CN113429768B - Polylactic acid composition containing amide nucleating agent and preparation method thereof - Google Patents
Polylactic acid composition containing amide nucleating agent and preparation method thereof Download PDFInfo
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- CN113429768B CN113429768B CN202110806358.3A CN202110806358A CN113429768B CN 113429768 B CN113429768 B CN 113429768B CN 202110806358 A CN202110806358 A CN 202110806358A CN 113429768 B CN113429768 B CN 113429768B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/20—Carboxylic acid amides
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C231/00—Preparation of carboxylic acid amides
- C07C231/02—Preparation of carboxylic acid amides from carboxylic acids or from esters, anhydrides, or halides thereof by reaction with ammonia or amines
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/58—Preparation of carboxylic acid halides
- C07C51/60—Preparation of carboxylic acid halides by conversion of carboxylic acids or their anhydrides or esters, lactones, salts into halides with the same carboxylic acid part
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2602/00—Systems containing two condensed rings
- C07C2602/02—Systems containing two condensed rings the rings having only two atoms in common
- C07C2602/04—One of the condensed rings being a six-membered aromatic ring
- C07C2602/08—One of the condensed rings being a six-membered aromatic ring the other ring being five-membered, e.g. indane
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/08—Stabilised against heat, light or radiation or oxydation
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/24—Crystallisation aids
Abstract
The invention relates to a polylactic acid composition containing an amide nucleating agent and a preparation method thereof, belonging to the technical field of polylactic resin, wherein the raw materials comprise the amide nucleating agent, an antioxidant, a hydrolysis-resistant agent and L-polylactic acid, and the polyamide nucleating agent is prepared by mixing through a high-speed mixer and extruding and granulating through double screws; in the preparation process, trimesic acid and triphosgene are used as raw materials to prepare trimesoyl chloride, the trimesoyl chloride and aminoindan are subjected to substitution reaction, and the reaction product is subjected to post-treatment to obtain the amide-type nucleating agent; the amide-type nucleating agent has good compatibility with L-polylactic acid, and can improve the tensile strength of the composition; the molecular structure of the polylactic acid composition is highly symmetrical by taking a benzene ring as a center, has stable chemical properties, and can endow the polylactic acid composition with better heat resistance; the amide nucleating agent contains a large amount of amide groups which can form hydrogen bonds with polylactic acid molecules, and can quickly form crystal nuclei in the polylactic acid, thereby achieving the purpose of improving the crystallization rate and the crystallinity of the polylactic acid.
Description
Technical Field
The invention belongs to the technical field of polylactic acid resin, and particularly relates to a polylactic acid composition containing an amide nucleating agent and a preparation method thereof.
Background
Polylactic acid is a polyester, and lactic acid is a biomonomer that occurs in nature. The polylactic acid is thermoplastic, can be processed by the production process of common plastics, such as films, sheets and fibers, and is a bio-based degradable material with wide application prospect.
However, polylactic acid has a disadvantage of poor heat resistance, and the glass transition temperature of polylactic acid products obtained by various molding methods is only 55 to 65 ℃ and is difficult to satisfy practical use. After crystallization, the heat distortion temperature can be increased to more than 100 ℃, but although polylactic acid is a crystalline polymer, the polylactic acid is difficult to be fully crystallized in the actual molding process because the crystallization rate is slow.
The nucleating agent is an additive capable of promoting matrix crystallization through a nucleating effect, and can improve the nucleation density by reducing the surface free energy barrier required during the nucleation of the polylactic acid, thereby playing roles in refining the grain size, accelerating the crystallization rate, and improving the mechanical properties of the product, such as transparency, heat-resistant stability, tensile strength, flexural modulus and the like.
In many product fields, the required product does not need to be transparent, but has higher requirement on heat resistance and higher heating speed in the processing process, and in order to balance the heat resistance and the crystallization rate of the product, the invention provides a polylactic acid composition containing an amide-type nucleating agent and a preparation method thereof.
Disclosure of Invention
The invention aims to provide a polylactic acid composition containing an amide nucleating agent and a preparation method thereof, and solves the technical problem of how to improve the heat resistance and the crystallization effect of a polylactic acid material.
The purpose of the invention can be realized by the following technical scheme:
a polylactic acid composition containing an amide nucleating agent comprises the following raw materials in percentage by weight: 0.3 to 3 percent of amide nucleating agent, 0.2 to 1.5 percent of antioxidant, 0.1 to 1.5 percent of anti-hydrolysis agent and the balance of L-polylactic acid to be supplemented to 100 percent;
the amide-type nucleating agent has the following structural formula:
further, the amide-type nucleating agent is prepared by the following steps:
step A1: firstly, mixing and dissolving trimesic acid and triphosgene in an ethyl acetate solvent, then dropwise adding an initiator, heating to 60-65 ℃, and carrying out heat preservation reaction for 6-8 hours to synthesize a trimesoyl chloride solution;
the reaction process is as follows:
step A2: dissolving aminoindan in an ethyl acetate solvent, then dropwise adding the trimesoyl chloride solution obtained in the step A1, strictly controlling the temperature of a reaction system to be 20-60 ℃ in the dropwise adding process, heating to 75-78 ℃ after dropwise adding is finished, stopping heating after reacting for 6-10h, cooling to below 60 ℃, performing suction filtration to obtain a filter cake, and crushing the filter cake to obtain a crude nucleating agent;
step A3: and washing the crude product of the nucleating agent by using boiling water, performing suction filtration, washing by using a sodium hydroxide solution with the mass fraction of 40%, performing suction filtration, washing a filter cake by using clear water, performing suction filtration, and drying to obtain the amide-type nucleating agent.
Further, in the step A1, the molar ratio of the trimesic acid to the triphosgene to the initiator is 1:3:1.5, and the initiator is N, N-dimethylformamide.
Further, in step a2, the molar ratio of aminoindan to trimesoyl chloride is 3: 1; the aminoindane is preferably any one of 1-aminoindane and 5-aminoindane.
Further, the antioxidant is any one of antioxidant 168 or antioxidant 1010.
Further, the hydrolysis-resistant agent is any one of monomer carbodiimide or polymeric carbodiimide.
Further, the L-polylactic acid is commercially available L-polylactic acid, and the L-lactic acid content is more than 90%.
A preparation method of a polylactic acid composition containing an amide nucleating agent specifically comprises the following steps:
step S1, adding all the formula raw materials into a high-speed mixer, and stirring for 10min to obtain a mixture;
and step S2, adding the mixture into a double-screw extruder for granulation, wherein the melting temperature is 180-230 ℃, the length-diameter ratio of the screw is more than 30, extruding and granulating after melting and plasticizing, and drying to obtain the polylactic acid composition capable of being rapidly crystallized.
The invention has the beneficial effects that:
the method comprises the steps of firstly reacting trimesic acid with triphosgene under the conditions of a solvent and an initiator to generate trimesoyl chloride, then carrying out substitution reaction on the trimesoyl chloride and aminoindan, carrying out post-treatment such as washing and suction filtration on a reaction product to obtain an amide-type nucleating agent, directly dripping the trimesoyl chloride serving as an intermediate product into an ethyl acetate solution of the aminoindan without separating the trimesoyl chloride from the solvent in the reaction process, and having simple and easy operation process, simple post-treatment and low cost, and suitability for industrial production;
the amide-type nucleating agent is an organic micromolecule, has good compatibility with L-polylactic acid, is beneficial to the uniform distribution of the components of the polylactic acid composition, and can improve the tensile strength of the composition; the molecular structure of the amide-type nucleating agent is highly symmetrical by taking a benzene ring as a center, has stable chemical properties, and can endow the polylactic acid composition with better heat resistance after the L-polylactic acid is melted and blended; the amide nucleating agent also contains three amide groups in the molecule, a large number of amide groups can form hydrogen bonds with polylactic acid molecules, and can quickly form crystal nuclei in the polylactic acid, so that the aim of improving the crystallization rate and the crystallinity of the polylactic acid is fulfilled.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
An amide-type nucleating agent is prepared by the following steps:
step A1: firstly, mixing and dissolving 1mol of trimesic acid and 3mol of triphosgene in 15mol of ethyl acetate solvent, then dropwise adding 1.5mol of N, N-dimethylformamide, heating to 60 ℃, and carrying out heat preservation reaction for 6.5 hours to synthesize a trimesoyl chloride solution;
step A2: dissolving 3mol of 1-aminoindane in 5mol of ethyl acetate solvent, then dropwise adding the trimesoyl chloride solution obtained in the step A1, strictly controlling the temperature of a reaction system to be 30 ℃ in the dropwise adding process, heating to 75 ℃ after the dropwise adding is finished, stopping heating after the reaction is carried out for 7 hours, cooling to 55 ℃, carrying out suction filtration to obtain a filter cake, and crushing the filter cake to obtain a crude nucleating agent;
the reaction process is as follows:
step A3: and washing the crude product of the nucleating agent by using boiling water, performing suction filtration, washing by using a sodium hydroxide solution with the mass fraction of 40%, performing suction filtration, washing a filter cake by using clear water, performing suction filtration, and drying to obtain the amide-type nucleating agent.
Example 2
An amide-type nucleating agent is prepared by the following steps:
step A1: firstly, mixing and dissolving 1mol of trimesic acid and 3mol of triphosgene in 15mol of ethyl acetate solvent, then dropwise adding 1.5mol of N, N-dimethylformamide, heating to 65 ℃, and carrying out heat preservation reaction for 8 hours to synthesize a trimesoyl chloride solution;
step A2: dissolving 3mol of 5-aminoindane in 5mol of ethyl acetate solvent, then dropwise adding the trimesoyl chloride solution obtained in the step A1, strictly controlling the temperature of the reaction system to be 50 ℃ in the dropwise adding process, heating to 77 ℃ after the dropwise adding is finished, stopping heating after the reaction is carried out for 10 hours, cooling to 40 ℃, carrying out suction filtration to obtain a filter cake, and crushing the filter cake to obtain a crude nucleating agent;
the reaction process is as follows:
step A3: and washing the crude product of the nucleating agent by using boiling water, performing suction filtration, washing by using a sodium hydroxide solution with the mass fraction of 40%, performing suction filtration, washing a filter cake by using clear water, performing suction filtration, and drying to obtain the amide-type nucleating agent.
Examples 3 to 8
A polylactic acid composition is prepared by the following steps:
step S1, respectively weighing L-polylactic acid, a nucleating agent, an antioxidant 1010 and polycarbodiimide according to the formula data shown in the following table 1, adding all the raw materials into a high-speed mixer, and stirring for 10min to obtain a mixture;
and step S2, adding the mixture into a double-screw extruder for granulation, wherein the melting temperature is 210 ℃, the length-diameter ratio of a screw is 35, extruding and granulating after melting and plasticizing, and drying to obtain the polylactic acid composition.
Comparative examples 1 to 2
A polylactic acid composition is prepared by the following steps:
step S1, respectively weighing L-polylactic acid, an antioxidant 1010 and polycarbodiimide according to the formula data shown in the following table 1, adding all the raw materials into a high-speed mixer, and stirring for 10min to obtain a mixture;
and step S2, adding the mixture into a double-screw extruder for granulation, wherein the melting temperature is 220 ℃, the length-diameter ratio of the screw is 35, extruding and granulating after melting and plasticizing, and drying to obtain the polylactic acid composition.
TABLE 1
In table 1, L-polylactic acid 175 was produced by Total Corbion, and its D body/L body mass was 1/99; l-polylactic acid 175 produced by Total Corbion, having a D body/L body mass of 4/96; antioxidant 1010 is manufactured by basf corporation; the polycarbodiimide is a polycarbodiimide hydrolysis resistant agent Stabaxol P produced by Rhine company; the nucleating agent (1) and the nucleating agent (2) were amide-type nucleating agents obtained in examples 1 to 2, respectively.
The polylactic acid compositions prepared in examples 3 to 8 and comparative examples 1 to 2 were respectively charged into molds having a nozzle temperature of 220 ℃ and a temperature of 85 ℃ and were kept for 20 seconds to prepare standard sample bars. And then testing the crystallization enthalpy, the heat distortion temperature and the tensile strength of the standard sample strip, wherein the specific testing method comprises the following steps:
and (3) determination of crystallization enthalpy: adopting a German Netzsch differential scanning calorimeter DSC 3500, operating according to GB/T19466.3-2004 'Plastic differential scanning calorimetry' standard, setting the cooling speed at 5 ℃/min, obtaining a crystallization enthalpy value through integral calculation, wherein the larger the crystallization enthalpy value is, the more effective the nucleating agent is, and the larger the crystallization rate and the crystallinity of the prepared polylactic acid are;
measurement of Heat distortion temperature: testing is carried out according to GB/T1634-1979 test method of plastic bending load thermal deformation temperature (thermal deformation temperature for short);
and (3) measuring the tensile strength: testing is carried out according to GB/T1040 + 1992 test method for tensile properties of plastics;
the specific test data are shown in table 2 below.
TABLE 2
As is apparent from the test data of Table 2, the enthalpy of crystallization values of the polylactic acid compositions prepared in examples 3 to 8 are 2 to 3 times the enthalpy of crystallization values of the polylactic acid compositions prepared in comparative examples 1 to 2, indicating that the crystallization rate and the crystallinity of the polylactic acid can be effectively increased by adding the amide-type nucleating agent prepared according to the present invention; and the polylactic acid compositions prepared in examples 3 to 8 can endure higher heat distortion temperature and have more excellent tensile strength than the polylactic acid compositions prepared in comparative examples 1 to 2.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.
Claims (8)
1. A polylactic acid composition containing an amide-type nucleating agent, which is characterized in that: comprises the following raw materials in percentage by weight: 0.3-3% of amide nucleating agent, 0.2-1.5% of antioxidant, 0.1-1.5% of hydrolysis-resistant agent and the balance of L-polylactic acid;
the amide-type nucleating agent has the following structural formula:
the amide-type nucleating agent is prepared by the following steps:
step A1: firstly, mixing and dissolving trimesic acid and triphosgene in an ethyl acetate solvent, then dropwise adding an initiator, heating to 60-65 ℃, and carrying out heat preservation reaction for 6-8 hours to obtain a trimesoyl chloride solution;
step A2: dissolving aminoindan in an ethyl acetate solvent, then dropwise adding the trimesoyl chloride solution obtained in the step A1, heating to 75-78 ℃ after dropwise adding, reacting for 6-10h, stopping heating, cooling, performing suction filtration to obtain a filter cake, and crushing the filter cake to obtain a crude nucleating agent;
step A3: and washing the crude nucleating agent, filtering to remove impurities, and drying to obtain the amide nucleating agent.
2. The polylactic acid composition containing an amide-type nucleating agent according to claim 1, wherein: in the step A1, the molar ratio of the trimesic acid to the triphosgene to the initiator is 1:3:1.5, and the initiator is N, N-dimethylformamide.
3. The polylactic acid composition containing an amide-type nucleating agent according to claim 1, wherein: the molar ratio of aminoindan to trimesoyl chloride in step a2 is 3:1.
4. The polylactic acid composition containing an amide-type nucleating agent according to claim 1, wherein: the antioxidant is one of antioxidant 168 or antioxidant 1010.
5. The polylactic acid composition containing an amide-type nucleating agent according to claim 1, wherein: the hydrolysis-resistant agent is any one of monomer carbodiimide or polymeric carbodiimide.
6. The polylactic acid composition containing an amide-type nucleating agent according to claim 1, wherein: the L-polylactic acid has an L-lactic acid content of more than 90%.
7. The method for preparing the polylactic acid composition containing the amide-type nucleating agent according to claim 1, which comprises the following steps:
step S1, adding all the formula raw materials into a high-speed mixer, and stirring for 10min to obtain a mixture;
and step S2, adding the mixture into a double-screw extruder, extruding and granulating after melting and plasticizing, and drying to obtain the polylactic acid composition.
8. The method for preparing a polylactic acid composition containing an amide-type nucleating agent as claimed in claim 7, wherein the melting temperature is 180-230 ℃, and the length-diameter ratio of the screw of the twin-screw extruder is greater than 30.
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| CN103554856B (en) * | 2013-10-22 | 2015-10-21 | 山西省化工研究所（有限公司） | A kind of nucleating agent in polylactic acid production composition and application thereof |
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