High-antibacterial PETG (polyethylene terephthalate glycol) composite material as well as preparation method and application thereof

Abstract

The invention relates to a high-antibacterial PETG composite material as well as a preparation method and application thereof. The high-antibacterial PETG composite material comprises the following raw materials in parts by mass: 100 parts of PETG, 2-5 parts of a composite antibacterial agent, 3-10 parts of a silane coupling agent and 0.1-0.3 part of an initiator, wherein the composite antibacterial agent is a composition of propyl gallate, hexamidine diisethionate and polyhexamethylene biguanide hydrochloride. The invention further discloses a preparation method of the antibacterial agent. The composite antibacterial agent can be stably combined with a PETG matrix under the action of a coupling agent and an initiator. The PETG composite material has processing feasibility and long-acting antibacterial property through the synergistic effect of the composite antibacterial agent, the coupling agent and the initiator.

Description

Technical Field

[0001] The present invention relates to the technical field of PETG composites, and particularly relates to a highly antibacterial PETG composite material, a preparation method thereof, and an application thereof. Background Art

[0002] In the process of compounding antibacterial agents with PETG, there are a series of significant drawbacks. First of all, the compatibility problem is particularly prominent: some inorganic antibacterial agents, such as silver ions, are prone to agglomeration due to the significant polarity difference with PETG, resulting in too high local concentration or the formation of antibacterial blind spots; at the same time, the processing temperature of PETG (about 220 - 250 °C) may damage the structure of organic antibacterial agents (such as quaternary ammonium salts), causing discoloration or decomposition; in addition, low-compatibility antibacterial agents are also prone to migrate from the PETG matrix to the surface, not only causing waste of antibacterial agents, but also potentially polluting the contacted articles, such as the exudation of silver ions in food packaging. Secondly, there are obvious defects in long-term antibacterial performance: antibacterial agents relying on the dissolution mechanism (such as nano silver) release too fast in the initial stage and the concentration is insufficient in the later stage, making it difficult to cope with long-term microbial challenges; light / oxygen-sensitive antibacterial agents (such as titanium dioxide) are easily inactivated in outdoor applications, and their long-term effectiveness is limited to laboratory conditions; the sprayed antibacterial layer quickly falls off under mechanical friction, and it is impossible to achieve persistent antibacterial of the material body, such as the failure of medical devices after repeated disinfection. More intractably, safety and regulatory restrictions have banned some highly effective antibacterial agents (such as triclosan) from being used in food-contact PETG due to potential toxicity, forcing manufacturers to switch to low-efficiency alternatives. Finally, the balance between cost and performance has also become a major problem: high-loading antibacterial agents can improve antibacterial effects, but significantly increase the brittleness of the material (such as a more than 30% decrease in the elongation at break of PETG), severely restricting its application in scenarios with high toughness requirements. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a highly antibacterial PETG composite material, a preparation method thereof, and an application thereof.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows: In the first aspect, the present invention provides a highly antibacterial PETG composite material, comprising the following raw materials in parts by mass: 100 parts of PETG, 2 - 5 parts of a composite antibacterial agent, 3 - 10 parts of a silane coupling agent, and 0.1 - 0.3 parts of an initiator; wherein, the composite antibacterial agent is a composition of propyl gallate, hexamidine dihydroxyethyl sulfonate, and polyhexamethylene biguanide hydrochloride.

[0005] The composite antibacterial agents of the present invention are all organic antibacterial agents, which avoid the situation that the free movement space of polymer molecular chains is reduced due to the addition of a large amount of inorganic antibacterial agent particles (such as silver and zinc), restricting the deformation ability of the material and resulting in a decrease in the elongation at break. Therefore, the PETG composite material of the present invention can maintain good mechanical properties. Polyhexamethylene biguanide hydrochloride (PHMB) is a high-molecular guanidine salt antibacterial agent. A large number of amino groups in its molecular chain are combined with the ester groups of PETG through hydrogen bonding, and the introduction of a silane coupling agent can further improve the interfacial compatibility. Propyl gallate and hexamidine dihydroxyethyl sulfonate are low-molecular organic antibacterial agents, and through the action of a coupling agent and an initiator, stable binding in the PETG matrix can be achieved. PHMB belongs to a non-eluting antibacterial agent (sterilizing by contact). The antibacterial groups are fixed on the material surface through chemical bonds, resistant to washing and friction, and the long-term antibacterial effect is stable. Propyl gallate and hexamidine dihydroxyethyl sulfonate are eluting antibacterial agents. Therefore, PHMB in the composite antibacterial agent provides a long-term antibacterial base, and propyl gallate and hexamidine dihydroxyethyl sulfonate supplement short-term rapid sterilization. At the same time, the silane coupling agent can effectively prevent the loss of propyl gallate and hexamidine dihydroxyethyl sulfonate and extend the overall antibacterial life.

[0006] In addition, propyl gallate has certain antioxidant properties. It can, to a certain extent, prevent the degradation reaction of PETG materials due to oxidation during processing, storage or use, and maintain the integrity of the polymer chain, which is beneficial to maintaining the original mechanical properties of the material. The sulfonic acid group of hexamidine dihydroxyethyl sulfonate can form an ion pair with the silane coupling agent to construct a three-dimensional crosslinked network and improve the mechanical properties. The molecular chain of polyhexamethylene biguanide hydrochloride is relatively long and contains guanidine groups. The guanidine groups have strong polarity. On the one hand, it can form weak interactions such as hydrogen bonds with the PETG molecular chain, enhancing the force between molecular chains and increasing the tensile strength; on the other hand, the long-chain structure can play a buffering role when the material is stretched, preventing stress concentration and avoiding premature fracture of the material, thereby having a beneficial effect on the elongation at break.

[0007] In summary, through the synergistic effect of the composite antibacterial agent, the coupling agent and the initiator, the PETG composite material has both processing feasibility and long-term antibacterial properties.

[0008] Preferably, the mass ratio of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride is 1:(2 - 3):(2 - 3).

[0009] Preferably, the composite material comprises the following raw materials in parts by mass: 100 parts of PETG, 4 - 5 parts of composite antibacterial agent, 6 - 10 parts of silane coupling agent and 0.1 - 0.2 part of initiator; Preferably, the silane coupling agent comprises at least one of KH550, KH560, KH570, KH792, DL602.

[0010] Preferably, the initiator is an azo initiator.

[0011] In a second aspect, the present invention provides a method for preparing a highly antibacterial PETG composite material, comprising the following steps: S1. After mixing the composite antibacterial agent and the silane coupling agent, an initiator is added, and the reaction is carried out at 70 - 80 °C for 2 - 3 h to obtain a mixture; S2. Mix PETG and the mixture, and granulate at 210 - 240 °C to obtain the highly antibacterial PETG composite material.

[0012] Preferably, in the step S1, the mixing rotation speed is 800 - 1000 rpm, and the mixing time is 30 - 60 min.

[0013] In a third aspect, the present invention provides the application of the highly antibacterial PETG composite material in the preparation of medical packaging materials.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The composite antibacterial agent in the PETG composite material of the present invention is a composition of polyhexamethylene biguanide hydrochloride, propyl gallate, and hexamidine dihydroxyethyl sulfonate. Through the action of the coupling agent and the initiator, the composite antibacterial agent can be stably combined with the PETG matrix. Among them, PHMB belongs to a non - leaching antibacterial agent, and the long - term antibacterial effect is stable. Propyl gallate and hexamidine dihydroxyethyl sulfonate belong to leaching antibacterial agents. In the composite antibacterial agent, PHMB provides a long - term antibacterial base, and propyl gallate and hexamidine dihydroxyethyl sulfonate supplement short - term rapid sterilization. At the same time, the silane coupling agent can effectively prevent the loss of propyl gallate and hexamidine dihydroxyethyl sulfonate and extend the overall antibacterial life. Through the synergistic effect of the composite antibacterial agent, the coupling agent, and the initiator, the PETG composite material has both processing feasibility and long - term antibacterial properties. Specific Embodiments

[0015] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0016] The sources of the raw materials used in the following examples and comparative examples are as follows: PETG: The manufacturer is SK Corporation of South Korea, and the grade is K2012; Propyl gallate: The manufacturer is Guangdong Wengjiang Chemical Reagent Co., Ltd., and the model is PA01812; Hexamidine dihydroxyethyl sulfonate: The manufacturer is Guangzhou Weixi Biotechnology Co., Ltd., and the model is 988; Polyhexamethylene biguanide hydrochloride: The manufacturer is Guangdong Wengjiang Chemical Reagent Co., Ltd., and the model is PC97458; Silane coupling agents: KH550, KH560, and KH570 were all purchased from Shanghai Yuanye Bio-Technology Co., Ltd.; Azo initiator: azodiisobutyronitrile, manufactured by Guangdong Wengjiang Chemical Reagent Co., Ltd., with the product number WA01724; Other materials, reagents, etc. used in the examples, unless otherwise specified, can be obtained through commercial channels.

[0017] Example 1

[0018] A highly antibacterial PETG composite material, comprising the following raw materials by mass: 100 parts of PETG, 4 parts of composite antibacterial agent, 6 parts of silane coupling agent, and 0.2 part of initiator; wherein, the composite antibacterial agent is a composition of propyl gallate, hexamidine dihydroxyethyl sulfonate, and polyhexamethylene biguanide hydrochloride with a mass ratio of 1:3:2; the silane coupling agent is KH560; the initiator is an azo initiator.

[0019] A preparation method of the highly antibacterial PETG composite material, comprising the following steps: S1. Mix the composite antibacterial agent and the silane coupling agent at 850 rpm for 40 min, then add the initiator, and react at 75 °C for 3 h to obtain a mixture; S2. Mix PETG and the mixture, and granulate at 230 °C to obtain the highly antibacterial PETG composite material.

[0020] Example 2 A highly antibacterial PETG composite material, comprising the following raw materials by mass: 100 parts of PETG, 2 parts of composite antibacterial agent, 3 parts of silane coupling agent, and 0.1 part of initiator; wherein, the composite antibacterial agent is a composition of propyl gallate, hexamidine dihydroxyethyl sulfonate, and polyhexamethylene biguanide hydrochloride with a mass ratio of 1:2:2; the silane coupling agent is KH550; the initiator is an azo initiator.

[0021] A preparation method of the highly antibacterial PETG composite material, comprising the following steps: S1. Mix the composite antibacterial agent and the silane coupling agent at 800 rpm for 60 min, then add the initiator, and react at 70 °C for 3 h to obtain a mixture; S2. Mix PETG and the mixture, and granulate at 210 °C to obtain the highly antibacterial PETG composite material.

[0022] Example 3 A highly antibacterial PETG composite material, comprising the following raw materials by mass: 100 parts of PETG, 5 parts of composite antibacterial agent, 10 parts of silane coupling agent and 0.3 parts of initiator; wherein, the composite antibacterial agent is a composition of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride with a mass ratio of 1:3:3; the silane coupling agent is KH570; the initiator is an azo initiator.

[0023] Preparation method of highly antibacterial PETG composite material, comprising the following steps: S1. After mixing the composite antibacterial agent and the silane coupling agent at 1000 rpm for 30 min, then adding the initiator, and reacting at 80 °C for 2 h to obtain a mixture; S2. Mix PETG and the mixture, and granulate at 240 °C to obtain the highly antibacterial PETG composite material.

[0024] Example 4 The difference between Example 4 and Example 1 is that: the total mass of the composite antibacterial agent remains unchanged, and the mass ratio of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride is 2:3:1.

[0025] Example 5 The difference between Example 5 and Example 1 is that: the total mass of the composite antibacterial agent remains unchanged, and the mass ratio of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride is 3:1:2.

[0026] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that: Comparative Example 1 does not add silane coupling agent and initiator.

[0027] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that: propyl gallate is not added to the composite antibacterial agent, and the missing amount is supplemented with hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride with a mass ratio of 3:2.

[0028] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that: hexamidine dihydroxyethyl sulfonate is not added to the composite antibacterial agent, and the missing amount is supplemented with propyl gallate and polyhexamethylene biguanide hydrochloride with a mass ratio of 1:2.

[0029] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that: polyhexamethylene biguanide hydrochloride is not added to the composite antibacterial agent, and the missing amount is supplemented with propyl gallate and hexamidine dihydroxyethyl sulfonate with a mass ratio of 1:3.

[0030] Performance test 1. Mechanical property test Referring to the national standard GB / T 1040.2-2006 "Test Method for Tensile Properties of Plastics", the tensile strength and elongation at break of the splines made of the highly antibacterial PETG composites of Examples 1-5 and Comparative Examples 1-4 were measured. Tensile speed: 50 mm / min. To ensure the accuracy of the experiment, 5 specimens were taken for each component, and the data were processed by the method of taking the average value. The test results are shown in Table 1.

[0031] 2. Long-term antibacterial performance test According to QB / T 2591-2003 "Test Method and Antibacterial Effect of Antibacterial Plastics", the antibacterial properties of the highly antibacterial PETG composites prepared in Examples 1-5 and Comparative Examples 1-4 were measured. Their antibacterial properties and antibacterial properties after being placed for 80 days at a temperature of 50 °C and a humidity of 80% were measured respectively. The test results are shown in Table 1.

[0032] Table 1 Mechanical properties and long-term antibacterial performance data of each group of samples Group Tensile strength / MPa Elongation at break / % Antibacterial rate after 80 days / % Example 1 74.9 215 99.7 Example 2 72.8 208 99.1 Example 3 74.0 213 99.6 Example 4 68.5 186 96.1 Example 5 69.8 183 96.4 Comparative example 1 42.1 112 62.0 Comparative example 2 55.8 164 74.2 Comparative example 3 56.6 168 74.9 Comparative example 4 52.8 155 72.1 As can be seen from Table 1, combining the data of Example 1 and Examples 4-5, when the mass ratio of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride is 1:(2-3):(2-3), the long-term antibacterial effect and mechanical properties of the composite material are better.

[0033] Combining the data of Example 1 and Comparative Example 1, it can be seen that the mechanical properties and antibacterial rate of Comparative Example 1 decreased significantly compared with those of Example 1. This shows that the composite antibacterial agent realizes the stable combination of the composite antibacterial agent in the PETG matrix through the action of the coupling agent and the initiator.

[0034] Combining the data of Example 1 and Comparative Examples 2-4, it can be seen that the 80-day antibacterial rate, tensile strength and elongation at break of Example 1 have all increased. This shows that polyhexamethylene biguanide hydrochloride, propyl gallate and hexamidine dihydroxyethyl sulfonate can synergistically improve the long-term antibacterial performance of the PETG composite material. At the same time, the compatibility of the three with PETG through the silane coupling agent is good, and they can also synergistically improve the mechanical properties of the PETG composite material.

[0035] In summary, the present invention selects a specific composite antibacterial agent to successfully achieve the synergistic improvement of the antibacterial rate and mechanical properties through the bridging action of silane and the free radical grafting reaction of the initiator, and is particularly suitable for scenarios such as medical packaging that require both antibacterial and flexibility.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A highly antibacterial PETG composite material, characterized in that: Including the following raw materials by weight: 100 parts of PETG, 2-5 parts of composite antibacterial agent, 3-10 parts of silane coupling agent and 0.1-0.3 parts of initiator; wherein the composite antibacterial agent is a composition of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride.

2. The highly antibacterial PETG composite material as claimed in claim 1, characterized in that: The mass ratio of propyl gallate, hexamidine dihydroxyethyl sulfonate and polyhexamethylene biguanide hydrochloride is 1:(2-3):(2-3).

3. The highly antibacterial PETG composite material as claimed in claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of PETG, 4-5 parts of composite antibacterial agent, 6-10 parts of silane coupling agent and 0.1-0.2 parts of initiator.

4. The highly antibacterial PETG composite material as claimed in claim 1, characterized in that: The silane coupling agent includes at least one of KH550, KH560, KH570, KH792, and DL602.

5. The highly antibacterial PETG composite material as claimed in claim 1, characterized in that: The initiator is an azo initiator.

6. The method for preparing the highly antibacterial PETG composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. After mixing the composite antibacterial agent and the silane coupling agent, an initiator is added, and the mixture is reacted at 70-80° C. for 2-3 hours to obtain a mixture; S2, mixing PETG and the mixture, and granulating at 210-240° C. to obtain the highly antibacterial PETG composite material.

7. The method for preparing the highly antibacterial PETG composite material as claimed in claim 6, characterized in that: In step S1, the mixing speed is 800-1000 rpm, and the mixing time is 30-60 min.

8. Use of the highly antibacterial PETG composite material according to any one of claims 1 to 5 in the preparation of medical packaging materials.