Polyester composition and molded product containing polyester composition

Abstract

The present invention provides a polyester composition comprising a thermoplastic biodegradable polyester and a PBSN polymer. The polyester composition has good biodegradability, mechanical properties and heat resistance. The invention also provides a molded product containing the polyester composition.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and particularly to a product that can be in contact with edible materials. Background Art

[0002] In order to protect the ecological environment, degradable tableware is usually used in the catering industry, and among them, thermoplastic biodegradable polyesters with large usage include. PLA is a known polymer that can be used as a substrate for tableware, such as straws. Due to the poor heat resistance of PLA, it cannot be in contact with high-temperature foods. Currently, the PLA used to prepare straws is usually a secondary crystalline material to improve its heat resistance. However, the mechanical properties of PLA after secondary crystallization are reduced, the toughness is poor, and it is prone to low-temperature cracking, especially not suitable for use in winter or cold regions in the north. Summary of the Invention

[0003] In view of this, the present invention provides a polymer and a product prepared therefrom that can be in contact with edible materials, which has good mechanical properties, biodegradable properties and heat resistance.

[0004] Unless otherwise specified, the percentage content in the present invention is in mole percentage, and the parts refer to parts by weight.

[0005] In a first aspect, the present invention provides a polyester composition, which comprises:

[0006] (A) 10-70 parts by weight of a thermoplastic biodegradable polyester;

[0007] (B) 10-70 parts by weight of a PBSN polymer.

[0008] The PBSN polymer comprises a polyester main structural unit and a modified unit, and the modified unit comprises a structure of formula (I):

[0009]

[0010] R1 is independently a straight-chain or branched-chain alkylene group with 2-4 carbon atoms;

[0011] R2 is a straight-chain or branched-chain secondary alkylene group with 2-4 carbon atoms.

[0012] In an example of the present invention, in the polyester composition of the present invention, the polyester main structural unit in the PBSN polymer is selected from one or more of PBS, PES, PBA, PET, PBT, PTT, PBAT or PBST, and preferably PBS.

[0013] In one example of the present invention, the thermoplastic biodegradable polyester in the polyester composition of the present invention is selected from one or more of PLA, PLGA, PHA, PBAT, and PCL, preferably PLA and / or PBAT. Preferably, the content of the thermoplastic biodegradable polyester in the polyester composition is 30-60 parts by weight, preferably 40-55 parts by weight.

[0014] In one example of the present invention, the proportion of the modified unit with the structure of formula (I) in the polyester composition of the present invention in the total polyester units of the PBSN polymer is 1-50 mol%, preferably 5-40 mol%;

[0015] Preferably, R2 is the residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol;

[0016] Preferably, R1 is ethylene.

[0017] In one example of the present invention, in the polyester composition of the present invention, the content of the PBSN polymer in the polyester composition is 20-50 parts by weight, preferably 25-40 parts by weight; preferably, the melt index of the PBSN is 0.1-10 g / 10 min.

[0018] In a second aspect, the present invention provides a molded article that can be in contact with an edible material, and the molded article comprises the polyester composition of the present invention in any of the above technical solutions.

[0019] In one example of the present invention, the above-mentioned molded article of the present invention is selected from one or more of utensils, plates, cups, cup lids, saucers, cup holders, toothpicks, straws, and rods, preferably straws.

[0020] In one example of the present invention, the above-mentioned molded article of the present invention further comprises at least one of the following additives:

[0021] (i) 1-25 parts by weight of a filler, such as talcum powder;

[0022] (ii) 0.01-1 part by weight of a nucleating agent;

[0023] (iii) 0.01-5 parts by weight of other additives, and the other additives are selected from one or more of a dispersant, a lubricant, a compatibilizer, or an antioxidant.

[0024] In a third aspect, the present invention provides an application of a PBSN polymer in the preparation of a product that can be in contact with an edible material, the PBSN polymer comprises a polyester main structural unit and a modified unit, and the modified unit comprises the structure of formula (I):

[0025]

[0026] R1 is independently a straight-chain or branched alkylene group having 2 to 4 carbon atoms;

[0027] R2 is a straight-chain or branched sub-alkylene group having 2 to 4 carbon atoms;

[0028] The proportion of the modified unit containing the structure of formula (I) in the total polyester units of the PBSN polymer is 1-50 mol%;

[0029] The polyester main structural unit is selected from one or more of PBS, PES, PBA, PET, PBT, PTT, PBAT or PBST.

[0030] Preferably, the polyester main structural unit is PBS.

[0031] Preferably, the product that can be in contact with the edible material is a straw.

[0032] Preferably, the proportion of the modified unit in the total polyester units of the PBSN polymer is 5-40 mol%.

[0033] Preferably, R2 is the residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol.

[0034] Preferably, R1 is ethylene. Detailed Description of the Invention

[0035] I. PBSN Polymer

[0036] The PBSN polymer used in the present invention can be referred to in Chinese Patent Application (CN202311583766.2). The preferably used PBSN polymer comprises a polyester main structural unit and a modified unit, and the modified unit comprises the structure of formula (I):

[0037]

[0038] R1 is independently a straight-chain or branched alkylene group having 2 to 4 carbon atoms;

[0039] R2 is a straight-chain or branched sub-alkylene group having 2 to 4 carbon atoms;

[0040] The polyester main structural unit is selected from one or more of PBS, PES, PBA, PET, PBT, PTT, PBAT or PBST; preferably PBS.

[0041] Preferably, the proportion of the modified unit containing the structure of formula (I) in the total polyester units of the PBSN polymer is 1-50 mol%, preferably 5-40 mol%.

[0042] Preferably, R2 is the residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol;

[0043] Preferably, R1 is a succinic acid residue (i.e., ethylene).

[0044] Preferably, the melt index of the polyester is less than 130 g / 10 min according to the ASTM-D1238 standard; preferably, less than 50 g / 10 min.

[0045] The preparation method of the PBSN polymer of the present invention includes:

[0046] Step 1: Subject a primary amino diol (such as 2-amino-1,3-propanediol (i.e., 2-amino in the following table) or 3-amino-1,2-propanediol (i.e., 3-amino in the following table)) and a ring-forming diacid (such as succinic acid or glutaric acid) and / or its corresponding acid anhydride to an amidation reaction to obtain a monomer composition; the monomer composition includes a diol monomer containing an imide ring structure as shown in formula (II):

[0047]

[0048] Step 2: Subject the monomer composition, a diol for polymer synthesis (such as butanediol or ethylene glycol), and a diacid / ester / acid anhydride for polymer synthesis (such as succinic acid, adipic acid, or terephthalic acid) to an esterification / transesterification reaction to obtain a PBSN polymer, wherein the structure of the diol monomer containing an imide ring structure polymerized with the diacid is:

[0049] R3 is a diacid residue for polymer synthesis or a ring-forming diacid residue or a combination of the two; in the specific embodiments of the present invention, R3 is a succinic acid residue.

[0050] II. Thermoplastic biodegradable polyester

[0051] The thermoplastic biodegradable polyester in the present invention is selected from one or more of PLA (polylactic acid or poly(lactic acid)), PLGA (poly(lactic acid-co-glycolic acid)), PHA (polyhydroxyalkanoate), PBAT (copolymer of butylene adipate and butylene terephthalate), PCL (polycaprolactone), preferably PLA and / or PBAT. The polylactic acid used in the examples of the present invention is Haizheng 101, injection molding grade. The PBAT grade used in the examples of the present invention is Blueshan Tunhe 801T.

[0052] III Molded article

[0053] The molded article of the present invention contains the polyester composition of the present invention in any of the above technical solutions.

[0054] The molded articles of the present invention can be prepared by conventional processes in the art. For example, by blow molding or extrusion molding. The molded articles of the present invention that can come into contact with edible materials can be prepared into specifications meeting national standards by conventional methods and equipment.

[0055] In one embodiment of the present invention, the molded articles of the present invention further contain at least one of the following additives:

[0056] (i) 1 - 25 parts by weight of a filler, such as talcum powder;

[0057] (ii) 0.01 - 1 part by weight of a nucleating agent;

[0058] (iii) 0.01 - 5 parts by weight of other auxiliaries, and the other auxiliaries are selected from one or more of dispersants, lubricants, compatibilizers or antioxidants.

[0059] Preferably, the nucleating agent is selected from one or more of nanometer montmorillonite, saturated sodium carboxylates such as sodium succinate, sodium glutarate, sodium hexanoate, sodium 4 - methylpentanoate, adipic acid, aluminum adipate, aluminum tert - butylbenzoate (Al - PTB - BA), aluminum benzoate, potassium benzoate, lithium benzoate, sodium cinnamate, sodium β - naphthoate, LAK301.

[0060] Preferably, the antioxidant is selected from one or more of BASF hindered phenols 1010, 168, phenyl phosphate esters, or aluminum trioxide, and the addition amount is 0.1 - 0.5 parts.

[0061] Preferably, the compatibilizer is selected from one or more of BASF ADR4468, Xiuyuan Chemical Industry KL - 4370, styrene - maleic anhydride copolymer S - MAH, pentaerythritol stearate, and the addition amount is 0.1 - 0.5 parts.

[0062] Preferably, the dispersant is selected from one or more of erucamide, oleamide, polyethylene wax, monoglyceryl stearate, calcium stearate, magnesium stearate, and the addition amount is 0.1 - 0.5 parts.

[0063] Preferably, the lubricant is selected from one or more of paraffin wax, PE wax, silicone oil, silane masterbatch, palm oil, oxidized PE wax, octadecyl stearate, and the addition amount is 0.1 - 0.6 parts.

[0064] The present invention will be further illustrated by specific examples below.

[0065] Synthesis Examples 1 - 6 Synthesis of PBSN Polymer

[0066] Synthesis Example 1

[0067] 911.1 g (10 mol) of the cyclic imide diol compound after vacuum drying, namely 2-amino-1,3-propanediol (i.e., 2-amino in Table 1), and 1180.1 g (10 mol) of 1,4-butanedioic acid were charged into a reaction kettle. At the same time, triphenyl phosphite (heat stabilizer) and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant) were each charged at 100 ppm (relative to the weight of the entire reaction system). Stir at room temperature, and at the same time, use nitrogen to fully displace the air in the kettle. Then, slowly heat up to 120 °C in a nitrogen atmosphere, with a nitrogen flow rate of 150 mL / min, and stir at a constant temperature for 3 h to obtain a polymer with a cyclic imide structure.

[0068] Weigh 173.1 g (1 mol) of the above polymer with a cyclic imide structure, 968.4 (8.2 mol) of butanedioic acid, and 973.1 (10.8 mol) of 1,4-butanediol. Stir and heat to melt in nitrogen. When the temperature reaches 170 °C, add 100 ppm of zinc acetate, and hold the temperature for reaction for 3 h under a negative pressure of -0.03 MPa; then restore to normal pressure, add another 99 g (1.1 mol) of 1,4-butanediol, add 500 ppm of tetrabutyl titanate, and heat up to 230 °C; slowly evacuate to 1 - 2 Torr, and carry out vacuum polycondensation for 6.5 h to obtain PBSN1 polymer.

[0069] Synthesis Example 2

[0070] Except for weighing 519.3 g (3 mol) of the polymer with a cyclic imide structure, 1168.2 g (9.9 mol) of butanedioic acid, and 810 g (9 mol) of 1,4-butanediol, the same as Synthesis Example 1, PBSN2 polymer was prepared.

[0071] Synthesis Example 3

[0072] Except for weighing 692.4 g (4.0 mol) of the polymer with a cyclic imide structure, 626 g (5.3 mol) of butanedioic acid, and 360.4 (4.0 mol) of 1,4-butanediol, the same as Synthesis Example 1, PBSN3 polymer was prepared.

[0073] Synthesis Example 4

[0074] Except that 2-amino-1,3-propanediol in Synthesis Example 1 was replaced with 3-amino-1,2-propanediol (i.e., 3-amino in Table 1), and the molar amount of the polymer with a cyclic imide structure remained unchanged, the other conditions were the same as in Synthesis Example 1, and PBSN4 polymer was prepared.

[0075] Synthesis Example 5

[0076] Except that 2-amino-1,3-propanediol in Synthesis Example 2 was replaced with 3-amino-1,2-propanediol (i.e., 3-amino in Table 1) and the molar amount of the polymer with a cyclic imide structure remained unchanged, other procedures were the same as those in Synthesis Example 2, and PBSN5 polymer was prepared.

[0077] Synthesis Example 6

[0078] Except that 2-amino-1,3-propanediol in Synthesis Example 3 was replaced with 3-amino-1,2-propanediol (i.e., 3-amino in Table 1) and the molar amount of the polymer with a cyclic imide structure remained unchanged, other procedures were the same as those in Synthesis Example 3, and PBSN6 polymer was prepared.

[0079] The PBSN polymers used in the examples are shown in Table 1:

[0080] Table 1

[0081]

[0082] Examples 1-13

[0083] First step, material blending: The raw materials shown in Table 2 (the unit of raw material dosage is parts by weight) were jointly added to a high-speed mixer, the stirring rate was set at 150 r / min, and the stirring time was 3 min. After the blend was stirred evenly, it was taken out for standby.

[0084] Second step, material granulation and extrusion: The above-mentioned uniformly mixed materials were added to a 35-type twin-screw extruder for melt blending and extrusion. The extrusion temperature was set as follows: the temperature of the first section was 100 °C, the second section was 150 °C, the third section was 175 °C, the fourth section was 175 °C, the temperature of the fifth section was 180 °C, the temperature of the plasticizing section was 185 °C, and the temperature of the die head was 190 °C. The extrusion speed was 150 r / min. The extruded and pelletized particles were dried for standby. The drying conditions were 100 °C for 4 h, and the moisture content was <400 ppm.

[0085] Third step, the performance test results are shown in Table 3. Among them, for the mechanical property test, GB / T 1040-79 was referred to; for the heat distortion temperature, GB / T 1634.1-2019 was referred to; for the notched impact strength test, GB / T 1843-2008 was referred to; and for the ethanol migration amount test, GB / T 31604.8 was referred to.

[0086] Table 2

[0087]

[0088] In Table 2: Nucleating agent 1 is selected as nano-montmorillonite with a mesh number of 10,000; nucleating agent 2 is selected as imported nucleating agent LAK301. The antioxidant is a compound of BASF 1010 and 168 (2:1). The compatibilizer is BASF ADR4468. The dispersant is a compound of erucic acid amide and calcium stearate (3:2). The lubricant is PE wax.

[0089] Table 3

[0090]

[0091]

[0092] As can be seen from the above table, the polyester composition of the present invention has good mechanical properties and heat resistance, and is suitable for preparing food utensils such as straws.

[0093] For the above embodiments, all technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A polyester composition comprising: (A) 10 - 70 parts by weight of a thermoplastic biodegradable polyester; (B) 10 - 70 parts by weight of a PBSN polymer; The PBSN polymer comprises a polyester main structural unit and a modified unit, and the modified unit comprises a structure of formula (I): R1 is independently a straight-chain or branched alkylene group having 2 - 4 carbon atoms; R2 is a straight-chain or branched secondary alkylene group having 2 - 4 carbon atoms.

2. The polyester composition according to claim 1, wherein: The polyester main structural unit in the PBSN polymer is selected from one or more of PBS, PES, PBA, PET, PBT, PTT, PBAT or PBST, preferably PBS; Preferably, the thermoplastic biodegradable polyester is selected from one or more of PLA, PLGA, PHA, PBAT, PCL, preferably PLA and / or PBAT; Preferably, the content of the thermoplastic biodegradable polyester in the polyester composition is 30 - 60 parts by weight, preferably 40 - 55 parts by weight.

3. The polyester composition according to any one of claims 1 - 2, wherein: The proportion of the modified unit containing the structure of formula (I) in the total polyester units of the PBSN polymer is 1 - 50 mol%, preferably 5 - 40 mol%; Preferably, R2 is a residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol; Preferably, R1 is an ethylene group.

4. The polyester composition according to any one of claims 1 - 2, the content of the PBSN polymer in the polyester composition is 20 - 50 parts by weight, preferably 25 - 40 parts by weight; Preferably, the melt index of the PBSN is 0.1 - 10 g / 10 min.

5. A molded article that can be in contact with an edible material, the molded article comprising the polyester composition according to any one of claims 1 - 4.

6. The molded article according to claim 5, the molded article is selected from one or more of utensils, plates, cups, cup lids, dishes, cup holders, toothpicks, straws, rods, preferably a straw.

7. The molded article according to any one of claims 5 - 6, the molded article further comprises at least one of the following additives: (i) 1 - 25 parts by weight of a filler, such as talc; (ii) 0.01 - 1 part by weight of a nucleating agent; (iii) 0.01 - 5 parts by weight of other additives, the other additives are selected from one or more of a dispersant, a lubricant, a compatibilizer or an antioxidant.

8. The use of a PBSN polymer in the preparation of a product that can be in contact with an edible material, the PBSN polymer comprises a polyester main structural unit and a modified unit, and the modified unit comprises a structure of formula (I): R1 is independently a straight-chain or branched alkylene group having 2 - 4 carbon atoms; R2 is a straight-chain or branched secondary alkylene group having 2 - 4 carbon atoms; The proportion of the modified unit containing the structure of formula (I) in the total polyester units of the PBSN polymer is 1 - 50 mol%; The polyester main structural unit is selected from one or more of PBS, PES, PBA, PET, PBT, PTT, PBAT or PBST, preferably PBS.

9. The application according to claim 8, wherein the product capable of contacting food materials is a straw.

10. The application according to claim 9, wherein the proportion of the modification unit in the total polyester units of the PBSN polymer is 5-40 mol%; Preferably, R2 is a residue of 2-amino-1,3-propanediol or 3-amino-1,2-propanediol; Preferably, R1 is an ethylene group.

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