenetricarboxylic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 1.05 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. The blend was mixed for 12 min under the action of high-speed shear force to obtain an epoxy-functionalized polyolefin elastomer blend. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 140 °C for 20 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0059] Example 12

[0060] In a torque rheometer, 100 g of polyolefin elastomer (8407, melt index: 30 g / 10 min, Dow Chemical, USA) was first melted at 130 °C for 4 min under shear action (rotation speed 40 r / min). Subsequently, 5 g of 1,2-epoxy-7-octene (Shanghai Macklin Biochemical Co., Ltd.), 3.75 g of 3-vinylpyridine (Shanghai Macklin Biochemical Co., Ltd.) and 0.75 g of benzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for free radical grafting reaction for 14 min. After the grafting reaction, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of acetone was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 50 °C until a constant weight was obtained, and an epoxy-functionalized polyolefin elastomer was obtained. The above 100 g of epoxy-functionalized polyolefin elastomer, 3.5 g of 1,2,3,4-butanetetracarboxylic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 1.05 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. The blend was mixed for 12 min under the action of high-speed shear force to obtain an epoxy-functionalized polyolefin elastomer blend. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 140 °C for 20 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0061] Comparative Example 1

[0062] The polyolefin elastomer (875L, melt index: 5 g / 10 min, SK Group Co., Ltd., Korea), 3.5 g of pyromellitic acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of zinc acetate (catalyst, Tianjin Fuchen Chemical Reagent Co., Ltd.) were successively added to a two-roll mill for mixing. The blend was mixed for 10 min under the action of high-speed shear force to obtain a polyolefin elastomer blend. The polyolefin elastomer blend was hot-pressed at 150 °C for 10 min to obtain a polyolefin elastomer blend.

[0063] Comparative Example 2

[0064] In a torque rheometer, 100 g of polyolefin elastomer (8730L, melt index: 30 g / 10 min, SK Group Co., Ltd., Korea) was first melted at 140 °C for 2 min under shear action (rotation speed 60 r / min). Subsequently, 3 g of allyl glycidyl ether (Shanghai Macklin Biochemical Co., Ltd.) and 3 g of styrene (Shanghai Macklin Biochemical Co., Ltd.) were added, and a free radical grafting reaction was carried out for 8 min. After the grafting reaction was completed, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated and dissolved in 100 mL of xylene. After cooling, 200 mL of absolute ethanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 60 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 1.85 g of citric acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of 1,2-dimethylimidazole (catalyst, Shanghai Aladdin Biochemical Technology Co., Ltd.) were successively added to a two-roll mill for mixing. After the blend was mixed for 15 min under the action of high-speed shear force, an epoxy-functionalized polyolefin elastomer blend was obtained. The epoxy-functionalized polyolefin elastomer blend was hot-pressed at 130 °C for 15 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0065] Comparative Example 3

[0066] In a torque rheometer, 100 g of polyolefin elastomer (8730L, melt index: 30 g / 10 min, SK Group Co., Ltd., South Korea) was first melted at 140 °C for 2 min under shear action (rotation speed 60 r / min). Subsequently, 3 g of allyl glycidyl ether (Shanghai Macklin Biochemical Co., Ltd.) and 0.24 g of dibenzoyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added for a free radical grafting reaction for 8 min. After the grafting reaction ended, an epoxy-functionalized polyolefin elastomer mixture was obtained. 10 g of the above epoxy-functionalized polyolefin elastomer mixture was weighed and heated to dissolve in 100 mL of xylene. After cooling, 200 mL of absolute ethanol was added and shaken well, and the liquid turned into a milky white solid-liquid mixture. The milky white solid-liquid mixture was separated by vacuum filtration to obtain a milky white solid, which was continuously washed three times with absolute ethanol. The obtained product was heated and dried in an oven at 60 °C until constant weight to obtain an epoxy-functionalized polyolefin elastomer. The above 100 g of epoxy-functionalized polyolefin elastomer, 1.85 g of citric acid (crosslinking agent, Shanghai Macklin Biochemical Co., Ltd.) and 0.69 g of 1,2-dimethylimidazole (catalyst) were successively added to a two-roll mill for mixing. The blend was mixed for 15 min under the action of high-speed shear force to obtain an epoxy-functionalized polyolefin elastomer blend. The epoxy-functionalized polyolefin elastomer blend was hot pressed at 130 °C for 15 min to obtain a dynamically crosslinked epoxy-functionalized polyolefin elastomer.

[0067] Comparative Example 4

[0068] 100 g of polyolefin elastomer (8613, melt index: 13 g / 10 min, SK Group Co., Ltd., South Korea) and 2 g of dicumyl peroxide (Shanghai Macklin Biochemical Co., Ltd.) were added to a two-roll mill for mixing. The blend was mixed for 8 min under the action of high-speed shear force to obtain a polyolefin elastomer blend. The polyolefin elastomer blend was hot pressed at 170 °C for 6 min to obtain a permanently crosslinked polyolefin elastomer.

[0069] Performance Test

[0070] Grafting rate test: 0.5 g of epoxy-functionalized polyolefin elastomer was weighed and heated to dissolve in 70 mL of xylene. Then, 10 mL of a 0.1 mol / L trichloroacetic acid-xylene standard solution was added. After heating under reflux for 2 h, 2 drops of phenolphthalein indicator (10 g / L) were added, and it was titrated to the end point with a 0.1 mol / L KOH-ethanol standard solution, and a blank experiment was conducted. The grafting rate was calculated according to the following formula, and the test results are shown in Table 1.

[0071]

[0072] Among them, GD is the grafting degree, %; N is the concentration of the KOH / CH3OH solution used in the titration process, mol / L; V2 and V1 are the volumes (mL) of the KOH / CH3OH solution consumed in titrating the blank sample and the epoxy-functionalized polyolefin elastomer, respectively; M is the molecular weight of the polar monomer, g / mol; m is the mass of the titrated epoxy-functionalized polyolefin elastomer, g.

[0073] Figure 1 It shows that in Examples 1-3, as the amount of the polar monomer increases, the grafting rate of the epoxy-functionalized polyolefin elastomer shows a gradually increasing trend, indicating that the increase in the polar monomer concentration promotes its grafting rate on the polyolefin elastomer backbone.

[0074] Figure 2 and Figure 3 respectively show the nuclear magnetic spectroscopy and infrared spectroscopy of the epoxy-functionalized polyolefin elastomer in Example 5. Compared with the pure polyolefin elastomer and the epoxy-functionalized polyolefin elastomer in Comparative Example 3, Example 5 shows a lower ratio of the area of hydrogen atoms (S a / S b , hydrogen atoms on tertiary carbon / hydrogen atoms on methyl), indicating that the polar monomer grafts onto the polyolefin elastomer backbone by attacking the hydrogen atoms on the tertiary carbon. Meanwhile, in the infrared spectrum, Example 5 shows a significantly enhanced epoxy-related characteristic peak at 871 cm -1 , further indicating the high grafting rate of the polar monomer on the polyolefin elastomer under the combined action of the initiator and the comonomer.

[0075] Figure 4 It shows the scanning electron microscope photos of Example 8 and the pure polyolefin elastomer. It can be seen that the pure polyolefin elastomer and Example 8 have similar surface roughness, indicating that the chemical grafting and dynamic covalent crosslinking of the polyolefin elastomer do not change the microscopic morphology of the elastomer.

[0076] Adhesion performance test: The polyolefin elastomer film was cut into small pieces 1 mm thick and with an area of (2 cm × 2 cm), and placed between two overlapping aluminum plates. These overlapping aluminum plates were placed on a hot press at 150 °C and pressed for 10 min under a constant force (~10 N) and then cooled. The bonded aluminum plates were respectively clamped at both ends of a universal testing machine, and the upper clamp was raised at a speed of 10 mm / min to measure the adhesion strength. The test results are shown in Table 1. Figure 5 It shows the adhesion process of the polyolefin elastomer film.

[0077] Recycling performance test: The polyolefin elastomer material was cut into millimeter-sized fragments and then hot-pressed again at 130 °C for 5 min. The recycled samples were cut into standard specimens for uniaxial tensile experiments. The recycling efficiency was evaluated by the ratio of the ultimate tensile strength of the recycled sample to the ultimate tensile strength of the original material. The test results are shown in Table 1.

[0078] Figure 6 It shows the rearrangement process of the network topology of the dynamically crosslinked epoxy-functionalized polyolefin elastomer. Under the action of heat, the dynamic β-hydroxy ester bonds can break and recombine without changing the crosslinking density. The reconstruction of the network can achieve the recycling of the dynamically crosslinked epoxy-functionalized polyolefin elastomer, thereby restoring most of the mechanical properties.

[0079] Table 1

[0080]

[0081] Combined with Table 1, the gradual increase of the polar monomer within a certain range in Examples 1-3 can improve its grafting rate on the polyolefin elastomer, thereby improving the adhesion strength of the polyolefin elastomer on the aluminum plate. At the same time, dynamic covalent crosslinking can ensure the dynamicity of the polyolefin elastomer to achieve recycling. Compared with the comparative examples, Examples 1-3 have higher polarity due to the grafting of polar monomers and dynamic crosslinking, thus significantly enhancing the adhesion strength of the polyolefin elastomer. With the gradual increase of the initiator content, the grafting rate and adhesion strength in Examples 4-6 both increase first and then decrease, indicating the importance of reasonably adjusting the initiator dosage. In addition, the grafting rate of Comparative Example 2 without adding an initiator is 0, and the adhesion strength is also low. Compared with Examples 4-6, the grafting rate of Comparative Example 3 with an initiator but without a comonomer added is lower, and the adhesion strength also decreases accordingly. These results demonstrate the necessity of initiators and comonomers. Different grafting monomers were used in Examples 7-9, and both high grafting rates and adhesion strengths were achieved, indicating the universality of this method. Different functional crosslinking agents were used in Examples 10-12, but similar adhesion strengths and recovery rates were achieved, indicating the versatility of different functional crosslinking agents in dynamic crosslinking. In addition, compared with Comparative Example 4 with permanent crosslinking, Examples 1-9 with high adhesion strength achieved higher recovery rates due to the highly dynamic characteristics of the dynamic covalent crosslinking network.

Claims

1. A dynamically crosslinked epoxy-functionalized polyolefin elastomer, characterized in that, It comprises components in the following parts by weight: 100 parts of polyolefin elastomer, 1 - 8 parts of polar monomer, 0 - 8 parts of comonomer, 0.05 - 1.6 parts of initiator, 0.1 - 5 parts of crosslinking agent, and 0.01 - 2.5 parts of catalyst; The polar monomer is at least one of glycidyl methacrylate, allyl glycidyl ether, glycidyl acrylate, 1,2 - epoxy - 5 - hexene, 1,2 - epoxy - 7 - octene, and (S)-2-(but - 3 - en - 1 - yl)oxirane; The comonomer is at least one of styrene, 1 - vinylimidazole, N - vinylpyrrolidone, and 3 - vinylpyridine; The initiator is at least one of dibenzoyl peroxide, di - isopropylbenzene peroxide, and di - tert - butyl peroxyisopropylbenzene; The crosslinking agent is at least one of 4,4'-dicarboxydiphenyl ether, citric acid, 2,2’-dithiobisbenzoic acid, isophthalic acid, 1,2,4 - benzenetricarboxylic acid, pyromellitic acid, 1,2,3,4 - butanetetracarboxylic acid; 2. The dynamic crosslinked epoxy-functionalized polyolefin elastomer according to claim 1, wherein The melt index of the polyolefin elastomer is 1 - 50 g / 10 min.

3. The dynamic crosslinking type epoxy-functionalized polyolefin elastomer according to claim 1, characterized in that, The catalyst is at least one of zinc acetate, 1,2 - dimethylimidazole, and 4 - dimethylaminopyridine.

4. The preparation method of the dynamically crosslinked epoxy-functionalized polyolefin elastomer according to claim 1, characterized in that, It includes the following steps: (1) First, subject the polyolefin elastomer to high temperature and shear in a torque rheometer to make it into a molten state; (2) Subsequently, quickly add the polar monomer, comonomer, and initiator for free - radical grafting reaction. After the free - radical grafting reaction, an epoxy - functionalized polyolefin elastomer mixture is obtained; (3) Weigh the epoxy - functionalized polyolefin elastomer mixture and heat it to dissolve in xylene. After it cools, add a poor solvent of the polyolefin elastomer and shake well. At this time, the liquid turns into a milky white solid - liquid mixture; (4) Vacuum - filter the milky white solid - liquid mixture obtained in step (3) to separate the milky white solid. Continuously wash the milky white solid three times with absolute ethanol, and then place the washed milky white solid in a drying oven to heat - dry until constant weight to obtain the epoxy - functionalized polyolefin elastomer; (5) Add the epoxy - functionalized polyolefin elastomer, crosslinking agent, and catalyst obtained in step (4) to a two - roll mill for mixing. After the blend is uniformly mixed under the action of high - speed shear force, an epoxy - functionalized polyolefin elastomer blend is obtained; (6) Thermally press - mold the epoxy - functionalized polyolefin elastomer blend to obtain a dynamically cross - linked epoxy - functionalized polyolefin elastomer.

5. The preparation method according to claim 4, characterized in that, In step (1), the high - temperature condition is 120 - 170 °C, the shear condition is 40 - 70 r / min, and the melting time is 1 - 4 min.

6. The preparation method according to claim 4, characterized in that, In step (2), the ratio of polar monomer / polyolefin elastomer is 1 - 8%, the ratio of comonomer / polar monomer is 0 - 100%, and the ratio of initiator / polar monomer is 5 - 20%; the free - radical grafting reaction time is 5 - 15 min.

7. The preparation method according to claim 4, characterized in that, In step (3), the poor solvent of the polyolefin elastomer is at least one of methanol, absolute ethanol, water, and acetone; in step (4), the heating temperature of the drying oven is 30 - 80 °C.

8. The preparation method according to claim 4, characterized in that, In step (5), the ratio of the crosslinking agent to the epoxy-functionalized polyolefin elastomer is 0.1-5%; the ratio of the catalyst to the crosslinking agent is 10-50%; and the mixing time is 1-15 min.

9. The preparation method according to claim 4, characterized in that, In step (6), the hot pressing temperature and time are 100-170 °C and 2-30 min, respectively.

10. Use of the dynamically crosslinked epoxy-functionalized polyolefin elastomer according to any one of claims 1 to 3, characterized in that, The dynamic crosslinked epoxy-functionalized polyolefin elastomer is used in the fields of adhesives, the automotive industry, wire and cable, photovoltaic encapsulation, and toughening modification.

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