Degradable plastic film and preparation method thereof

Abstract

The invention relates to the technical field of plastic films, and particularly discloses a degradable plastic film and a preparation method thereof. The degradable plastic film is prepared from the following components in parts by mass: 100 parts of polypropylene resin; 3.5 to 4.5 parts of color master batch; 1.8 to 2.2 parts of an anti-blocking agent; 0.08 to 0.12 part of a gloss conditioning agent; 40 to 50 parts of a degradable filler; 0.5 to 0.8 part of a degradation agent; the degradable filler is obtained by modifying polylactic acid fibers with a modifying solution; the modified liquid is formed by compounding dimethylaminopropyl methacrylamide, 2-ethylhexyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol. The preparation method has the advantage that the prepared plastic film is high in strength and good in degradability.

Description

Technical Field

[0001] The invention relates to the field of plastic films, in particular to a degradable plastic film and a preparation method thereof. Background Art

[0002] With the increasing awareness of environmental protection and the rapid development of the medical industry, biodegradable plastics have become a popular choice to replace traditional plastics. Currently, biodegradable plastics on the market mainly include polylactic acid (PLA), polyhydroxyalkanoates (PHA), polycaprolactone (PCL), etc. However, these biodegradable materials have low strength. After being made into thin films, the defects of insufficient strength are further magnified due to the thin film thickness. It is difficult to meet the packaging needs of the medical industry by simply using biodegradable plastics to prepare plastic films.

[0003] The use of polypropylene to prepare plastic film can produce a film with higher strength, but polypropylene has the defect of being difficult to degrade and it is difficult to meet the concept of environmental protection. Therefore, there is still room for improvement. Summary of the invention

[0004] In order to prepare a plastic film with high strength and good degradability, the present application provides a degradable plastic film and a preparation method thereof.

[0005] In a first aspect, the present application provides a degradable plastic film, which adopts the following technical solution: A degradable plastic film is prepared from the following components in parts by weight: 100 parts of polypropylene resin; Masterbatch 3.5-4.5 parts; 1.8-2.2 parts of opening agent; Gloss regulator 0.08-0.12 parts; 40-50 parts of degradable filler; Degradation agent 0.5-0.8 parts; The degradable filler is obtained by modifying polylactic acid fiber with a modifying liquid; The modified liquid is a compound of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol.

[0006] By adopting the above technical solution, the degradation of polypropylene can be accelerated by adding a degradation agent, and the amount of polypropylene can be reduced by adding a degradable filler, thereby further accelerating the degradation speed, so that the degradable plastic film can automatically rot and dissolve within a specified time (6 months to 1 year), thereby achieving an environmental protection effect.

[0007] The degradable filler is obtained by modifying polylactic acid fiber with a modifying liquid. After the polylactic acid fiber is modified with a modifying liquid prepared by compounding dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol, the strength of the composite material obtained by melt blending the polylactic acid fiber and polypropylene is significantly improved, so that the plastic film can still have high strength under the premise of reducing the amount of polypropylene and adding a large amount of degradable filler, which can well meet the needs of medical packaging, thereby making the degradable plastic film have the advantages of high strength and fast degradation rate.

[0008] By specifically selecting polylactic acid fibers, the polylactic acid fibers can be better dispersed evenly when mixed with polypropylene resins. Moreover, since the polylactic acid fibers have a larger specific surface area, the modification effect is better, thereby achieving a better effect of improving the strength of the degradable plastic film.

[0009] Preferably, in the modified liquid, the mass ratio of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether, and ethanol is 10-12:8-10:3-5:7-9:100.

[0010] By adopting the above technical scheme and specifically selecting the mass ratio of methylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol, the effect of the modified polylactic acid fiber is better, the strength of the degradable plastic film is better improved, and the degradable plastic film better meets the needs of medical packaging and has better quality.

[0011] Preferably, the method for preparing the degradable filler comprises the following steps: Step 1), dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether, and ethanol are mixed to prepare a modified liquid; Step 2), putting the polylactic acid fiber into the modified liquid, keeping the temperature at 55-65°C, soaking for 6-8 hours, filtering out and drying to obtain the degradable filler.

[0012] By adopting the above technical solution, the modification is more complete through immersion at a constant temperature of 55-65℃ for 6-8h, and the modification effect on polylactic acid fiber is better. The addition of a large amount of degradable filler to polypropylene is not likely to cause a decrease in strength, so that the plastic film maintains a high strength.

[0013] Preferably, in step 2), the mass ratio of the polylactic acid fiber to the modified liquid is 1:1-2.

[0014] By adopting the above technical solution and specifically selecting the mass ratio of polylactic acid fiber and modifying liquid, the modification is more sufficient and the degradable filler can better maintain the high strength of the plastic film.

[0015] Preferably, the opening agent is erucamide.

[0016] By adopting the above technical solution and specifically selecting erucic acid amide, the performance of the plastic film is improved and the quality is better.

[0017] Preferably, the gloss regulator is white mineral oil.

[0018] By adopting the above technical solution and specifically selecting white mineral oil, the plastic film is made more glossy and of better quality.

[0019] Preferably, the degradation agent is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane.

[0020] By adopting the above technical scheme and specifically selecting 3.3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, the effect of promoting the degradation of polypropylene is better, the addition amount is less, the cost is effectively controlled, and the quality of the obtained plastic film is better.

[0021] In a second aspect, the present application provides a method for preparing a degradable plastic film, using the following technical solution: A method for preparing the above-mentioned degradable plastic film comprises the following steps: Step 01), polypropylene resin, masterbatch, anti-blocking agent, gloss regulator, degradable filler, and degradation agent are mixed to obtain a premix; Step 02), extruding and blow-molding the premix to obtain a degradable plastic film.

[0022] By adopting the above technical solution, the prepared degradable plastic film has both high strength and fast degradation speed, and can well meet the requirements of medical packaging for strength and degradation speed.

[0023] In summary, this application has the following beneficial effects: 1. Since the present application can accelerate the degradation of polypropylene by adding a degradation agent, and then by adding a degradable filler, the amount of polypropylene can be reduced, thereby further accelerating the degradation rate, so that the degradable plastic film can automatically rot and dissolve within a specified time (6 months to 1 year), thereby achieving an environmental protection effect.

[0024] 2. In the present application, it is preferred that the polylactic acid fiber is modified with a modifying liquid by using a degradable filler. After the polylactic acid fiber is modified with a modifying liquid prepared by compounding dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol, the strength of the polylactic acid fiber after being added to polypropylene can be improved, so that the plastic film can still have high strength under the premise of reducing the amount of polypropylene and adding a large amount of degradable filler, which can well meet the needs of medical packaging, thereby making the degradable plastic film have the advantages of high strength and fast degradation rate.

[0025] 3. In the present application, polylactic acid fibers are preferably selected so that the polylactic acid fibers can be better dispersed evenly when mixed with polypropylene resin. Moreover, since polylactic acid fibers have a larger specific surface area, the modification effect is better, thereby achieving a better effect of improving the strength of the degradable plastic film.

[0026] 4. In the present application, it is preferred to specifically select the mass ratio of aminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol to make the modified polylactic acid fiber more effective and improve the strength of the degradable plastic film, so that the degradable plastic film can better meet the needs of medical packaging and have better quality. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with embodiments.

[0028] Example 1 A degradable plastic film is made from the following components: Polypropylene resin, masterbatch, anti-blocking agent, gloss regulator, degradable filler, degrading agent.

[0029] The polypropylene resin was purchased from Sinopec, model K7726.

[0030] The masterbatch is PE masterbatch, purchased from Dongguan Zhengtao Plastic Co., Ltd., item number: HH9240IKNKJU.

[0031] The opening agent is erucamide, which is commercially available and has a CAS number of 112-84-5.

[0032] The gloss regulator is white mineral oil, purchased from Shandong Taichang Petrochemical Technology Co., Ltd., 5# white mineral oil.

[0033] The degradation agent is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, which is commercially available and has a CAS number of 24748-23-0.

[0034] The degradable filler is obtained by modifying polylactic acid fiber with a modifying liquid.

[0035] The modified liquid is a compound of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol.

[0036] The polylactic acid fiber was purchased from Nantong Yiheng New Material Technology Co., Ltd. with a thickness of 1.5D and a length of 2 mm.

[0037] Dimethylaminopropyl methacrylamide is commercially available, CAS number: 5205-93-6, content: 99%.

[0038] Isooctyl acrylate is commercially available, CAS No.: 29590-42-9, content: 99%.

[0039] Dimethyl sulfoxide is commercially available, CAS number: 67-68-5, content: 99%.

[0040] Allyl glycidyl ether is commercially available, CAS No.: 106-92-3, content: 99%.

[0041] The ethanol is commercially available, CAS No.: 64-17-5, and the content is 95%.

[0042] The preparation method of the degradable filler comprises the following steps: Step 1), 10kg of dimethylaminopropyl methacrylamide, 8kg of isooctyl acrylate, 3kg of dimethyl sulfoxide, 7kg of allyl glycidyl ether, and 100kg of ethanol are put into a stirring tank, the speed is 60r / min, stirred for 15min, and mixed evenly to obtain a modified liquid.

[0043] Step 2), weigh 100 kg of modified liquid and 100 kg of polylactic acid fiber and put them into a reactor, rotate at 30 r / min, stir continuously, keep constant temperature at 55°C, soak for 6 hours, filter out the polylactic acid fiber, and dry it in an oven at 100°C for 1 hour to obtain a degradable filler.

[0044] The preparation method of the degradable plastic film comprises the following steps: Step 01), put 100kg polypropylene resin, 3.5kg masterbatch, 1.8kg anti-blocking agent, 0.08kg gloss regulator, 40kg degradable filler, and 0.5kg degradation agent into a mixing tank, stir at 800r / min for 5min, mix evenly, and obtain a premix.

[0045] Step 02), the premix is ​​put into a twin-screw extruder to extrude a tube embryo, and the processing temperature of the twin-screw extruder I-XI zones is controlled to be set to: 165°C, 165°C, 175°C, 185°C, 195°C, 195°C, 195°C, 200°C, 200°C, 200°C, screw speed 40r / min, and the extruded tube embryo is blow-molded by a blow molding machine to obtain a degradable plastic film with a thickness of 0.2mm.

[0046] Example 2 A degradable plastic film is made from the following components: Polypropylene resin, masterbatch, anti-blocking agent, gloss regulator, degradable filler, degrading agent.

[0047] The polypropylene resin was purchased from Sinopec, model K7726.

[0048] The masterbatch is PE masterbatch, purchased from Dongguan Zhengtao Plastic Co., Ltd., item number: HH9240IKNKJU.

[0049] The opening agent is erucamide, which is commercially available and has a CAS number of 112-84-5.

[0050] The gloss regulator is white mineral oil, purchased from Shandong Taichang Petrochemical Technology Co., Ltd., 5# white mineral oil.

[0051] The degradation agent is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, which is commercially available and has a CAS number of 24748-23-0.

[0052] The degradable filler is obtained by modifying polylactic acid fiber with a modifying liquid.

[0053] The modified liquid is a compound of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol.

[0054] The polylactic acid fiber was purchased from Nantong Yiheng New Material Technology Co., Ltd. with a thickness of 1.5D and a length of 2 mm.

[0055] Dimethylaminopropyl methacrylamide is commercially available, CAS number: 5205-93-6, content: 99%.

[0056] Isooctyl acrylate is commercially available, CAS No.: 29590-42-9, content: 99%.

[0057] Dimethyl sulfoxide is commercially available, CAS number: 67-68-5, content: 99%.

[0058] Allyl glycidyl ether is commercially available, CAS No.: 106-92-3, content: 99%.

[0059] The ethanol is commercially available, CAS No.: 64-17-5, and the content is 95%.

[0060] The preparation method of the degradable filler comprises the following steps: Step 1), 11kg of dimethylaminopropyl methacrylamide, 9kg of isooctyl acrylate, 4kg of dimethyl sulfoxide, 8kg of allyl glycidyl ether, and 100kg of ethanol are put into a stirring tank, the speed is 60r / min, stirred for 15min, and mixed evenly to obtain a modified liquid.

[0061] Step 2), weigh 100 kg of modified liquid and 75 kg of polylactic acid fiber and put them into a reactor, rotate at 30 r / min, stir continuously, keep a constant temperature of 60°C, soak for 7 hours, filter out the polylactic acid fiber, and dry it in an oven at 100°C for 1 hour to obtain a degradable filler.

[0062] The preparation method of the degradable plastic film comprises the following steps: Step 01), put 100kg polypropylene resin, 4kg masterbatch, 2kg anti-blocking agent, 0.1kg gloss regulator, 45kg degradable filler, and 0.65kg degradation agent into a mixing tank, stir at 800r / min for 5min, mix evenly, and obtain a premix.

[0063] Step 02), the premix is ​​put into a twin-screw extruder to extrude a tube embryo, and the processing temperature of the twin-screw extruder I-XI zones is controlled to be set to: 165°C, 165°C, 175°C, 185°C, 195°C, 195°C, 195°C, 200°C, 200°C, 200°C, screw speed 40r / min, and the extruded tube embryo is blow-molded by a blow molding machine to obtain a degradable plastic film with a thickness of 0.2mm.

[0064] Example 3 A degradable plastic film is made from the following components: Polypropylene resin, masterbatch, anti-blocking agent, gloss regulator, degradable filler, degrading agent.

[0065] The polypropylene resin was purchased from Sinopec, model K7726.

[0066] The masterbatch is PE masterbatch, purchased from Dongguan Zhengtao Plastic Co., Ltd., item number: HH9240IKNKJU.

[0067] The opening agent is erucamide, which is commercially available and has a CAS number of 112-84-5.

[0068] The gloss regulator is white mineral oil, purchased from Shandong Taichang Petrochemical Technology Co., Ltd., 5# white mineral oil.

[0069] The degradation agent is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, which is commercially available and has a CAS number of 24748-23-0.

[0070] The degradable filler is obtained by modifying polylactic acid fiber with a modifying liquid.

[0071] The modified liquid is a compound of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol.

[0072] The polylactic acid fiber was purchased from Nantong Yiheng New Material Technology Co., Ltd. with a thickness of 1.5D and a length of 2 mm.

[0073] Dimethylaminopropyl methacrylamide is commercially available, CAS number: 5205-93-6, content: 99%.

[0074] Isooctyl acrylate is commercially available, CAS No.: 29590-42-9, content: 99%.

[0075] Dimethyl sulfoxide is commercially available, CAS number: 67-68-5, content: 99%.

[0076] Allyl glycidyl ether is commercially available, CAS No.: 106-92-3, content: 99%.

[0077] The ethanol is commercially available, CAS No.: 64-17-5, and the content is 95%.

[0078] The preparation method of the degradable filler comprises the following steps: Step 1), 12kg of dimethylaminopropyl methacrylamide, 10kg of isooctyl acrylate, 5kg of dimethyl sulfoxide, 9kg of allyl glycidyl ether, and 100kg of ethanol are put into a stirring tank, the speed is 60r / min, stirred for 15min, and mixed evenly to obtain a modified liquid.

[0079] Step 2), weigh 100 kg of modified liquid and 50 kg of polylactic acid fiber and put them into a reactor, rotate at 30 r / min, stir continuously, keep a constant temperature of 65°C, soak for 8 hours, filter out the polylactic acid fiber, and dry it in an oven at 100°C for 1 hour to obtain a degradable filler.

[0080] The preparation method of the degradable plastic film comprises the following steps: Step 01), put 100kg polypropylene resin, 4.5kg masterbatch, 2.2kg anti-blocking agent, 0.12kg gloss regulator, 50kg degradable filler, and 0.8kg degradation agent into a mixing tank, stir at 800r / min for 5min, mix evenly, and obtain a premix.

[0081] Step 02), the premix is ​​put into a twin-screw extruder to extrude a tube embryo, and the processing temperature of the twin-screw extruder I-XI zones is controlled to be set to: 165°C, 165°C, 175°C, 185°C, 195°C, 195°C, 195°C, 200°C, 200°C, 200°C, screw speed 40r / min, and the extruded tube embryo is blow-molded by a blow molding machine to obtain a degradable plastic film with a thickness of 0.2mm.

[0082] Comparative Example 1 A degradable plastic film, compared with Example 2, the only difference is: In the modified liquid, hydroxyethyl acrylate was used to replace dimethylaminopropyl methacrylamide in equal amount.

[0083] Hydroxyethyl acrylate is commercially available, CAS No.: 818-61-1, content: 99%.

[0084] Comparative Example 2 A degradable plastic film, compared with Example 2, the only difference is: In the modified liquid, silane coupling agent KH-550 was used to replace isooctyl acrylate in equal amounts.

[0085] The silane coupling agent KH-550 is commercially available, CAS number: 919-30-2, content: 99%.

[0086] Comparative Example 3 A degradable plastic film, compared with Example 2, the only difference is: In the modified solution, hydroxypropyl methacrylate was used to replace dimethyl sulfoxide in an equal amount.

[0087] Hydroxypropyl methacrylate is commercially available, CAS No.: 27813-02-1, content: 99%.

[0088] Comparative Example 4 A degradable plastic film, compared with Example 2, the only difference is: In the modified solution, isophthalic acid is used to replace allyl glycidyl ether in equal amounts.

[0089] Isophthalic acid is commercially available, CAS No.: 121-91-5, content: 99%.

[0090] Comparative Example 5 A degradable plastic film, compared with Example 2, the only difference is: In the modified liquid, hydroxyethyl acrylate was used to replace dimethylaminopropyl methacrylamide in equal amounts, silane coupling agent KH-550 was used to replace isooctyl acrylate in equal amounts, hydroxypropyl methacrylate was used to replace dimethyl sulfoxide in equal amounts, and isophthalic acid was used to replace allyl glycidyl ether in equal amounts.

[0091] Hydroxyethyl acrylate is commercially available, CAS No.: 818-61-1, content: 99%.

[0092] The silane coupling agent KH-550 is commercially available, CAS number: 919-30-2, content: 99%.

[0093] Hydroxypropyl methacrylate is commercially available, CAS No.: 27813-02-1, content: 99%.

[0094] Isophthalic acid is commercially available, CAS No.: 121-91-5, content: 99%.

[0095] Comparative Example 6 A degradable plastic film, compared with Example 2, the only difference is: Polylactic acid fiber is used to replace the degradable filler in equal amounts.

[0096] The polylactic acid fiber was purchased from Nantong Yiheng New Material Technology Co., Ltd. with a thickness of 1.5D and a length of 2 mm.

[0097] Comparative Example 7 A degradable plastic film, compared with Example 2, the only difference is: The biodegradable filler is replaced by an equal amount of polypropylene resin.

[0098] The polypropylene resin was purchased from Sinopec, model K7726.

[0099] Experiment 1 According to GB / T1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets", the tensile strength (MPa) of the test samples made of the degradable plastic films of each embodiment and comparative example was tested.

[0100] Experiment 2 The degradable plastic films of the embodiments and comparative examples were cut into test samples with a length of 10 cm and a width of 10 cm. The test samples were buried in soil, and the degradation conditions were observed and recorded after 6 months.

[0101] The specific test data of Experiments 1 and 2 are shown in Table 1.

[0102] Table 1 According to the data comparison of each embodiment and comparative example in Table 1, each embodiment and comparative examples 1-6 have been significantly degraded after 6 months in the soil, and the degree of degradation is significantly higher than that of comparative example 7, which proves that adding a large amount of degradable filler to polypropylene can effectively improve the degradation performance of the plastic film.

[0103] The tensile strength of each embodiment is similar to that of Comparative Example 6 and significantly higher than that of Comparative Examples 1-6. It can be seen that after the polylactic acid fiber is modified with a special modifying liquid prepared by mixing dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether, and ethanol, the strength of the degradable plastic film can be significantly improved, and the strength decrease caused by the large amount of degradable fillers added can be reduced, so that the strength of the plastic film is close to that of the plastic film without degradable fillers.

[0104] Comparative Examples 1-5 use other modifiers to replace the dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, and allyl glycidyl ether in each embodiment alone or in whole. Although they can also modify the polylactic acid fiber and the strength is higher than that of Comparative Example 6 in which unmodified polylactic acid fiber is added, the modification effect is relatively general, resulting in a significant decrease in the strength of the plastic films of Comparative Examples 1-5.

[0105] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A degradable plastic film, characterized in that: It is prepared from the following components in parts by weight: 100 parts of polypropylene resin; Masterbatch 3.5-4.5 parts; 1.8-2.2 parts of opening agent; Gloss regulator 0.08-0.12 parts; 40-50 parts of degradable filler; Degradation agent 0.5-0.8 parts; The degradable filler is obtained by modifying polylactic acid fiber with a modifying liquid; The modified liquid is a compound of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol.

2. A degradable plastic film according to claim 1, characterized in that: In the modified liquid, the mass ratio of dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether and ethanol is 10-12:8-10:3-5:7-9:

100.

3. A degradable plastic film according to claim 2, characterized in that: The preparation method of the degradable filler comprises the following steps: Step 1), dimethylaminopropyl methacrylamide, isooctyl acrylate, dimethyl sulfoxide, allyl glycidyl ether, and ethanol are mixed to prepare a modified liquid; Step 2), putting the polylactic acid fiber into the modified liquid, keeping the temperature at 55-65°C, soaking for 6-8 hours, filtering out and drying to obtain the degradable filler.

4. A degradable plastic film according to claim 3, characterized in that: In the step 2), the mass ratio of the polylactic acid fiber to the modified liquid is 1:1-2.

5. The degradable plastic film according to claim 1, characterized in that: The opening agent is erucamide.

6. The degradable plastic film according to claim 1, characterized in that: The gloss regulator is white mineral oil.

7. The degradable plastic film according to claim 1, characterized in that: The degradation agent is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane.

8. A method for preparing a degradable plastic film according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 01), polypropylene resin, masterbatch, anti-blocking agent, gloss regulator, degradable filler, and degradation agent are mixed to obtain a premix; Step 02), the premix is ​​extruded and blow-molded to obtain a degradable plastic film.

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