CN102796355A - Antibacterial plastic and preparation method thereof - Google Patents

Abstract

The invention provides an antibacterial plastic and a preparation method thereof. The antibacterial plastic comprises polyethylene terephthalate resin with a mass fraction of 45-95%, chitin fiber with 4-50%, and chitin fiber with 0.2-3% Compatilizer, 0.1-0.5% antioxidant. The present invention has the following beneficial effects: the highly filled chitin fiber reinforced antibacterial PBT plastic of the present invention, the antibacterial agent is natural biological fiber chitin, while enhancing the mechanical properties of the material, it also has good antibacterial performance and meets the requirements of long-acting antibacterial , and non-toxic, environmentally friendly. The preparation method of the highly filled chitin fiber reinforced antibacterial PBT plastic of the present invention adopts a twin-screw extruder to carry out melt mixing reaction extrusion granulation, and the whole process is simple and environment-friendly. The highly filled chitin fiber reinforced antibacterial PBT plastic of the invention can obtain a PBT composite material filled up to 50%.

Description

A kind of antibacterial plastic and preparation method thereof

【Technical field】

The invention relates to the technical field of polymer plastics, in particular to an antibacterial plastic and a preparation method thereof. the

【Background technique】

At present, the preparation method of antibacterial plastics is mainly made by adding a small amount of antibacterial agents, blending and compounding, and its active ingredients are antibacterial agents. , The application is more common, but most inorganic antibacterial agents are heavy metal ions, such as nano-silver, which are highly toxic to the human body and cause environmental pollution. The main varieties of organic antibacterial agents include aromatic aldehydes, ethyl vanillin compounds, quaternary ammonium salts and biguanides, etc. Organic antibacterial agents have poor temperature resistance and may dissolve and precipitate after long-term use. the

Polyethylene terephthalate (PBT) is formed by the condensation of 1.4-butanediol and terephthalic acid or terephthalate, and is milky white translucent to opaque, Crystalline thermoplastic polyester resin. PBT resin is the latest and fastest-growing variety of general engineering plastics. PBT resin has excellent comprehensive properties such as high heat resistance, toughness, fatigue resistance, self-lubrication, low friction coefficient, weather resistance, and low water absorption, but pure PBT resin has low notched impact strength and large molding shrinkage. Therefore, glass fibers or inorganic fillers are often used for modification. The viscosity of commercially available modified polyethylene terephthalate resin (PBT resin) is higher, and the proportion of PBT resin is larger, and it is difficult to obtain a highly filled PBT composite material, so the antibacterial material prepared with PBT resin is very difficult. Difficult to obtain good antibacterial effect. the

【Content of invention】

The technical problem to be solved by the present invention is to provide an antibacterial plastic, which comprises polyethylene terephthalate resin with a mass fraction of 45-95%, chitin fiber of 4-50%, 0.2-3 % compatibilizer, 0.1-0.5% antioxidant. the

Preferably, the mass fraction of the polyethylene terephthalate resin is 46.5-94.7%. the

Preferably, the chitin fiber is β-chitin, more preferably, the antibacterial agent is β-chitin extracted from squid cartilage. the

Preferably, the compatibilizer is a silane coupling agent or a titanate coupling agent. the

Optionally, the antioxidant is a mixture of phenolic antioxidant or phosphite antioxidant or phenolic antioxidant and phosphite antioxidant; preferably, the phenolic antioxidant Tetrakis[β-(3', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] pentaerythritol ester, the phosphite antioxidant is (2,4 di-tert-butylphenyl ) Phosphite triester. the

The present invention also provides a kind of preparation method of antibacterial plastic, comprises the following steps:

Take CBT resin as the matrix, add chitin fiber, compatibilizer and antioxidant according to the components, and mix well;

The uniformly mixed material is extruded and granulated to obtain granular antibacterial plastics. the

During specific implementation, the homogeneously mixed material is extruded and granulated through a twin-screw extruder. the

During specific implementation, the process parameters of extrusion and granulation of the twin-screw extruder are set as follows: the temperature in the first zone is 120-140°C, the temperature in the second zone is 160-190°C, and the temperature in the third zone is 190-210°C. The temperature of the fourth zone is 210-230°C, the temperature of the fifth zone is 210-230°C, the temperature of the sixth zone is 210-230°C, and the temperature of the seventh zone is 230-250°C; the speed of the host is 300-350rpm. the

The antibacterial plastic of the present invention uses CBT resin as plastic base material, and CBT resin is the low molecular weight cyclic oligomer of polybutylene terephthalate (PBT resin), and CBT resin has macrocyclic oligoester structure, is different A mixture of low molecular weight cyclic oligomers, which can be reacted and polymerized into high molecular weight PBT resin under heated conditions. When CBT resin is heated, it will become like water, with extremely low viscosity, and its melt viscosity is as low as 18MPa.s at 200°C. The present invention utilizes its low-viscosity characteristics and adds chitin as an antibacterial agent to obtain high filling Composite antibacterial plastics. the

Chitin is an amino polysaccharide that exists widely in nature. Chitin is a natural antibacterial substance with good antibacterial properties. Compared with other disinfectants, chitosan has the advantages of strong bactericidal ability, wide antibacterial ability, and no cytotoxicity to mammals. There are three crystal forms of chitin in nature, α, β, and γ-crystal forms. Among them, the molecular chains of β-chitin are arranged in parallel to each other, which belongs to the monoclinic crystal system. Because of the parallel crystal structure of β-chitin molecules, short fibers can be obtained after crushing β-chitin obtained in nature. The present invention uses chitin fiber as an antibacterial agent and adds it to CBT resin to obtain a high filling rate. the

In the preparation process of the present invention, firstly, low-viscosity CBT resin is used as a base material, chitin fibers, compatibilizers and antioxidants are added and mixed evenly, and then extruded and granulated by a twin-screw extruder. Under these conditions, CBT resin is polymerized into high molecular weight PBT resin to obtain antibacterial PBT plastic. the

By using the antibacterial plastic according to the present invention and the preparation method thereof, it has the following beneficial effects: the highly filled chitin fiber reinforced antibacterial PBT plastic of the present invention, the antibacterial agent is natural biological fiber chitin, while enhancing the mechanical properties of the material, it also has Good antibacterial properties, meet the requirements of long-term antibacterial, and non-toxic, environmentally friendly. The preparation method of the highly filled chitin fiber reinforced antibacterial PBT plastic of the present invention adopts a twin-screw extruder to carry out melt mixing reaction extrusion granulation, and the whole process is simple and environment-friendly. the

The highly filled chitin fiber reinforced antibacterial PBT plastic of the invention can obtain a PBT composite material filled up to 50%. the

【Detailed ways】

The present invention will be described in detail below in conjunction with examples. the

Example 1:

An antibacterial plastic, the mass ratio is as follows:

Polyethylene terephthalate resin 95%, chitin fiber 4.7%, compatibilizer Y-aminopropyltriethoxysilane 0.2%, antioxidant tetrakis[β-(3,5-di-tert-butyl Base-4-hydroxyphenyl) propionate] pentaerythritol ester 0.1%. the

Its preparation process is as follows:

(1) Weigh the components by mass percentage: CBT resin (using CBT160 of Cyclics Company) mass ratio 95%; chitin fiber mass ratio 4.7%; compatibilizer Y-aminopropyltriethoxysilane (using Chenguang Chemical KH-550) mass ratio 0.2%; Antioxidant 1010 (i.e. tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester) mass ratio 0.1%;

(2) Mix the above materials in a high-speed mixer for 10 minutes;

(3) Put the homogeneously mixed material in a twin-screw extruder, melt, mix, extrude and granulate. The process parameters of the twin-screw extruder are set as follows: the temperature in the first zone is 120-140°C, and the temperature in the second zone is 160°C. -190°C, the temperature in the third zone is 190-210°C, the temperature in the fourth zone is 210-230°C, the temperature in the fifth zone is 210-230°C, the temperature in the sixth zone is 210-230°C, and the temperature in the seventh zone is 230-250°C; The speed is 300-350rpm. the

Example 2:

An antibacterial plastic, the mass ratio is as follows:

Polyethylene terephthalate resin 80%, chitin fiber 18.5%, compatibilizer 1.2%, antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid Esters] Pentaerythritol Ester 0.3%. the

Its preparation process is as follows:

(1) Weigh the components by mass percentage: CBT resin (using CBT160 of Cyclics Company) mass ratio of 80%; chitin fiber mass ratio of 18.5%; compatibilizer Y-aminopropyltriethoxysilane (using Chenguang Chemical KH-550) mass ratio 1.2%; Antioxidant 1010 (i.e. tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester) mass ratio 0.3%;

(2) Mix the above materials in a high-speed mixer for 10 minutes;

(3) Put the homogeneously mixed material in a twin-screw extruder, melt, mix, extrude and granulate. The process parameters of the twin-screw extruder are set as follows: the temperature in the first zone is 120-140°C, and the temperature in the second zone is 160°C. -190°C, the temperature in the third zone is 190-210°C, the temperature in the fourth zone is 210-230°C, the temperature in the fifth zone is 210-230°C, the temperature in the sixth zone is 210-230°C, and the temperature in the seventh zone is 230-250°C; The speed is 300-350rpm. the

Example 3:

An antibacterial plastic, the mass ratio is as follows:

Polyethylene terephthalate resin 60%, chitin fiber 37.6%, compatibilizer Y-aminopropyltriethoxysilane 2%, antioxidant (2,4 di-tert-butylphenyl) Phosphate Triesters 0.4%. the

Its preparation process is as follows:

(1) Weigh the components by mass percentage: CBT resin (CBT160 from Cyclics Company) mass ratio 60%; chitin fiber mass ratio 37.6%; compatibilizer Y-aminopropyltriethoxysilane (Chenguang Chemical KH-550) mass ratio 2%; antioxidant (2,4 di-tert-butylphenyl) phosphite triester mass ratio 0.4%;

(2) Mix the above materials in a high-speed mixer for 10 minutes;

(3) Put the homogeneously mixed material in a twin-screw extruder, melt, mix, extrude and granulate. The process parameters of the twin-screw extruder are set as follows: the temperature in the first zone is 120-140°C, and the temperature in the second zone is 160°C. -190°C, the temperature in the third zone is 190-210°C, the temperature in the fourth zone is 210-230°C, the temperature in the fifth zone is 210-230°C, the temperature in the sixth zone is 210-230°C, and the temperature in the seventh zone is 230-250°C; The speed is 300-350rpm. the

Example 4:

An antibacterial plastic, the mass ratio is as follows:

Polyethylene terephthalate resin 50%, chitin fiber 46.5%, compatibilizer Y-aminopropyltriethoxysilane 3%, antioxidant (2,4 di-tert-butylphenyl) Phosphate Triesters 0.5%. the

Its preparation process is as follows:

(1) Weighing components by mass percentage: CBT resin (CBT160 by Cyclics Company) mass ratio 50%; chitin fiber mass ratio 46.5%; compatibilizer Y-aminopropyltriethoxysilane mass ratio 3% ; Antioxidant (2,4 di-tert-butylphenyl) phosphite triester mass ratio 0.5%;

(2) Mix the above materials in a high-speed mixer for 10 minutes;

(3) Put the homogeneously mixed material in a twin-screw extruder, melt, mix, extrude and granulate. The process parameters of the twin-screw extruder are set as follows: the temperature in the first zone is 120-140°C, and the temperature in the second zone is 160°C. -190°C, the temperature in the third zone is 190-210°C, the temperature in the fourth zone is 210-230°C, the temperature in the fifth zone is 210-230°C, the temperature in the sixth zone is 210-230°C, and the temperature in the seventh zone is 230-250°C; The speed is 300-350rpm. the

The antibacterial plastic granule that above-mentioned embodiment makes is carried out performance test below:

The antibacterial plastic granules prepared by the above-mentioned examples were cross-linked in a blast oven at 200 to 210° C. for 4 hours in advance, and then the cross-linked and dried granules were injection-molded on an injection machine for sample preparation. Control at 80°C, injection molding temperature at 230-270°C. the

The tensile performance test is carried out according to ISO527-2, the sample size is 150×10×4, and the tensile speed is 50mm/min; the bending performance test is carried out according to ISO178, the sample size is 80×10×4, and the tensile speed is 2mm /min, the span is 64mm, the Charpy impact strength is tested according to ISO179, the sample size is 55×6×4, and the notch depth is one-third of the thickness of the sample. the

The comprehensive mechanical properties of the material are judged by the values of tensile strength, elongation at break, flexural strength, flexural modulus and impact strength. The formula of PBT resin and embodiment 1-4 and mechanical property comparison table are as shown in table 1. the

Table 1

Material name PBT resin Example 1 Example 2 Example 3 Example 4 PBT resin content 100 95 80 60 50 Chitin fiber content - 4.7 18.5 37.6 46.5 Compatibilizer content - 0.2 1.2 2 3 Antioxidant content - 0.1 0.3 0.4 0.5 specific gravity 1.31 1.30 1.27 1.25 1.22 Bending strength (Mpa) 82 85 97 120 122 Bending modulus (Mpa) 2250 2339 2750 3651 3677 Notched Impact Strength (kJ/m ² ) 3 3 2.9 3.2 2.9 Tensile strength (Mpa) 55 57 63 75 77 Elongation at break (%) 40 8 1.4 0.5 0.4

The antibacterial performance of the material is tested according to the test method specified in the "QB/T 2591-2003 Antibacterial Plastic Antibacterial Performance Test Method and Antibacterial Effect" standard. The bacteria tested are Staphylococcus aureus ATCC 6538 (Gram-positive bacteria) and Escherichia coli Helicobacter ATCC25922 (Gram-negative bacteria), fungal test bacteria species is Candida albicans ATCC 10231. PBT resin and embodiment 1-4 obtained material surface antimicrobial performance comparative table are as shown in table 2. the

Table 2

From the performance comparison in Table 1, it can be seen that with the increase of the mass ratio of chitin fibers, the comprehensive mechanical properties of the material increase, but from Table 2, it can be seen that the antibacterial properties of materials are enhanced with the increase of the mass ratio of chitin fibers, and 37.6% antibacterial agent The filled material has a strong ability to resist bacteria and mold. the

In the above embodiments, the present invention is only described as an example, but those skilled in the art can make various modifications to the present invention without departing from the spirit and scope of the present invention after reading this patent application. the

Claims (10)

1. an antibacterial plastic, is characterized in that: described antibacterial plastic comprises the polyethylene terephthalate resin that massfraction is 45-95%, the chitin fiber of 4-50%, the phase of 0.2-3% Compatible agent, 0.1-0.5% antioxidant. 2. The antibacterial plastic according to claim 1, characterized in that: the mass fraction of the polyethylene terephthalate resin is 46.5-94.7%. 3. The antibacterial plastic according to claim 1, characterized in that: the chitin fiber is β-chitin. 4. The antibacterial plastic according to claim 3, characterized in that: the antibacterial agent is β-chitin extracted from squid cartilage. 5. The antibacterial plastic according to claim 1, characterized in that: the compatibilizer is a silane coupling agent or a titanate coupling agent. 6. antibacterial plastics according to claim 1, is characterized in that: described antioxidant is the combination of phenolic antioxidant or phosphite antioxidant or phenolic antioxidant and phosphite antioxidant mixture. 7. The antibacterial plastic according to claim 6, characterized in that: said phenolic antioxidant is tetrakis [β-(3', 5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid] Pentaerythritol ester, the phosphite antioxidant is (2,4 di-tert-butylphenyl) phosphite triester. 8. A preparation method of antibacterial plastic, is characterized in that, comprises the following steps: Take CBT resin as the matrix, add chitin fiber, compatibilizer and antioxidant according to the proportion of the components, and mix evenly; The uniformly mixed material is extruded and granulated to obtain granular antibacterial plastics. 9. The preparation method of antibacterial plastics according to claim 8, characterized in that, the uniformly mixed material is extruded and granulated by a twin-screw extruder. 10. the preparation method of antibacterial plastics according to claim 9, is characterized in that, described twin-screw extruder carries out the processing parameter setting of extruding granulation as follows: the temperature in the first zone is 120-140 ℃, and the temperature in the second zone is 160-190°C, the temperature in the third zone is 190-210°C, the temperature in the fourth zone is 210-230°C, the temperature in the fifth zone is 210-230°C, the temperature in the sixth zone is 210-230°C, and the temperature in the seventh zone is 230-250°C; The host speed is 300-350rpm.