A polyolefin elastomer material and its preparation method

Abstract

This invention discloses a polyolefin elastomer material and its preparation method. The polyolefin elastomer molecular chain contains Si-O or Si-N bond structures, and the molar ratio of Si-O or Si-N bonds to C-C bonds in the polyolefin elastomer is 0.0001%-1%. The preparation method of the polyolefin elastomer is as follows: a solvent, comonomer, cocatalyst, main catalyst, and ω-olefin-based halosilane are added to an anhydrous and oxygen-free reactor. After the polymerization temperature reaches a set value, ethylene or propylene gas is introduced to a set polymerization pressure to start the polymerization reaction. After polymerization, a mixed slurry or mixed solution of the additive and solvent is introduced into the product solution system. After stirring, a solution rich in the polyolefin elastomer is obtained. Subsequently, devolatilization and granulation are performed to obtain granular polyolefin elastomer. This polyolefin elastomer has the characteristic of controllable long branch content and exhibits outstanding characteristics such as high melt strength, high tensile modulus, and significant rheological shear thinning phenomenon during processing and use.

Description

Technical Field

[0001] This invention belongs to the field of polyolefin elastomer production, and relates to a polyolefin elastomer material and its preparation method. Specifically, this invention relates to a polyolefin elastomer material containing Si-O bonds or Si-N bonds and its preparation method. Background Technology

[0002] Polyolefin elastomers mainly include polyethylene elastomers and polypropylene elastomers. They possess advantages such as high elasticity, ease of processing, high transparency, and good toughening and modification effects, and are widely used in photovoltaics, plastic modification, foaming, and other fields. Polyethylene elastomers are copolymers of ethylene and α-olefins (such as 1-butene, 1-hexene, and 1-octene), while polypropylene elastomers are copolymers of propylene and α-olefins (such as ethylene, 1-butene, and 1-hexene). Both elastomers have short-branched molecular chains, making it difficult to prepare polyolefin elastomers with long-branched structures. To improve the melt strength, melt flowability, and processing stability of polyolefin products, it is often necessary to introduce long-branched structures into the molecular chain of polyolefin materials. However, long-chain α-olefin macromonomers are difficult to coordinate with ethylene and insert into the polymer chain due to their large steric hindrance. Therefore, preparing polyolefin elastomers with long-branched structures has always been a challenge.

[0003] Furthermore, existing polyolefin elastomer materials are all based on C-C bonds, making them difficult to recycle. Achieving efficient recycling and reuse of polyolefin elastomer materials has always been a development trend.

[0004] The literature Macromolecules, 2018, 51, 8790, reports a method for preparing long-branched comb-shaped polyolefin elastomers (CPOEs) through cascade polymerization. This method involves homopolymerizing ethylene to prepare crystalline PE macromonomers (PE-M) with terminal double bonds, followed by ternary copolymerization of ethylene / 1-octene / PE-M to obtain CPOE. The resulting CPOE has a backbone of ethylene / 1-octene random copolymer and crystalline PE branches with controllable branch length and number, exhibiting excellent mechanical, processing, and thermal properties. However, this method suffers from high catalytic system cost, low catalytic activity, and complex process, and the main molecular chain of the product is composed of C-C bonds, making recycling difficult.

[0005] Besides direct synthesis, long-branched polyolefin elastomers can also be prepared by high-energy radiation and melt branching. However, high-energy radiation has the problems of complex process and high cost. Although melt branching is simple to operate and more economical, making it more suitable for large-scale industrial production, it inevitably has problems such as high-temperature degradation and side reactions.

[0006] Direct synthesis remains the development trend for long-branched polyolefin elastomers, but how to cleverly introduce long-branched structures into polymer molecular chains remains a challenge. Summary of the Invention

[0007] In view of the above problems, the present invention provides a polyolefin elastomer material and its preparation method. The polyolefin elastomer material of the present invention has the characteristics of controllable long branch content, and has the outstanding characteristics of high melt strength and significant rheological shear thinning phenomenon during processing and use. It can be widely used in the production of products in the fields of film, foam, and fiber, and can improve the mechanical properties, thermal stability, foaming performance and wear resistance of products.

[0008] To achieve the above objectives, one objective of the present invention is to provide a polyolefin elastomer material, wherein the polyolefin elastomer molecular chain contains a Si-O bond structure or a Si-N bond structure, and the molar ratio of Si-O bonds or Si-N bonds to C-C bonds in the polyolefin elastomer is 0.0001%-1%.

[0009] In the polyolefin elastomer of the present invention, the Si-O bond is obtained by the reaction of the Si-Cl bond or the Si-Br bond with the OH bond, and the Si-N bond is obtained by the reaction of the Si-Cl bond or the Si-Br bond with the NH bond.

[0010] Another objective of this invention is to provide a method for preparing the polyolefin elastomer: a solvent, comonomer, cocatalyst, main catalyst, and ω-olefin-based halosilane are added to an anhydrous and oxygen-free reactor. After the polymerization temperature reaches a set value, ethylene or propylene gas is introduced to a set polymerization pressure to start the polymerization reaction. After polymerization, a mixed slurry or mixed solution of the additive and solvent is introduced into the product solution system. After stirring, a solution rich in the polyolefin elastomer is obtained. Subsequently, devolatilization and granulation are performed to obtain granular polyolefin elastomer.

[0011] The solvent described in this invention is selected from one or more of n-pentane, isopentane, n-hexane, cyclohexane, n-heptane, 2-methylhexane, 3-methylhexane, isoparaffin Isopar C, and isoparaffin Isopar E.

[0012] The comonomers described in this invention are selected from one or more of 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene.

[0013] The main catalyst described in this invention is selected from one or more of the following: bridged metallocene catalysts, non-bridged metallocene catalysts, and restricted geometry catalysts.

[0014] The cocatalyst described in this invention is selected from one or more of methylaluminoxane, modified methylaluminoxane, tris(pentafluorophenyl)borane, borate, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum.

[0015] The ω-olefin halosilane of the present invention has 1, 2 or 3 Si-X bonds (X is Cl or Br), and the olefin group is a straight-chain or branched α-olefin group with 1-50 carbon atoms. Preferably, the ω-olefinic halosilane is selected from 9-decenyldimethylchlorosilane, 9-decenylmethyldichlorosilane, 9-decenyltrichlorosilane, 9-decenyldiethylchlorosilane, 9-decenylethyldichlorosilane, 8-nonenyldimethylchlorosilane, 8-nonenylmethyldichlorosilane, 8-nonenyltrichlorosilane, 8-nonenyldiethylchlorosilane, 8-nonenylethyldichlorosilane, 7-octenyldimethylchlorosilane, 7-octenylmethyldichlorosilane, 7-octenyltrichlorosilane, 7-octenyldiethylchlorosilane, 7-octenylethyldichlorosilane, 6-heptenyldimethylchlorosilane, 6-heptenylmethyldichlorosilane. One or more of the following: 6-heptenyltrichlorosilane, 6-heptenyldiethylchlorosilane, 6-heptenylethyldichlorosilane, 5-hexenyldimethylchlorosilane, 5-hexenylmethyldichlorosilane, 5-hexenyltrichlorosilane, 5-hexenyldiethylchlorosilane, 5-hexenylethyldichlorosilane, 4-pentenyldimethylchlorosilane, 4-pentenylmethyldichlorosilane, 4-pentenyltrichlorosilane, 4-pentenyldiethylchlorosilane, 4-pentenylethyldichlorosilane, 3-butenyldimethylchlorosilane, 3-butenylmethyldichlorosilane, 3-butenyltrichlorosilane, 3-butenyldiethylchlorosilane, and 3-butenylethyldichlorosilane.

[0016] According to the method for preparing polyolefin elastomer of the present invention, the polymerization time is 5-180 min, the polymerization temperature is 100-180℃, the polymerization pressure is 10-60 bar, the content of the additive in the mixed slurry or mixed solution of the additive and solvent is 1-50 wt%, the additive is selected from one or more of nano silica, cage-like polysilsesquioxane, polysilazane, and hexamethylcyclotrisilazane, and the additive contains at least 2 -OH hydroxyl groups or at least 2 -NH2 amino groups or at least 2 -NH imino groups. Preferably, the cage-like polysilsesquioxane auxiliaries are selected from one or more of octa(3-hydroxy-3-methylbutyldimethylsiloxane), octa(aminophenyltrioxane), N-phenylamino-cage-like polysilsesquioxane (CAS: 1708993-28-5), octamaleic acid cage-like polysilsesquioxane, trisilol cyclohexyl cage-like polysilsesquioxane (CAS: 4115-83-7), trisilol cyclopentyl cage-like polysilsesquioxane (CAS: 135225-24-0), disilol isobutyl cage-like polysilsesquioxane (CAS: 307531-90-4), trisilol ethyl cage-like polysilsesquioxane, and tetrasilanol phenyl cage-like polysilsesquioxane. After polymerization, the stirring time of the product solution system, the auxiliaries, and the solvent mixture slurry or mixed solution is 10-120 min.

[0017] The polyolefin elastomer of the present invention has a copolymer monomer weight ratio of 10-60 wt%, an ω-olefin-based halosilane weight ratio of 0.0005-2 wt%, and an additive weight ratio of 0.001-5 wt%.

[0018] The molar ratio of the co-catalyst to the main catalyst described in this invention (the ratio of the central metal Al in the co-catalyst to the transition metal M in the main catalyst, or the ratio of the central non-metal B in the co-catalyst to the transition metal M in the main catalyst) is 1.05-1000.

[0019] The polyolefin elastomer of this invention has a weight-average molecular weight of 10,000-500,000 g / mol, a molecular weight distribution of 1.5-10, and a density of 0.856-0.900 g / cm³. 3 Furthermore, the weight-average molecular weight can be adjusted by introducing hydrogen during the preparation process.

[0020] According to the polyolefin elastomer features of the present invention, the polyolefin elastomer can be widely used in the preparation of films, fibers, toughening materials, pipes, profiles, photovoltaic films, wires and cables, foamed products and modified engineering plastic products.

[0021] Compared with the prior art, the beneficial effects of this application are as follows:

[0022] (1) By adding appropriate amounts of ω-olefinic halosilane and auxiliaries containing at least two -OH hydroxyl groups, at least two -NH2 amino groups, or at least two -NH imino groups during the preparation process, Si-O or Si-N bond structures can be introduced into the polymer backbone through the reaction of Si-Cl or Si-Br bonds with OH bonds and the reaction of Si-Cl or Si-Br bonds with NH bonds. In this case, some copolymer segments of ethylene or propylene with the comonomer serve as long-branched side chains. The content of long-branched structures in the polymer can be controlled by adjusting the amount of ω-olefinic halosilane and auxiliaries added.

[0023] (2) By introducing Si-O or Si-N bond structures into the polymer backbone, the easy degradation characteristics of Si-O or Si-N bond structures can be utilized to achieve molecular chain breakage and efficient recycling of polyolefin elastomers through hydrolysis or alcoholysis reactions in acidic or alkaline solutions.

[0024] (3) The introduction of long branched structure can effectively improve melt strength and tensile modulus, improve shear thinning characteristics, improve melt fluidity and processing stability. The above characteristics can be controlled according to the amount of long branched content, and polyolefin elastomer products with different physical properties and performance can be developed to meet the requirements of films, foams, fibers, reinforcement and toughening, photovoltaic films, wires and cables and other fields.

[0025] (4) By introducing Si-O or Si-N bond structures into the polymer backbone, additives can be effectively inserted into polymer segments, improving the thermal stability of polyolefin elastomer materials. In addition, the introduction of Si-O or Si-N polar groups can improve the compatibility of polyolefin elastomer materials with inorganic fillers, thereby improving the properties of composite materials, such as impact resistance, adhesion, and biocompatibility, and broadening the application range of this polyolefin elastomer material in blending modification. Attached Figure Description

[0026] Figure 1 This is the 1H NMR spectrum of polyolefin elastomer A.

[0027] Figure 2 These are rheological curves of polyolefin elastomers A and E. Detailed Implementation

[0028] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0029] The following methods are used to test the structure or properties of the polyolefin elastomers produced in the embodiments described above:

[0030] High-temperature gel permeation chromatography (GPC) is used to test the weight-average molecular weight and molecular weight distribution of polyolefin elastomers.

[0031] Gradient density meters are used to test the density of polyolefin elastomers.

[0032] Carbon nuclear magnetic resonance (CMR) spectroscopy is used to analyze the insertion rate of copolymer monomers in polyolefin elastomers, while hydrogen nuclear magnetic resonance (HMR) spectroscopy is used to analyze the content of SiO or Si-N bonds in polyolefin elastomers.

[0033] Rheological sweep frequency testing is used to analyze the relationship between the complex viscosity and shear frequency of polyolefin elastomers.

[0034] Example 1

[0035] 2 L of n-hexane, 1.2 L of 1-hexene, 6 μmol of tris(pentafluorophenyl)borane, 2000 μmol of methylaluminoxane, 5 μmol of geometry-restricted catalyst (CAS: 135072-61-6), and 1 mmol of 6-heptenylmethyldichlorosilane were added sequentially to a 5 L anhydrous and oxygen-free reactor. After the polymerization temperature reached 150 °C, ethylene gas was introduced to the set polymerization pressure of 35 bar to initiate the polymerization reaction. After 25 min of polymerization, a mixed slurry of octa(aminophenyltrioxosilane) and n-hexane (containing 3 mmol of the auxiliary agent) was introduced into the product solution. After stirring for 60 min, a solution rich in polyolefin elastomer A was obtained. Subsequently, devolatilization and granulation steps were performed to obtain granular polyolefin elastomer A. The analytical characterization results of polyolefin elastomer A are shown in Table 1.

[0036] Example 2

[0037] 1.8 L of cyclohexane, 1.6 L of 1-octene, 6 μmol of tris(pentafluorophenyl)borane, 1200 μmol of modified methylaluminoxane, 5 μmol of geometry-restricted catalyst (CAS: 135072-62-7), and 0.8 mmol of 5-hexenylethyldichlorosilane were added sequentially to a 5 L reactor under anhydrous and oxygen-free conditions. After the polymerization temperature reached 170 °C, ethylene gas was introduced to the set polymerization pressure of 40 bar to initiate the polymerization reaction. After 100 min of polymerization, a mixed slurry of octamaleic acid cage-type silsesquioxane and cyclohexane (containing 5 mmol of the additive) was introduced into the product solution. After stirring for 20 min, a solution rich in polyolefin elastomer B was obtained. Subsequently, devolatilization and granulation steps were performed to obtain granular polyolefin elastomer B. The analytical characterization results of polyolefin elastomer B are shown in Table 1.

[0038] Example 3

[0039] 2.5 L of isoparaffin Isopar E, 1.2 L of 1-heptene, 6 μmol of tris(pentafluorophenyl)borane, 5 μmol of metallocene catalyst (CAS: 132510-07-7), and 1.5 mmol of 5-hexenylethyldichlorosilane were added sequentially to a 5 L anhydrous and oxygen-free reactor. After the polymerization temperature reached 170 °C, ethylene gas was introduced to the set polymerization pressure of 25 bar to initiate the polymerization reaction. After 80 min of polymerization, a mixed slurry of the auxiliary agent trisilyl cyclopentyl cage-like polysilsesquioxane (CAS: 135225-24-0) and isoparaffin Isopar E (containing 2 mmol of the auxiliary agent) was introduced into the product solution. After stirring for 100 min, a solution rich in polyolefin elastomer C was obtained. Subsequently, devolatilization and granulation steps were performed to obtain granular polyolefin elastomer C. The analytical characterization results of polyolefin elastomer C are shown in Table 1.

[0040] Example 4

[0041] 1.8 L of n-hexane, 1.6 L of 1-hexene, 6 μmol of tris(pentafluorophenyl)borane, 1200 μmol of modified methylaluminoxane, 5 μmol of metallocene catalyst (CAS: 132510-07-7), and 0.8 mmol of 5-hexenylethyldichlorosilane were added sequentially to a 5 L anhydrous and oxygen-free reactor. After the polymerization temperature reached 105 °C, propylene gas was introduced to the set polymerization pressure of 11 bar to initiate the polymerization reaction. After 50 min of polymerization, a slurry containing 2 mmol of the additive disiloyl isobutyl cage-like polysilsesquioxane (CAS: 307531-90-4) and n-hexane was introduced into the product solution. After stirring for 40 min, a solution rich in polyolefin elastomer D was obtained. Subsequently, devolatilization and granulation steps were performed to obtain granular polyolefin elastomer D. The analytical characterization results of polyolefin elastomer D are shown in Table 1.

[0042] Comparative Example 1

[0043] 2 L of n-hexane, 1.2 L of 1-hexene, 6 μmol of tris(pentafluorophenyl)borane, 2000 μmol of methylaluminoxane, and 5 μmol of geometry-restricted catalyst (CAS: 135072-61-6) were sequentially added to a 5 L anhydrous and oxygen-free reactor. After the polymerization temperature reached 150 °C, ethylene gas was introduced to a set polymerization pressure of 35 bar to initiate the polymerization reaction. After 25 min of polymerization, the product solution was subjected to devolatilization and granulation to obtain granular polyolefin elastomer E. The analytical characterization results of polyolefin elastomer E are shown in Table 1.

[0044] Table 1 - AE Characterization Results of Polyolefin Elastomers

[0045]

[0046]

[0047] From Table 1, Figure 1 and Figure 2 It is evident that introducing Si-O bonds into the molecular chain of polyolefin elastomer A effectively introduces long-branched structures, thereby improving the melt strength and shear thinning properties of polyolefin elastomer A. This is beneficial for improving melt flowability, processing stability, and the tensile modulus of the elastomer. In contrast, the molecular chain of polyolefin elastomer E in Comparative Example 1 does not contain Si-O bonds or long-branched structures; it only possesses the short-branched structures of conventional polyolefin elastomers, namely the short-branched structures introduced by the comonomer. Consequently, its melt strength and tensile modulus are lower, and its shear thinning properties are not significant. Furthermore, the content of long-branched structures in the polymer can be controlled by adjusting the amount of ω-olefin-based halosilane and additives. This allows for the development of polyolefin elastomer products with different physical and performance characteristics to meet the requirements of fields such as films, foams, fibers, reinforcement and toughening, photovoltaic films, and wires and cables.

[0048] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A polyolefin elastomer material, characterized in that, The polyolefin elastomer molecular chain contains Si-O or Si-N bond structures, and the molar ratio of Si-O or Si-N bonds to C-C bonds in the polyolefin elastomer is 0.0001%-1%; the preparation method of the polyolefin elastomer includes the following steps: Solvent, comonomer, cocatalyst, main catalyst, and ω-olefin-based halosilane are added to an anhydrous and oxygen-free reactor. After the polymerization temperature rises to the set value, ethylene or propylene gas is introduced to the set polymerization pressure to start the polymerization reaction. After the polymerization is completed, a mixed slurry or mixed solution of additives and solvent is introduced into the product solution system. After stirring, a solution rich in the polyolefin elastomer is obtained. Subsequently, devolatilization and granulation are carried out to obtain granular polyolefin elastomer. The additive is selected from cage-like polysilsesquioxanes, and the additive contains at least 2 -OH hydroxyl groups, at least 2 -NH2 amino groups, or at least 2 -NH imino groups; the cage-like polysilsesquioxane additive is selected from one or more of octa(3-hydroxy-3-methylbutyldimethylsiloxane), octa(aminophenyltrioxane), N-phenylamino-cage-like polysilsesquioxane, octamaleic acid cage-like polysilsesquioxane, trisilol cyclohexyl cage-like polysilsesquioxane, trisilol cyclopentyl cage-like polysilsesquioxane, disilol isobutyl cage-like polysilsesquioxane, trisilol ethyl cage-like polysilsesquioxane, and tetrasilanol phenyl cage-like polysilsesquioxane.

2. The polyolefin elastomer material according to claim 1, characterized in that, The Si-O bond is formed by the reaction of the Si-Cl bond or Si-Br bond with the OH bond, and the Si-N bond is formed by the reaction of the Si-Cl bond or Si-Br bond with the NH bond.

3. The polyolefin elastomer material according to claim 1, characterized in that, The solvent is selected from one or more of n-pentane, isopentane, n-hexane, cyclohexane, n-heptane, 2-methylhexane, 3-methylhexane, isoparaffin Isopar C, and isoparaffin Isopar E; the comonomer is selected from one or more of 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene; the main catalyst is selected from one or more of bridged metallocene catalysts, non-bridged metallocene catalysts, and restricted geometry catalysts; the cocatalyst is selected from one or more of methylaluminoxane, modified methylaluminoxane, tris(pentafluorophenyl)borane, borate, triethylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum.

4. The polyolefin elastomer material according to claim 1, characterized in that, The ω-olefin halosilane has 1, 2, or 3 Si-X bonds, where X is Cl or Br, and the olefin group is a straight-chain or branched α-olefin group with 1-50 carbon atoms.

5. The polyolefin elastomer material according to claim 4, characterized in that, The ω-olefinic halosilane is selected from 9-decenyldimethylchlorosilane, 9-decenylmethyldichlorosilane, 9-decenyltrichlorosilane, 9-decenyldiethylchlorosilane, 9-decenylethyldichlorosilane, 8-nonenyldimethylchlorosilane, 8-nonenylmethyldichlorosilane, 8-nonenyltrichlorosilane, 8-nonenyldiethylchlorosilane, 8-nonenylethyldichlorosilane, 7-octenyldimethylchlorosilane, 7-octenylmethyldichlorosilane, 7-octenyltrichlorosilane, 7-octenyldiethylchlorosilane, 7-octenylethyldichlorosilane, 6-heptenyldimethylchlorosilane, 6-heptenylmethyldichlorosilane, 6- One or more of the following: heptenyltrichlorosilane, 6-heptenyldiethylchlorosilane, 6-heptenylethyldichlorosilane, 5-hexenyldimethylchlorosilane, 5-hexenylmethyldichlorosilane, 5-hexenyltrichlorosilane, 5-hexenyldiethylchlorosilane, 5-hexenylethyldichlorosilane, 4-pentenyldimethylchlorosilane, 4-pentenylmethyldichlorosilane, 4-pentenyltrichlorosilane, 4-pentenyldiethylchlorosilane, 4-pentenylethyldichlorosilane, 3-butenyldimethylchlorosilane, 3-butenylmethyldichlorosilane, 3-butenyltrichlorosilane, 3-butenyldiethylchlorosilane, and 3-butenylethyldichlorosilane.

6. The polyolefin elastomer material according to claim 1, characterized in that, The polymerization reaction time is 5-180 min, the polymerization temperature is 100-180 ℃, the polymerization pressure is 10-60 bar, the content of the additive in the mixed slurry or mixed solution of the additive and solvent is 1-50 wt%, and the stirring time of the product solution system and the mixed slurry or mixed solution of the additive and solvent after polymerization is 10-120 min.

7. The polyolefin elastomer material according to claim 1, characterized in that, The polyolefin elastomer contains 10-60 wt% copolymer monomers, 0.0005-2 wt% ω-olefin-based halosilanes, and 0.001-5 wt% additives.

8. The polyolefin elastomer material according to claim 3, characterized in that, The molar ratio of the co-catalyst to the main catalyst is between 1.05 and 1000, calculated by the ratio of the central metal Al in the co-catalyst to the transition metal M in the main catalyst, or by the ratio of the central non-metal B in the co-catalyst to the transition metal M in the main catalyst.

9. The polyolefin elastomer material according to any one of claims 1-8, wherein the weight-average molecular weight of the polyolefin elastomer is in the range of 10,000-500,000 g / mol, the molecular weight distribution is in the range of 1.5-10, and the density is in the range of 0.856-0.900 g / cm³. 3 Furthermore, the weight-average molecular weight can be adjusted by introducing hydrogen during the preparation process.

10. The application of the polyolefin elastomer material according to claim 1 or 2 in the preparation of films, fibers, toughening materials, pipes, profiles, photovoltaic films, wires and cables, foamed products and modified engineering plastic products.

Images