Modified TPO (thermoplastic polyolefin) material as well as preparation method and application thereof

Abstract

The invention relates to a modified TPO material as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly, grafting a functional monomer (PDC) to a TPO macromolecular chain by adopting a chemical grafting mode to prepare a TPO-g-PDC master batch, then carrying out melt blending on the TPO master batch and an unmodified TPO raw material to prepare a B-TPO material, and finally, further improving the surface activity of the B-TPO material by adopting a plasma surface treatment technology. The bonding performance of the TPO is remarkably improved while the excellent performance of the TPO is not influenced. A low-cost, high-efficiency and lossless modification strategy is provided for the tackifying problem of the TPO material, and the application of the TPO material in the fields of buildings, automobiles, photovoltaics and the like is expanded.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials, and particularly relates to a modified TPO material, a preparation method thereof and an application thereof. Background Art

[0002] TPO material (Thermoplastic Olefin Elastomer) is composed of ethylene propylene diene monomer (EPDM) and polypropylene (PP), and has good flexibility, aging resistance, acid and alkali resistance and recyclability, and is widely used in high-end industries such as construction, automobiles, and photovoltaic.

[0003] However, since both EPDM and PP are non-polar polymers with low surface energy, it is difficult to bond the TPO material during use, and problems such as difficult bonding and easy debonding occur when used together with materials such as rubber and plastic, which severely limit the practical application of the TPO material. Summary of the Invention

[0004] The purpose of the present invention is to provide a modified TPO material, a preparation method thereof and an application thereof. The key of the invention lies in combining the chemical grafting of TPO and the plasma surface treatment method, thereby greatly improving the bonding strength between the modified TPO material and other plastic or rubber materials. The summary of the invention includes three parts. First, the solution suspension grafting method is adopted to chemically graft TPO by controlling the dosage ratio of the grafting monomer PDC, the initiator and the TPO material, and the grafting masterbatch TPO-g-PDC is prepared by controlling the temperature. Second, a mixer is used to prepare the B-TPO material containing different grafting masterbatches by controlling the dosage ratio of TPO-g-PDC and ungrafted TPO, and then a hot pressing device is used to form the B-TPO material into a sheet, a plate or a film material by controlling the temperature and pressure. Third, a plasma radio frequency sputtering machine is used to perform surface treatment on the B-TPO sample by controlling the type of working gas, the power and the treatment time to prepare the M-TPO modified material with synergistic adhesion enhancement. The present invention synergistically improves the polarity of TPO by chemical grafting and plasma surface treatment, greatly enhances the bonding performance, and does not change the excellent properties of the TPO material itself.

[0005] In order to achieve the above purpose, the technical solution of the present invention is:

[0006] The present invention provides a preparation method of a modified TPO material. The preparation method includes: introducing a PDC graft side chain onto the TPO macromolecular chain by solution suspension grafting to obtain a TPO graft masterbatch, denoted as TPO-g-PDC; melt-blending the TPO-g-PDC and ungrafted TPO to obtain a blend-modified TPO material, denoted as B-TPO, and forming the B-TPO into a sheet, plate or film; then performing plasma surface treatment on the B-TPO using a plasma radio frequency sputtering machine to obtain the modified TPO material, denoted as M-TPO.

[0007] Further, the preparation method includes the following steps: Step 1, preparation of TPO-g-PDC: Disperse TPO pellets in a solvent, add a PDC functional monomer and an initiator, and then transfer to a reaction kettle with a nitrogen environment, heat to a certain temperature and stir for pre-swelling, and perform a solution suspension grafting reaction when the system is stable; the product is washed and purified with the solvent to remove residual monomers and homopolymers of physical blending to obtain the TPO-g-PDC; wherein, the temperature of pre-swelling is 50-90 °C and the time is 1-2 h; the polymerization temperature of the solution suspension grafting reaction is 60-90 °C and the time is 1-8 h; Step 2, preparation of B-TPO: (1) Add TPO-g-PDC and ungrafted TPO to a mixer and melt until evenly mixed to obtain a B-TPO material; wherein, the operating parameters of the melting are: temperature 220-260 °C and time 30-60 min; (2) Put the B-TPO material into a hot press to form a sheet, plate or film material, and cool to room temperature to obtain the B-TPO sample; Step 3, preparation of M-TPO: After the B-TPO sample is further heat-pretreated, place it under a plasma radio frequency sputtering machine for plasma surface treatment to obtain M-TPO; wherein, the heat pretreatment temperature is 60-80 °C and the time is 8-10 min; the working gas for the plasma surface treatment is one or more of air, oxygen, argon and nitrogen; the power is 100-300 W and the time is 10-100 s.

[0008] Further, the dosage of each component in Step 1 is in parts by mass: the TPO is 100 parts, the PDC functional monomer is 3-15 parts, and the initiator is 0.1-0.5 parts.

[0009] Further, in Step 1, the TPO includes one or more of the grades CNMs, C200F, Q300F, CA10A, CA12A, CA60A, 903T; the solvent is one or more of water, acetone, ethanol, benzene, chloroform.

[0010] Further, in Step 1, the PDC functional monomer includes one or more of acrylic acid, glycidyl methacrylate, acrylamide, dimethylacrylamide, vinyl alcohol, methyl vinyl ether, methyl acrylate, methyl methacrylate, and maleic anhydride.

[0011] Further, in Step 1, the initiator is selected from any one or a combination of several of oil-soluble initiators and water-soluble initiators; wherein, the oil-soluble initiator is selected from at least one of azo initiators and peroxide initiators; optionally, the azo initiators include azobisisobutyronitrile, azobisisoheptonitrile, azobisisopentanenitrile, azodicyclohexylmethyl cyanide, and dimethyl azodisobutyrate; the peroxide initiators include dicumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, etc.; the water-soluble initiators include persulfates, redox initiation systems, azobis(isobutyramidine) dihydrochloride, azobis(2-methylpropionamidine) dihydrochloride, azobis(2-methylpropionamidine), and azodicyanovaleric acid, etc.

[0012] Further, the dosages of the components in Step 2 are as follows in parts by mass: 5-30 parts of TPO-g-PDC and 95-70 parts of TPO.

[0013] Further, in Step 2, the operating parameters of the flat vulcanization method specifically adopted in the hot press are as follows: the first stage: temperature 220 - 250 °C, pressure 0 MPa, time 8 - 10 min; the second stage: temperature 220 - 280 °C, pressure 0.5 - 1.0 MPa, time 8 - 10 s; the third stage: room temperature, pressure 0 MPa, time 10 min.

[0014] The present invention also provides a modified TPO material prepared by the preparation method of the modified TPO material as described above.

[0015] The present invention also provides the application of the modified TPO material as described above in the fields of construction, automobiles, and photovoltaics.

[0016] The present invention has the following advantages:

[0017] 1. The TPO adopted in the present invention has a rich variety and excellent comprehensive performance. At the same time, the chemical grafting and plasma treatment processes are mature, with high modification efficiency and high practicability, providing new ideas for the modification of TPO.

[0018] 2. The present invention mixes the chemically grafted TPO masterbatch with the TPO raw material to explore the tackifying performance while controlling the cost, having practical application value.

[0019] 3. The present invention adopts the synergistic effect of PDC chemical grafting and plasma surface treatment to increase the polarity of TPO. Without damaging the original performance of TPO, its surface is rich in oxygen-containing functional groups, laying a foundation for enhancing the bonding performance of TPO.

[0020] 4. After the B-TPO is prepared in the present invention, its bonding performance is tested, and it is improved by about 1.9 to 2.5 times compared with the pure TPO material.

[0021] 5. After the M-TPO is prepared in the present invention, its bonding performance is tested, and it is improved by about 1.4 to 3.0 times compared with the pure TPO material.

[0022] Combined with the above properties, the M-TPO described in the present invention has excellent bonding performance. Description of the Drawings

[0023] Figure 1 is the infrared spectrogram of TPO, TPO-g-MAH masterbatch and B-TPO material in the embodiment of the present invention;

[0024] Figure 2 is the XPS test chart of the M-TPO prepared in the embodiment of the present invention;

[0025] Figure 3 is the SEM chart and EDS chart of the M-TPO prepared in the embodiment of the present invention;

[0026] Figure 4 is the bonding strength test of the B-TPO material prepared in the embodiment of the present invention;

[0027] Figure 5 is the bonding strength test of the M-TPO material prepared in the embodiment of the present invention. Detailed Embodiments

[0028] In view of the technical problems existing in the prior art, the present invention discloses a method for modifying and tackifying TPO materials by combining chemical grafting and plasma treatment technologies. Without affecting the advantages of TPO itself, the bonding performance between TPO and other plastics and rubbers is improved. The method mainly includes the following steps: (1) Using the solution suspension grafting method, introduce PDC graft side chains on the TPO macromolecular chain to prepare TPO graft masterbatch (TPO-g-PDC); (2) Melt-blend a certain proportion of TPO-g-PDC graft masterbatch and ungrafted TPO material to prepare a uniform blend-modified TPO material (B-TPO), and form it into sheets or plates or film materials through a press; (3) Use a plasma radio frequency sputtering machine to perform plasma surface treatment on the above B-TPO material to prepare a modified TPO material (M-TPO) with a synergistic tackifying effect.

[0029] By introducing a certain amount of TPO graft masterbatch containing polar groups into non-polar TPO materials, without damaging the excellent mechanical and thermal properties of the TPO materials themselves, the adhesion performance of the modified TPO materials is effectively enhanced, enriching the practical application value of the TPO materials, which can be used in the fields of building waterproofing, automotive parts, photovoltaics, etc.

[0030] The grafted substance PDC generally refers to a class of chemical substances that contain both double bonds and polar groups in the molecule. A typical example is acrylic acid (containing a double bond and a polar carboxyl group). PDC substances that can undergo chemical grafting include, but are not limited to, acrylate monomers, acrylic acids and their derivatives, enamine monomers, enol monomers, maleic anhydride, etc. Its molecular structure characteristics are: there are both double bonds and polar groups in the molecular structure. Among them, the double bond can be opened under the stimulation of force and heat to generate active free radicals, and the free radicals can react with the H atoms on the TPO macromolecular chain, so that PDC is grafted onto the macromolecular chain; at the same time, the introduced polar groups can effectively improve the polarity and adhesion performance of the TPO macromolecules. Usually, the double bond of a compound is composed of a σ bond and a π bond. The electron cloud of the π bond is not as concentrated on the line connecting the two atomic nuclei as the σ bond, but is distributed on both sides of the molecular plane. The electron cloud is relatively dispersed and is easily affected by external factors, with relatively high reactivity. And the polarity of a molecule is jointly determined by the polarity of the chemical bond and the spatial configuration of the molecule. For a molecule containing a double bond, if the atoms connected at both ends of the double bond are different, due to the different abilities of different atoms to attract electrons, the electron cloud will be unevenly distributed on the double bond, resulting in polarity. TPO is a non-polar polymer, and PDC is a polar graft monomer. When PDC is chemically grafted onto the TPO macromolecular chain, the prepared grafted product has good adhesion to both polar and non-polar materials.

[0031] Plasma surface treatment technology is a technology that uses plasma to physically or chemically modify the surface of materials. Its principle is that active particles (such as ions, electrons, free radicals) in high-energy plasma act on the material surface to change the surface chemical composition or microstructure, thereby improving its adhesion performance. It has the advantages of being fast, efficient, and safe. Without affecting the comprehensive performance of the material itself, it can improve the film roughness. At the same time, the active particles in the plasma can introduce new active functional groups on the material surface. With different types of gases used and treatment processes, hydroxyl groups (-OH), ester groups (-C=O), amino groups (-NH 2 )), fluoro groups (-CF 3 , -CF 2 -) etc. can be introduced on the surface. The introduction of these functional groups can improve the polarity and chemical activity of the material surface, thereby improving the compatibility and binding force of the material with other substances, and further improving its adhesion performance.

[0032] In summary, the present invention proposes that the bonding performance of TPO materials can be synergistically enhanced through PDC chemical grafting and plasma surface treatment. This method does not affect the excellent comprehensive performance of TPO materials themselves, and has low cost and high efficiency, enabling batch production processing.

[0033] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments. However, the content of the present invention is not limited to the following embodiments. The measurement units of the following components are all parts by mass.

[0034] Example 1:

[0035] A method for enhancing the viscosity of TPO materials.

[0036] Step 1: Preparation of TPO-g-DMMA masterbatch:

[0037] Select TPO pellets of model C200F as raw materials and disperse them in water. Add 100 parts of TPO and 6 parts of dimethylacrylamide (DMMA) to the reaction kettle under a nitrogen atmosphere. After mixing evenly, add 0.1 part of benzoyl peroxide. Then raise the temperature to 70 °C and stir vigorously for 1 hour to complete pre-swelling. After the system temperature stabilizes, react continuously for 2 hours. The product is washed and purified with ethanol to remove the residual monomers and homopolymers of physical blending, and the TPO-g-DMMA masterbatch is prepared.

[0038] Step 2: Preparation of B-TPO material:

[0039] (1) Add 5 parts of TPO-g-DMAA masterbatch and 95 parts of TPO raw materials to a two-roll mixer, control the temperature at 230 °C, and melt and mix for 40 min to prepare B-TPO material.

[0040] (2) Put the B-TPO material into a flat vulcanizing machine and set the temperature at 250 °C. First, heat it for 8 min without pressure to fully melt the material, then increase the pressure to 0.5 MPa, keep the pressure for 8 s and then take it out, place it on a cooling layer, and apply pressure to cool it to prepare B-TPO profiles.

[0041] Step 3: Preparation of M-TPO:

[0042] Pre-treat the B-TPO profiles at 60 °C for 8 min, and then put them into a JS-450A type plasma radio frequency sputtering device for surface treatment for 20 s to prepare M-TPO materials. The working gas of the sputtering device is air and the power is 100 W.

[0043] Example 2:

[0044] A method for enhancing the viscosity of TPO materials.

[0045] Step 1: Preparation of TPO-g-MMA masterbatch:

[0046] Select the TPO pellets of model CA10A as raw materials and disperse them in water. Add 100 parts of TPO and 8 parts of methyl methacrylate (MMA) into the reaction kettle under a nitrogen atmosphere. After mixing evenly, add 0.3 part of azobisisobutyramidine hydrochloride. Then raise the temperature to 80 °C and stir vigorously for 1 hour to complete pre-swelling. After the system temperature is stable, react continuously for 4 hours. The product is washed and purified with anhydrous acetone to remove the residual monomers and homopolymers of physical blending, and the TPO-g-MMA masterbatch is prepared.

[0047] Step 2: Preparation of B-TPO material:

[0048] (1) Add 10 parts of TPO-g-MMA masterbatch and 90 parts of TPO raw materials into a two-roll mixer, control the temperature at 240 °C, and melt and mix for 50 min to prepare the B-TPO material.

[0049] (2) Put the B-TPO material into a flat vulcanizing machine and set the temperature at 250 °C. First, heat it for 9 min without pressure to fully melt the material, then raise the pressure to 0.7 MPa, keep the pressure for 9 s and then take it out, place it on a cooling layer, and apply pressure to cool it to prepare the B-TPO profile.

[0050] Step 3: Preparation of M-TPO:

[0051] Pretreat the M-TPO profile at 70 °C for 9 min, put it into a JS-450A type plasma radio frequency sputtering device for surface treatment for 30 s to prepare the M-TPO material. The working gas of the sputtering device is nitrogen and the power is 200 W.

[0052] Example 3:

[0053] A method for tackifying and modifying TPO materials.

[0054] Step 1: Preparation of TPO-g-MAH masterbatch:

[0055] Select the TPO pellets of model CA60A as raw materials and disperse them in water. Add 100 parts of TPO and 10 parts of maleic anhydride (MAH) into the reaction kettle under a nitrogen atmosphere. After mixing evenly, add 0.5 part of benzoyl peroxide. Then raise the temperature to 90 °C and stir vigorously for 2 hours to complete pre-swelling. After the system temperature is stable, react continuously for 8 hours. The product is washed and purified with chloroform to remove the residual monomers and homopolymers of physical blending, and the TPO-g-MAH masterbatch is prepared.

[0056] Step 2: Preparation of B-TPO material:

[0057] (1) Add 15 parts of TPO-g-MAH masterbatch and 85 parts of TPO raw material into a two-roll mixer, control the temperature at 250 °C, and melt and mix for 60 min to prepare B-TPO material.

[0058] (2) Put the B-TPO material into a flat vulcanizer, set the temperature at 250 °C; first heat it for 10 min without pressure to fully melt the material, then increase the pressure to 0.9 MPa, keep the pressure for 10 s and then take it out, place it on a cooling layer, apply pressure for cooling to prepare B-TPO profiles.

[0059] Step 3: Preparation of M-TPO:

[0060] Pre-treat the B-TPO profiles at 80 °C for 10 min, put them into a JS-450A type plasma radio frequency sputtering device for surface treatment for 40 s to prepare M-TPO material. The working gas of the sputtering device is air and the power is 300 W.

[0061] In this example, the infrared spectra of TPO, TPO-g-MAH masterbatch and B-TPO material are as Figure 1 shown. It can be seen from the analysis of the spectra that the materials all show a symmetric stretching vibration characteristic peak corresponding to the carbonyl C=O group near 1730 cm -1 , indicating that MAH has been successfully grafted onto the TPO molecular chain.

[0062] In this example, the XPS test of M-TPO is as Figure 2 shown; among them, (a) is the full spectrum, (b) is the C1s fine spectrum, (c) is the N1s fine spectrum, (d) is the O1s fine spectrum. It can be seen from Figure 2 this that after plasma treatment, the content of O element in the material increases significantly, and a significant characteristic peak of N element appears. At the same time, the binding energies of C-O-C and C-NH 2 functional groups appear, and the characteristic peak in O 1s also increases significantly, confirming that the M-TPO material has richer oxygen-containing functional groups after plasma treatment.

[0063] In this example, the SEM and EDS (C element and O element) tests of M-TPO are as Figure 3 shown; among them, (a) is TPO, (b) is 5 wt%, (c) is 10 wt%, (d) is 15 wt%. It can be seen from Figure 3 this that the surface of the material is relatively smooth, and the distributions of C and O elements are uniform, indicating that the prepared material has good uniformity.

[0064] In this example, the bond strength test of B-TPO material is as Figure 4As shown in the figure; among them, (a) is a schematic diagram of the bond strength test, (b) is the bond strength change curve of TPO and B-TPO materials, (c) is the bond strength of TPO and B-TPO materials, and (d) is a photo of the fracture surface after stretching of TPO and B-TPO materials. From Figure 4 It can be seen that when the masterbatch content is 15 wt%, the bond strength is 6.5 MPa, which is 276% higher than that of pure TPO material.

[0065] In this embodiment, the bond strength test of M-TPO material is as Figure 5 shown; among them, (a) is the bond strength change curve of TPO and M-TPO materials, and (b) is a photo of the fracture surface after stretching of TPO and M-TPO materials. From Figure 5 It can be seen that when the masterbatch content is 15 wt%, the bond strength is 7.0 MPa, which is 297% higher than that of pure TPO material.

[0066] The upper and lower limit values and interval values of each process parameter (such as temperature, time, etc.) listed in the present invention, and each specific raw material (such as TPO, PDC, initiator) can all implement the present invention, and the embodiments are not listed one by one here. Although the technical solutions of the present invention have been described in detail in the above embodiments, the technical solutions of the present invention are not limited to the above embodiments. Without departing from the spirit and purpose of the present invention, equivalent changes or modifications made to the content of the patent application scope of the present invention shall fall within the technical scope of the present invention.

Claims

1. A method for preparing a modified TPO material, characterized in that: The preparation method comprises: introducing a PDC graft side chain onto a TPO macromolecular chain by a solution suspension grafting method to obtain a TPO grafted masterbatch, which is recorded as TPO-g-PDC; melt-blending the TPO-g-PDC and ungrafted TPO to obtain a blended modified TPO material, which is recorded as B-TPO, and making the B-TPO into a sheet, a plate or a film; and then performing plasma surface treatment on the B-TPO by a plasma radio frequency sputtering machine to obtain the modified TPO material, which is recorded as M-TPO.

2. The method for preparing the modified TPO material according to claim 1, characterized in that: The preparation method comprises the following steps: Step 1, preparation of TPO-g-PDC: The TPO pellets are dispersed in a solvent, and after adding PDC functional monomers and initiators, they are transferred to a reactor with a nitrogen environment, heated to a temperature where they are stirred for pre-swelling, and a solution suspension grafting reaction is performed when the system is stable; the product is washed and purified by a solvent to remove residual monomers and homopolymers of physical blending, thereby obtaining the TPO-g-PDC; wherein the pre-swelling temperature is 50-90°C and the time is 1-2 hours; the polymerization temperature of the solution suspension grafting reaction is 60-90°C and the time is 1-8 hours; Step 2, preparation of B-TPO: (1) adding TPO-g-PDC and ungrafted TPO into a mixer and melting them until they are uniformly mixed to obtain a B-TPO material; wherein the melting operation parameters are: temperature 220-260° C., time 30-60 min; (2) placing the B-TPO material into a hot press to form a sheet, plate or film material, and cooling it to room temperature to obtain the B-TPO sample; Step 3, preparation of M-TPO: After the B-TPO sample is subjected to heat pretreatment, it is placed in a plasma radio frequency sputtering machine for plasma surface treatment to obtain M-TPO; wherein the heat pretreatment temperature is 60-80°C and the time is 8-10 minutes; the working gas for the plasma surface treatment is one or more of air, oxygen, argon and nitrogen; the power is 100-300W and the time is 10-100s.

3. The method for preparing the modified TPO material according to claim 2, characterized in that: The amounts of the components in step 1 are calculated in parts by mass as follows: 100 parts of TPO, 3 to 15 parts of PDC functional monomers, and 0.1 to 0.5 parts of initiators.

4. The method for preparing the modified TPO material according to claim 2, characterized in that: In step 1, the TPO includes one or more of the brands CNMs, C200F, Q300F, CA10A, CA12A, CA60A, and 903T; and the solvent is one or more of water, acetone, ethanol, benzene, and chloroform.

5. The method for preparing the modified TPO material according to claim 2, characterized in that: In step 1, the PDC functional monomers include one or more of acrylic acid, glycidyl methacrylate, acrylic amine, dimethacrylic amine, vinyl alcohol, methyl vinyl ether, methyl acrylate, methyl methacrylate, and maleic anhydride.

6. The method for preparing the modified TPO material according to claim 2, characterized in that: In step 1, the initiator is selected from any one or a combination of oil-soluble initiators and water-soluble initiators; wherein the oil-soluble initiator is selected from at least one of an azo initiator and a peroxide initiator; Optionally, the azo initiator includes azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovaleronitrile, azobiscyclohexylcarbonitrile and dimethyl azobisisobutyrate; The peroxide initiator includes dicumyl peroxide, benzoyl peroxide, and di-tert-butyl peroxide; The water-soluble initiator includes persulfate, redox initiation system, azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, azobisisobutylimidazoline and azobiscyanovaleric acid.

7. The method for preparing the modified TPO material according to claim 2, characterized in that: The amounts of the components in step 2 are as follows: 5-30 parts of TPO-g-PDC and 95-70 parts of TPO, in parts by mass.

8. The method for preparing the modified TPO material according to claim 2, characterized in that: In step 2, the operating parameters of the plate vulcanization method specifically used in the hot press are: first stage: temperature 220-250°C, pressure 0MPa, time 8-10min; The second stage: temperature 220-280°C, pressure 0.5-1.0 MPa, time 8-10 s; the third stage: room temperature, pressure 0 MPa, time 10 min.

9. The modified TPO material obtained by the method for preparing the modified TPO material according to any one of claims 1 to 8.

10. Application of the modified TPO material according to claim 9 in the fields of construction, automobile and photovoltaic.

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