CN116063596A - High-pressure polyethylene for fruit string bag and preparation method and application thereof - Google Patents
High-pressure polyethylene for fruit string bag and preparation method and application thereof Download PDFInfo
- Publication number
- CN116063596A CN116063596A CN202111276392.0A CN202111276392A CN116063596A CN 116063596 A CN116063596 A CN 116063596A CN 202111276392 A CN202111276392 A CN 202111276392A CN 116063596 A CN116063596 A CN 116063596A
- Authority
- CN
- China
- Prior art keywords
- polymerization reaction
- pressure
- organic peroxide
- polyethylene
- ethylene
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- -1 polyethylene Polymers 0.000 title claims abstract description 69
- 239000004698 Polyethylene Substances 0.000 title claims abstract description 56
- 229920000573 polyethylene Polymers 0.000 title claims abstract description 56
- 238000002360 preparation method Methods 0.000 title claims abstract description 32
- 235000013399 edible fruits Nutrition 0.000 title claims abstract description 11
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 42
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims abstract description 34
- 239000005977 Ethylene Substances 0.000 claims abstract description 34
- 150000001451 organic peroxides Chemical class 0.000 claims abstract description 34
- 230000000977 initiatory effect Effects 0.000 claims abstract description 30
- 239000002954 polymerization reaction product Substances 0.000 claims abstract description 22
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 15
- 238000000926 separation method Methods 0.000 claims abstract description 4
- 238000005469 granulation Methods 0.000 claims abstract description 3
- 230000003179 granulation Effects 0.000 claims abstract description 3
- WYKYCHHWIJXDAO-UHFFFAOYSA-N tert-butyl 2-ethylhexaneperoxoate Chemical compound CCCCC(CC)C(=O)OOC(C)(C)C WYKYCHHWIJXDAO-UHFFFAOYSA-N 0.000 claims abstract description 3
- 239000000047 product Substances 0.000 claims description 23
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 14
- 239000002904 solvent Substances 0.000 claims description 12
- 239000003999 initiator Substances 0.000 claims description 11
- 239000000243 solution Substances 0.000 claims description 10
- XSZYESUNPWGWFQ-UHFFFAOYSA-N 1-(2-hydroperoxypropan-2-yl)-4-methylcyclohexane Chemical compound CC1CCC(C(C)(C)OO)CC1 XSZYESUNPWGWFQ-UHFFFAOYSA-N 0.000 claims description 9
- 239000001294 propane Substances 0.000 claims description 8
- FVQMJJQUGGVLEP-UHFFFAOYSA-N (2-methylpropan-2-yl)oxy 2-ethylhexaneperoxoate Chemical compound CCCCC(CC)C(=O)OOOC(C)(C)C FVQMJJQUGGVLEP-UHFFFAOYSA-N 0.000 claims description 6
- CNPVJWYWYZMPDS-UHFFFAOYSA-N 2-methyldecane Chemical compound CCCCCCCCC(C)C CNPVJWYWYZMPDS-UHFFFAOYSA-N 0.000 claims description 6
- GTJOHISYCKPIMT-UHFFFAOYSA-N 2-methylundecane Chemical compound CCCCCCCCCC(C)C GTJOHISYCKPIMT-UHFFFAOYSA-N 0.000 claims description 6
- SGVYKUFIHHTIFL-UHFFFAOYSA-N Isobutylhexyl Natural products CCCCCCCC(C)C SGVYKUFIHHTIFL-UHFFFAOYSA-N 0.000 claims description 6
- 238000009826 distribution Methods 0.000 claims description 6
- 239000007924 injection Substances 0.000 claims description 6
- 238000002347 injection Methods 0.000 claims description 6
- VKPSKYDESGTTFR-UHFFFAOYSA-N isododecane Natural products CC(C)(C)CC(C)CC(C)(C)C VKPSKYDESGTTFR-UHFFFAOYSA-N 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 238000007599 discharging Methods 0.000 claims description 5
- LSXWFXONGKSEMY-UHFFFAOYSA-N di-tert-butyl peroxide Chemical compound CC(C)(C)OOC(C)(C)C LSXWFXONGKSEMY-UHFFFAOYSA-N 0.000 claims description 4
- SNRUBQQJIBEYMU-UHFFFAOYSA-N dodecane Chemical compound CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- 229940094933 n-dodecane Drugs 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 3
- 239000003607 modifier Substances 0.000 claims description 3
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 claims description 2
- 150000001335 aliphatic alkanes Chemical class 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N hydrogen peroxide Substances OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 abstract description 3
- 238000005265 energy consumption Methods 0.000 abstract description 2
- QUPCNWFFTANZPX-UHFFFAOYSA-N hydrogen peroxide;1-methyl-4-propan-2-ylcyclohexane Chemical compound OO.CC(C)C1CCC(C)CC1 QUPCNWFFTANZPX-UHFFFAOYSA-N 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 11
- 230000035484 reaction time Effects 0.000 description 11
- 238000005187 foaming Methods 0.000 description 6
- PBKONEOXTCPAFI-UHFFFAOYSA-N 1,2,4-trichlorobenzene Chemical compound ClC1=CC=C(Cl)C(Cl)=C1 PBKONEOXTCPAFI-UHFFFAOYSA-N 0.000 description 3
- 238000001746 injection moulding Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- SHZIWNPUGXLXDT-UHFFFAOYSA-N caproic acid ethyl ester Natural products CCCCCC(=O)OCC SHZIWNPUGXLXDT-UHFFFAOYSA-N 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000006261 foam material Substances 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 229920001684 low density polyethylene Polymers 0.000 description 2
- 239000004702 low-density polyethylene Substances 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 239000012778 molding material Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 235000015096 spirit Nutrition 0.000 description 2
- HBHVBOUUMCIGMG-UHFFFAOYSA-N 2,6-Dibutyl-p-cresol Natural products CCCCC1=CC(O)=CC(CCCC)=C1O HBHVBOUUMCIGMG-UHFFFAOYSA-N 0.000 description 1
- LZFZQYNTEZSWCP-UHFFFAOYSA-N 2,6-dibutyl-4-methylphenol Chemical compound CCCCC1=CC(C)=CC(CCCC)=C1O LZFZQYNTEZSWCP-UHFFFAOYSA-N 0.000 description 1
- 244000241235 Citrullus lanatus Species 0.000 description 1
- 235000012828 Citrullus lanatus var citroides Nutrition 0.000 description 1
- 241000723267 Diospyros Species 0.000 description 1
- 235000011511 Diospyros Nutrition 0.000 description 1
- 244000141359 Malus pumila Species 0.000 description 1
- 239000004594 Masterbatch (MB) Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 235000021016 apples Nutrition 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 238000005227 gel permeation chromatography Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F110/02—Ethene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
- C08L23/06—Polyethene
Abstract
The invention relates to high-pressure polyethylene for fruit net bags, and a preparation method and application thereof, wherein the preparation method comprises the following steps: s100, carrying out a first polymerization reaction on ethylene in the presence of a regulator and a first organic peroxide initiation system to obtain a first polymerization reaction product containing unreacted ethylene, wherein the first organic peroxide initiation system comprises tert-butyl pivalate peroxide and tert-butyl peroxy-2-ethylhexanoate, the temperature of the first polymerization reaction is 320-340 ℃, and the pressure is 255-260 MPa; s200, carrying out a second polymerization reaction in the presence of a second organic peroxide initiating system to obtain a second polymerization reaction product, wherein the second organic peroxide initiating system comprises peroxyacetic acid, hydrogen peroxide di-tert-butyl and hydrogen peroxide p-menthane, the temperature of the second polymerization reaction is 331-335 ℃, and the pressure is 240-255 MPa; s300, carrying out depressurization, separation and granulation on a second polymerization reaction product to obtain the high-pressure polyethylene. The method is simple, easy to operate and low in energy consumption.
Description
Technical Field
The invention relates to the technical field of polymer synthesis, in particular to high-pressure polyethylene for fruit net bags and a preparation method and application thereof.
Background
The low density polyethylene is suitable for various molding processes of thermoplastic plastics, for example, can be used for film products, injection molding products, extrusion foaming products and can also be used as master batch carrier resin. The polyethylene foam product has good physical and chemical properties, and is gradually becoming a variety with various products, large production and wide application range. And because the polyethylene has light capacity, small heat conductivity coefficient, large range of sound insulation, heat insulation and buffering physical properties, the polyethylene foam material has been developed rapidly for several years, is mainly applied to producing coiled materials and sheets for shoes, air-conditioning heat preservation, anisotropic packaging, toys for children, sports goods and the like, and is deeply favored by manufacturers.
In recent years, along with the improvement of the living standard of people, the use amount of the fruit net cover is increased year by year, and fruits suitable for the plastic net cover are apples, oranges, persimmons, watermelons and the like. The polyethylene foam material can be used as raw material of fruit net cover because it is nontoxic and can be contacted with food. However, the fruit string bag foaming resin special for the low-density polyethylene does not exist in China, and general materials are generally used for foaming in the market, so that the foaming rate is low and the rebound resilience is poor.
Disclosure of Invention
In view of the above, the invention aims at overcoming the defects existing in the prior art, and provides the high-pressure polyethylene for the fruit string bag, and the preparation method and application thereof.
The aim of the invention is achieved by the following technical scheme.
In a first aspect, the invention provides a method for preparing high pressure polyethylene for fruit string bags, wherein the method comprises the steps of:
s100, carrying out a first polymerization reaction on ethylene in the presence of a regulator and a first organic peroxide initiating system to obtain a first polymerization reaction product containing unreacted ethylene, wherein the first organic peroxide initiating system comprises tert-butyl pivalate peroxide and tert-butyl peroxy-2-ethylhexanoate, and the temperature of the first polymerization reaction is 320-340 ℃ and the pressure is 250-260 MPa;
s200, carrying out a second polymerization reaction on a first polymerization reaction product containing unreacted ethylene in the presence of a second organic peroxide initiation system to obtain a second polymerization reaction product, wherein the second organic peroxide initiation system comprises acetic peroxide, di-tert-butyl hydroperoxide and p-menthane hydroperoxide, the temperature of the second polymerization reaction is 331-335 ℃, and the pressure is 240-255 MPa;
s300, carrying out depressurization, separation and granulation on the second polymerization reaction product to obtain the high-pressure polyethylene.
In the present invention, the melt index of the high-pressure polyethylene can be adjusted by the adjusting agent.
According to the preparation method provided by the invention, the regulator in the step S100 is C2-C6 alkane, preferably propane.
In some embodiments, in step S100, the modifier is used in an amount of 150.+ -.25 ppm based on the weight of ethylene added.
According to the preparation method provided by the invention, the first organic peroxide initiating system is added in the form of a solution in step S100, and the solvent in the solution of the first organic peroxide initiating system is preferably solvent oil A. Examples of mineral spirits a suitable for use in the present invention include, but are not limited to: isoaxalane, isododecane and n-dodecane. In some embodiments, the solvent oil a is selected from at least one of isoundecane and isododecane.
According to the preparation method provided by the invention, in the step S100, the amount of the tert-butyl pivalate peroxide in the first organic peroxide initiating system is 0.5 to 0.75 weight percent, preferably 0.5 to 0.65 weight percent, and more preferably 0.5 to 0.6 weight percent based on the weight of the added ethylene; the amount of t-butyl peroxy-2-ethylhexanoate is 0.87 to 1.2 wt%, preferably 0.95 to 1.2 wt%, more preferably 0.95 to 1.0 wt%.
According to the preparation method provided by the invention, the time of the first polymerization reaction in the step S100 is 8-9 seconds.
According to the preparation method provided by the invention, the first polymerization reaction in the step S100 is performed in the presence of air. In some embodiments, the amount of air used in step S100 is from 4 to 8m, based on a high pressure polyethylene yield of 22.8t/h 3 /h。
The preparation method provided by the invention, wherein the step S100 comprises the following steps:
s101, mixing ethylene with flash ethylene from a primary compressor and/or a secondary compressor, compressing the mixture to 250-260 MPa through the primary compressor, mixing the mixture with circulating materials, and entering the secondary compressor to compress the mixture to 265-270 MPa, and adding the regulator from an inlet of the primary compressor;
s102, feeding the mixed gas flow compressed to 265-270 MPa by a secondary compressor into a first reactor, preheating the first reactor, adding a first organic peroxide initiating system from a first initiator injection port, adding air from an inlet of the secondary compressor, heating to 320-340 ℃, preferably 330-340 ℃, and carrying out first polymerization under the pressure of 250-260 MPa, preferably 250-255 MPa.
In some embodiments, the first reactor is preheated to 120-160 ℃, e.g., 140 ℃ in step S102.
According to the preparation method provided by the invention, the second organic peroxide initiation system is added in the form of a solution in the step S200, and the solvent in the solution of the second organic peroxide initiation system is preferably solvent oil B. Examples of mineral spirits B suitable for use in the present invention include, but are not limited to: isoaundecane, isododecane and n-dodecane.
In some embodiments, the amount of peroxyacetic acid in the second organic peroxide initiating system is from 0.4 to 0.6 weight percent, preferably from 0.5 to 0.56 weight percent, based on the weight of the first polymerization product; the amount of di-tert-butyl hydroperoxide used is from 0.8 to 1.2% by weight, preferably from 0.9 to 1.0% by weight; the amount of p-menthane hydroperoxide is 0.4 to 0.6 wt.%, preferably 0.5 to 0.6 wt.%.
According to the preparation method provided by the invention, the time of the second polymerization reaction in the step S200 is 13-15 seconds.
The preparation method provided by the invention, wherein the step S200 comprises the following steps:
s201, feeding a first polymerization reaction product containing unreacted ethylene into a second reactor, adding a second organic peroxide initiating system from a second initiator injection port, and carrying out second polymerization reaction at the temperature of 331-335 ℃ and the pressure of 240-250 MPa.
According to the preparation method provided by the invention, the step S200 further comprises the following steps: prior to step S201, the first polymerization product containing unreacted ethylene is cooled, preferably to 30-45 ℃.
The preparation method provided by the invention, wherein the step S300 comprises the following steps:
s301, cooling the second polymerization reaction product to 30-45 ℃ in a second reactor, reducing the pressure by a discharge valve at an outlet, discharging the reduced pressure into a high-pressure separator, and separating gas from product materials to obtain ethylene gas and polyethylene products;
s302, melting the polyethylene product obtained in the step S301, sending the melted polyethylene product into a low-pressure separator for separating gas from product materials, obtaining ethylene gas and a polyethylene product, and granulating to obtain high-pressure polyethylene.
The preparation method provided by the invention has the advantage that the single-pass conversion rate of the preparation method is generally 22-25%.
The preparation method provided by the invention, wherein the method further comprises the step of sending ethylene gas from the high-pressure separator and/or the low-pressure separator as circulating materials to the step S101.
The preparation method provided by the invention is implemented by adopting a tubular high-pressure polymerization process device. The present invention is not particularly limited to a tubular high pressure polymerization process apparatus, and any tubular high pressure polymerization process apparatus known in the art may be employed.
In a second aspect, the present invention also provides a high pressure polyethylene produced by the above production process.
The high-pressure polyethylene provided by the invention, wherein the melt index of the high-pressure polyethylene at the temperature of 190 ℃ and the load of 2.16Kg is 4-10 g/10min, preferably 5-8 g/10min, as measured according to GB/T3682.1-2000; and/or the density of the high pressure polyethylene is 0.916-0.924 g/cm 3 Preferably 0.918 to 0.922g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The molecular weight distribution index (Mw/Mn) of the high-pressure polyethylene is 4 to 9, preferably 5 to 6.
The high-pressure polyethylene provided by the invention has a tensile strength of more than 10MPa, preferably more than 11MPa; the tensile strain at break is greater than 300%, preferably greater than 450%.
In a third aspect, the invention also provides application of the high-pressure polyethylene in preparation of a foaming string bag.
The invention has the following advantages:
(1) In the invention, the high-pressure polyethylene is prepared by adjusting the polymerization process, particularly selecting an initiator system, controlling the polymerization pressure and the polymerization temperature and further controlling the selection and the addition amount of an adjusting agent according to the requirement, and the method has important significance for researching and developing special polyethylene materials;
(2) The method is simple, easy to operate and low in energy consumption, and the single-pass conversion rate of the reaction is 22-25%; the produced high-pressure polyethylene has narrow molecular weight distribution and high elongation at break, and is suitable for the production of foaming net bags.
Detailed Description
The invention is further illustrated below in connection with specific examples, which are not to be construed as limiting the invention in any way.
Example 1
(1) Ethylene was mixed with flash ethylene from the primary and secondary compressors, compressed to 255MPa by the primary compressor, mixed with recycle material and fed into the secondary compressor inlet, and the regulator propane was added at 150ppm based on the weight of ethylene added, from the primary compressor inlet tank to obtain a mixed gas stream.
(2) Secondary compressor handle mixingThe gas stream was compressed to 269.1MPa and then fed into the front of a first reactor preheated to 140 ℃ and fed from a first initiator injection port with an isoundecane solution of a first organic peroxide initiating system wherein the amount of t-butyl pivalate peroxide was 0.5 wt% and the amount of t-butyl peroxy-2-ethylhexanoate initiator was 0.95 wt% based on the weight of ethylene added; at a hexene addition of 100m 3 And (h) adding air from the inlet of the secondary compressor, raising the temperature to 330 ℃, and carrying out a first polymerization reaction under 225MPa for 8-9 seconds to obtain a first polymerization reaction product containing unreacted ethylene.
(3) The first polymerization reaction product containing unreacted ethylene is cooled to 60 ℃, is fed into a second reactor, and is added with an isoundecane solution of a second organic peroxide initiating system from a second initiator injection port, wherein the dosage of peroxyacetic acid is 0.5 wt%, the dosage of hydrogen peroxide di-tert-butyl is 0.9 wt% and the dosage of hydrogen peroxide p-menthane is 0.5 wt%, based on the weight of the first polymerization reaction product, the second polymerization reaction is carried out, the reaction temperature is 331 ℃, the pressure is 240MPa, and the reaction time is 13-15 seconds.
(4) Cooling the second polymerization reaction product to 70 ℃ in the second reactor, reducing the pressure by a discharging valve at the outlet, discharging the second polymerization reaction product into a high-pressure separator for separating gas from materials, and obtaining ethylene gas and polyethylene products. And melting the obtained polyethylene product, sending the melted polyethylene product into a low-pressure separator for gas and material separation to obtain ethylene gas and a polyethylene product, and granulating to obtain high-pressure polyethylene.
The single pass conversion of the preparation process of example 1 is typically 24.3%. Ethylene gas from the high pressure separator and the low pressure separator is sent as recycle to step (1).
Example 2
High pressure polyethylene was prepared in substantially the same manner as in example 1, except that:
(a) The amount of regulator propane used in step (1) was 165ppm.
(b) In the step (2), the amount of t-butyl pivalate peroxide used was 0.6% by weight, the amount of t-butyl peroxy-2-ethylhexanoate initiator used was 0.99% by weight, and air was introduced from the inlet of the secondary compressor, and the conditions for the first polymerization reaction were as follows: the temperature is 340 ℃, the pressure is 260MPa, and the reaction time is 8-9 seconds.
(c) The amount of peracetic acid in the step (3) was 0.56 wt%, the amount of di-t-butyl hydroperoxide was 0.98 wt%, the amount of p-menthane hydroperoxide was 0.45 wt%, and the conditions for the second polymerization reaction were as follows: the temperature is 331 ℃, the pressure is 245MPa, and the reaction time is 13-15 seconds.
The single pass conversion of the preparation process of example 2 is typically 24.6%.
Example 3
High pressure polyethylene was prepared in substantially the same manner as in example 1, except that:
(a) The amount of regulator propane used in step (1) was 140ppm.
(b) In the step (2), the amount of t-butyl pivalate peroxide as an organic peroxide and 1.2% of 2-ethyl hexanoate peroxide as an initiator was 0.62% by weight, and air was introduced from the inlet of the secondary compressor, and the conditions for the first polymerization were as follows: the temperature is 330 ℃, the pressure is 260MPa, and the reaction time is 8-9 seconds.
(c) The amount of peracetic acid in the step (3) was 0.53 wt%, the amount of di-t-butyl hydroperoxide was 0.98 wt%, the amount of p-menthane hydroperoxide was 0.60 wt%, and the conditions for the second polymerization reaction were as follows: the temperature is 335 ℃, the pressure is 245MPa, and the reaction time is 13-15 seconds.
The single pass conversion of the preparation process of example 3 is typically 24.8%.
Example 4
High pressure polyethylene was prepared in substantially the same manner as in example 1, except that:
(a) The amount of regulator propane used in step (1) was 135ppm.
(b) In the step (2), the amount of t-butyl pivalate peroxide as the organic peroxide and 1.0% of 2-ethyl hexanoate peroxide as the initiator was 0.57% by weight, and air was introduced from the inlet of the secondary compressor, and the conditions for the first polymerization were as follows: the temperature is 330 ℃, the pressure is 260MPa, and the reaction time is 8-9 seconds.
(c) The amount of peracetic acid in the step (3) was 0.55 wt%, the amount of di-t-butyl hydroperoxide was 1.0 wt%, the amount of p-menthane hydroperoxide was 0.60 wt%, and the conditions for the second polymerization reaction were as follows: the temperature is 335 ℃, the pressure is 245MPa, and the reaction time is 13-15 seconds.
The single pass conversion of the preparation process of example 4 is typically 23.9%.
Example 5
High pressure polyethylene was prepared in substantially the same manner as in example 1, except that:
(a) The amount of regulator propane used in step (1) was 158ppm.
(b) In the step (2), the amount of t-butyl pivalate peroxide, which is an organic peroxide, was 0.6 wt% and the amount of t-butyl peroxy-2-ethylhexanoate was 0.96 wt%, air was added from the inlet of the secondary compressor, and the conditions for the first polymerization were as follows: the temperature is 330 ℃, the pressure is 250MPa, and the reaction time is 8-9 seconds.
(c) The amount of peracetic acid in the step (3) was 0.55 wt%, the amount of di-t-butyl hydroperoxide was 1.0 wt%, the amount of p-menthane hydroperoxide was 0.60 wt%, and the conditions for the second polymerization reaction were as follows: the temperature is 333 ℃, the pressure is 255MPa, and the reaction time is 13-15 seconds.
The single pass conversion of the preparation process of example 5 is typically 24.4%.
Example 6
High pressure polyethylene was prepared in substantially the same manner as in example 1, except that:
(a) The amount of regulator propane used in step (1) was 175ppm.
(b) In the step (2), the amount of t-butyl pivalate peroxide, which is an organic peroxide, was 0.65 wt% and the amount of t-butyl peroxy-2-ethylhexanoate was 0.96 wt%, and air was added from the inlet of the secondary compressor, and the conditions for the first polymerization were as follows: the temperature is 330 ℃, the pressure is 250MPa, and the reaction time is 8-9 seconds.
(c) The amount of peracetic acid in the step (3) was 0.55 wt%, the amount of di-t-butyl hydroperoxide was 1.0 wt%, the amount of p-menthane hydroperoxide was 0.60 wt%, and the conditions for the second polymerization reaction were as follows: the reaction temperature is 333 ℃, the pressure is 255MPa, and the reaction time is 13-15 seconds.
The single pass conversion of the preparation process of example 6 is typically 24.7%.
Performance testing
In the present invention, the following test standards and methods were used to test high pressure polyethylene.
Melt mass flow rate: according to GB/T3682.1-2000, the conditions are: 190 ℃,2.16Kg; in g/10min.
Density: according to GB/T1033.2-2010 measurement, the conditions are: the temperature is 23 ℃; unit kg/m 3 。
Tensile yield strength: measured according to ASTM D638-2010, units, MPa.
Elongation at break: measured according to ASTM D638-2010,%.
Molecular weight distribution (Mw/Mn): gel permeation chromatography is adopted, the solvent and the mobile phase are 1,2, 4-trichlorobenzene (containing 0.025 weight percent of antioxidant 2, 6-dibutyl-p-cresol), the column temperature is 150 ℃, the flow rate is 1.0ml/min, and the narrow-distribution polystyrene standard sample is adopted for universal calibration.
The properties of the high pressure polyethylenes prepared in examples 1 to 6 are shown in Table 1.
Table 1 properties of the high pressure polyethylenes prepared in examples 1 to 6
As can be seen from Table 1, the high-pressure polyethylene injection molding material prepared by the preparation method of the invention has narrow molecular weight distribution, high melt index and low density, and is suitable for the production of injection molding materials.
It should be noted that the above-described embodiments are only for explaining the present invention and do not constitute any limitation of the present invention. The invention has been described with reference to exemplary embodiments, but it is understood that the words which have been used are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as defined in the appended claims, and the invention may be modified without departing from the scope and spirit of the invention. Although the invention is described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all other means and applications which perform the same function.
Claims (10)
1. The preparation method of the high-pressure polyethylene for the fruit string bag comprises the following steps of:
s100, carrying out a first polymerization reaction on ethylene in the presence of a regulator and a first organic peroxide initiating system to obtain a first polymerization reaction product containing unreacted ethylene, wherein the first organic peroxide initiating system comprises tert-butyl pivalate peroxide and tert-butyl peroxy-2-ethylhexanoate, and the temperature of the first polymerization reaction is 320-340 ℃ and the pressure is 250-260 MPa;
s200, carrying out a second polymerization reaction on a first polymerization reaction product containing unreacted ethylene in the presence of a second organic peroxide initiation system to obtain a second polymerization reaction product, wherein the second organic peroxide initiation system comprises acetic peroxide, di-tert-butyl hydroperoxide and p-menthane hydroperoxide, the temperature of the second polymerization reaction is 331-335 ℃, and the pressure is 240-255 MPa;
s300, carrying out depressurization, separation and granulation on the second polymerization reaction product to obtain the high-pressure polyethylene.
2. The method of claim 1, wherein the modifier in step S100 is a C2-C6 alkane, preferably propane;
preferably, in step S100, the modifier is used in an amount of 150.+ -.25 ppm based on the weight of ethylene added.
3. The preparation method according to claim 1 or 2, wherein the first organic peroxide initiating system is added in the form of a solution in step S100;
preferably, the solvent in the solution of the first organic peroxide initiation system in step S100 is solvent oil a, where the solvent oil a is at least one selected from the group consisting of isoundecane, isododecane and n-dodecane, and preferably at least one selected from the group consisting of isoundecane and isododecane;
preferably, in step S100, the amount of t-butyl pivalate peroxide in the first organic peroxide initiating system is from 0.5 to 0.75 weight percent, preferably from 0.5 to 0.65 weight percent, more preferably from 0.5 to 0.6 weight percent, based on the weight of ethylene added; the amount of t-butyl peroxy-2-ethylhexanoate is 0.87 to 1.2 wt%, preferably 0.95 to 1.2 wt%, more preferably 0.95 to 1.0 wt%.
4. A production method according to any one of claims 1 to 3, wherein the time of the first polymerization reaction in step S100 is 8 to 9 seconds; and/or the number of the groups of groups,
the first polymerization in step S100 is carried out in the presence of air at a high pressure polyethylene yield of 22.8t/h and a hexene loading of 100m 3 The air quantity in step S100 is preferably 4-8 m in terms of per hour 3 /h。
5. The method according to any one of claims 1 to 4, wherein step S100 comprises:
s101, mixing ethylene with flash ethylene from a primary compressor and/or a secondary compressor, compressing the mixture to 250-260 MPa through the primary compressor, mixing the mixture with circulating materials, and entering the secondary compressor to compress the mixture to 265-270 MPa, and adding the regulator from an inlet of the primary compressor;
s102, feeding the mixed gas flow compressed to 265-270 MPa by a secondary compressor into a first reactor, preheating the first reactor, adding a first organic peroxide initiating system from a first initiator injection port, adding air from an inlet of the secondary compressor, heating to 320-340 ℃, preferably 330-340 ℃, and carrying out first polymerization under the pressure of 250-260 MPa, preferably 250-255 MPa.
6. The process according to any one of claims 1 to 5, wherein the second organic peroxide initiating system in step S200 is added in solution;
preferably, the solvent in the solution of the second organic peroxide initiating system in the step S200 is solvent oil B, where the solvent oil B is at least one selected from the group consisting of isoundecane, isododecane and n-dodecane;
preferably, the amount of peroxyacetic acid in the second organic peroxide initiating system is from 0.4 to 0.6 wt%, preferably from 0.5 to 0.56 wt%, based on the weight of the first polymerization reaction product; the amount of di-tert-butyl hydroperoxide used is from 0.8 to 1.2% by weight, preferably from 0.9 to 1.0% by weight; the amount of p-menthane hydroperoxide is 0.4 to 0.6 wt.%, preferably 0.5 to 0.6 wt.%.
7. The method according to any one of claims 1 to 6, wherein step S200 comprises:
s201, feeding a first polymerization reaction product containing unreacted ethylene into a second reactor, adding a second organic peroxide initiating system from a second initiator injection port, and carrying out a second polymerization reaction at a temperature of 331-335 ℃ and a pressure of 240-250 MPa;
preferably, step S200 further comprises: prior to step S201, the first polymerization reaction product containing unreacted ethylene is cooled, preferably to 30-45 ℃;
preferably, the second polymerization reaction in step S200 takes 13 to 15 seconds.
8. The method according to any one of claims 1 to 7, wherein step S300 comprises:
s301, cooling the second polymerization reaction product to 30-45 ℃ in a second reactor. Reducing the pressure by a discharging valve at the outlet, discharging the reduced pressure into a high-pressure separator for separating gas from product materials to obtain ethylene gas and polyethylene products;
s302, melting the polyethylene product obtained in the step S301, sending the melted polyethylene product into a low-pressure separator for separating gas from product materials, obtaining ethylene gas and a polyethylene product, and granulating to obtain high-pressure polyethylene.
9. A high pressure polyethylene produced by the production process according to any one of claims 1 to 8;
preferably, the high pressure polyethylene has a melt index of 4 to 10g/10min, preferably 5 to 8g/10min, at a temperature of 190 ℃ and a load of 2.16Kg, as measured according to GB/T3682.1-2000; and/or the density of the high pressure polyethylene is 0.916-0.924 g/cm 3 Preferably 0.918 to 0.922g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The molecular weight distribution index (Mw/Mn) of the high-pressure polyethylene is 4 to 9, preferably 5 to 6.
10. Use of the high pressure polyethylene of claim 9 for the preparation of a foamed string bag.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111276392.0A CN116063596A (en) | 2021-10-29 | 2021-10-29 | High-pressure polyethylene for fruit string bag and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111276392.0A CN116063596A (en) | 2021-10-29 | 2021-10-29 | High-pressure polyethylene for fruit string bag and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116063596A true CN116063596A (en) | 2023-05-05 |
Family
ID=86171986
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111276392.0A Pending CN116063596A (en) | 2021-10-29 | 2021-10-29 | High-pressure polyethylene for fruit string bag and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116063596A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104817654A (en) * | 2015-04-16 | 2015-08-05 | 浙江大学 | Method and device for producing low density polyethylene |
| CN105153333A (en) * | 2015-10-14 | 2015-12-16 | 华北石油管理局总医院 | Preparation method of polyvinyl for medicine packaging |
| CN105585647A (en) * | 2014-10-20 | 2016-05-18 | 中国石油化工股份有限公司 | Preparation method of polyethylene special material for vehicle decorative non-woven fabric back glue |
| CN111100233A (en) * | 2018-10-25 | 2020-05-05 | 中国石油化工股份有限公司 | Synthesis method of high-pressure polyethylene for repackaging film |
-
2021
- 2021-10-29 CN CN202111276392.0A patent/CN116063596A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105585647A (en) * | 2014-10-20 | 2016-05-18 | 中国石油化工股份有限公司 | Preparation method of polyethylene special material for vehicle decorative non-woven fabric back glue |
| CN104817654A (en) * | 2015-04-16 | 2015-08-05 | 浙江大学 | Method and device for producing low density polyethylene |
| CN105153333A (en) * | 2015-10-14 | 2015-12-16 | 华北石油管理局总医院 | Preparation method of polyvinyl for medicine packaging |
| CN111100233A (en) * | 2018-10-25 | 2020-05-05 | 中国石油化工股份有限公司 | Synthesis method of high-pressure polyethylene for repackaging film |
Non-Patent Citations (1)
| Title |
|---|
| 《化工工艺学》: "《化工工艺学》", vol. 5, 重庆大学出版社, pages: 199 - 200 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1137019C (en) | Process for preparation of foamed beads of propylene polymers | |
| CN107849161B (en) | Process for the high-pressure repolymerization of ethylenically unsaturated monomers in a tubular reactor | |
| CN111378062B (en) | Industrial production method of high-melt-strength polypropylene resin | |
| JP6093604B2 (en) | Polypropylene resin expanded particles and molded articles thereof | |
| KR101672618B1 (en) | Method for manufacturing Ethylene Vinyl Acetate Copolymer and Ethylene Vinyl Acetate Copolymer manufactured by the same | |
| CN105705553A (en) | Modification of polyamides | |
| CN111100233B (en) | Synthetic method of high-pressure polyethylene for repackaging film | |
| CN116063596A (en) | High-pressure polyethylene for fruit string bag and preparation method and application thereof | |
| US9840571B2 (en) | Inert stripping of volatile organic compounds from polymer melts | |
| US6894126B2 (en) | Method for producing ethylene homopolymers and copolymers by means of radical high pressure polymerization | |
| US20230212337A1 (en) | Process for producing ethylene homo- and copolymers | |
| US8192677B2 (en) | Core/shell polymer and fluoropolymer blending blow molding and blown film process | |
| KR20190067812A (en) | Method for producing functionalized ethylene polymer | |
| CN116063603A (en) | High-pressure polyethylene injection molding material and preparation method thereof | |
| EP1423466B1 (en) | Process for preparing cross-linked polyolefins | |
| US4082910A (en) | Multi-stage isolation of high pressure polyethylene | |
| CN112812404A (en) | Special low-density polyethylene resin composition for transparent film material and preparation method of transparent film | |
| CN114075308B (en) | Ethylene-vinyl acetate copolymer resin, and molded body and film comprising ethylene-vinyl acetate copolymer resin | |
| CN107001737B (en) | Process for preparing modified ethylene polymers using hydrocarbon initiators | |
| Sipaut et al. | The effect of different peroxide on LDPE foam properties in the presence of polyfunctional monomers | |
| US3153029A (en) | Terminal modified polymeric materials | |
| WO2001066632A1 (en) | Process for preparing cross-linked polyolefins | |
| CN108976345B (en) | Method for preparing high-melt-strength polypropylene through solid-phase reaction | |
| CN115232233B (en) | Method for preparing low-density polyethylene by tubular method and low-density polyethylene | |
| CN114395161B (en) | Foamable thermoplastic polyurethane elastomer and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |