CN117777685A - High-low temperature resistant crystallization straw material, preparation method and application - Google Patents

Abstract

The invention belongs to the technical field of environment-friendly materials, and particularly relates to a high-low temperature resistant crystallization straw material, a preparation method and application thereof; the crystallization straw material preparation raw materials comprise the following components in parts by weight: 40-60 parts of polylactic acid, 5-30 parts of polybutylene succinate, 1-5 parts of compatilizer, 15-25 parts of talcum powder, 0.1-0.5 part of chain extender, 0.1-0.4 part of lubricant, 0.1-1 part of nucleating agent and 1-5 parts of plasticizer; the preparation method comprises the following steps: polylactic acid, polybutylene succinate, a compatilizer, a plasticizer, talcum powder, a chain extender, a lubricant and a nucleating agent are mixed uniformly and then added into an extruder to obtain a high-low temperature resistant crystallization straw material through melting, extrusion and granulation; under the condition of low PBS content, the invention prepares the high temperature resistant crystallization straw with non-deforming crystallization by utilizing the synergistic effect of the PBS-g-GMA compatilizer and the organic nucleating agent. In addition, the cold resistance of the plasticizer is utilized, the system compatibility is improved by combining PBS-g-GMA, the low temperature resistance of the crystallization straw is synergistically improved, and the high temperature resistance of the crystallization straw is endowed with good low temperature resistance.

Description

High-low temperature resistant crystallization straw material, preparation method and application

Technical Field

The invention relates to the technical field of environment-friendly materials, in particular to a high-low temperature resistant crystallization straw material, a preparation method and application thereof.

Background

Polylactic acid (PLA) has excellent mechanical properties and becomes the first choice material for the biodegradable suction tube. Because of the slow crystallization speed of the PLA which is not specially modified, the heat-resistant temperature of the directly formed PLA straw is less than or equal to 55 ℃, and the PLA straw cannot be used in the heat-resistant field, and even cannot meet the conventional transportation requirement.

At present, a downstream manufacturer mainly adopts a drying tunnel crystallization mode to improve the crystallinity of the PLA straw, so that the heat-resistant temperature of the PLA straw is more than or equal to 75 ℃, but the process is easy to cause deformation of the straw, and the use of consumers is seriously affected. In order to solve the problem of deformation of the straw during crystallization, a main method is to add PBS with excellent heat resistance so that the straw does not deform during crystallization. Firstly, the PBS itself is not thoroughly purified in the synthesis process, so that the total migration amount of the high-proportion PBS content straw in 50% ethanol solution often exceeds the limit value in GB4806.7-2016, and the health and safety of consumers are threatened. Second, the price of PBS is high, making the cost of PLA crystallization pipettes with high PBS content unacceptable to downstream manufacturers. However, the content of PBS in the straw is reduced, the crystallization straw is obviously deformed in the crystallization process, and the hand pinching cracking rate of less than or equal to 10 percent after PLA crystallization straw is frozen for four hours at minus 15 ℃ by downstream factories is not satisfied.

In summary, the current crystallization straw with low PBS content is difficult to meet the requirements of straw crystallization invariance and low temperature resistance.

Disclosure of Invention

Aiming at the defects of the prior art, the aim of the invention can be realized by the following technical scheme:

the high-low temperature resistant crystallization straw material comprises the following preparation raw materials in parts by weight:

preferably, the melt index of the polybutylene succinate is 5-15g/10min under the condition of 190 ℃ and 2.16 kg.

Preferably, the melt index of the polylactic acid under the condition of 2.16kg at 190 ℃ is 5-10g/10min, and the polylactic acid is selected from PLLA with high optical purity in the left-hand direction, and the D-content of the polylactic acid is less than 1.

Preferably, the talc is 1250-5000 mesh in number.

Preferably, the nucleating agent is hydrazide, amide or organic salt, wherein the hydrazide is TMC-300 of Shanxi reaction institute, the amide is TMC-328 of Shanxi reaction institute, and the organic salt is Hyperform (R) HPN-68L; the chain extender is anhydride, oxazoline and epoxide, wherein the anhydride is pyromellitic anhydride, the oxazoline is 2, 2-bis (2-oxazoline) and the epoxide compound is basf ADR4468.

Preferably, the lubricant is one or more of dipentaerythritol, solid paraffin and ethylene bisstearamide; the plasticizer is one or more of dioctyl adipate, triethyl citrate and diisooctyl cyclohexane dicarboxylate;

preferably, the compatilizer is PBS-g-GMA, and the preparation of the PBS-g-GMA comprises the following steps: drying the poly (butylene succinate), uniformly mixing the poly (butylene succinate), the glycidyl methacrylate and the initiator to obtain a mixture after the drying is finished, adding the mixture into an extruder, extruding and granulating to obtain a grafted and modified product PBS-g-GMA;

the addition ratio of the polybutylene succinate to the glycidyl methacrylate to the initiator is as follows: 70-90:10-20:0.1-5;

the extruder adopts a double-screw extruder, the extrusion temperature of the extruder is 140-160 ℃, and the rotating speed of the extruder is 60r/min.

Preferably, the initiator is one or more of acrylamide and dibenzoyl peroxide.

Preferably, the preparation method of the high-low temperature resistant crystallization straw material comprises the following steps: the polylactic acid, the polybutylene succinate, the compatilizer, the plasticizer, the talcum powder, the chain extender, the lubricant and the nucleating agent are poured into a mixer to be mixed to obtain a mixture, and then the mixture is added into an extruder to be melted, extruded and granulated, thus obtaining the high-low temperature resistant crystallization straw material;

the extruder adopts a double-screw extruder, the extrusion temperature of the extruder is 160-200 ℃, and the rotation speed of the extruder is 200-400 rpm.

Preferably, the high-low temperature resistant crystallization straw material prepared by the preparation method is applied to the preparation of straw products.

The invention has the beneficial effects that:

(1) Under the condition of low-content PBS, the invention improves the compatibility of PBS and PLA by using PBS-g-GMA, has better effect of supporting PLA not to deform in the initial stage of crystallization than pure PBS, and combines an organic nucleating agent and a plasticizer to synergistically improve the crystallization rate of PLA.

(2) The pure PBS toughens the PLA crystallization straw, and the requirement that the hand-pinching cracking rate is less than or equal to 10 percent after the crystallization straw is frozen for four hours at minus 15 ℃ is not met, in the patent, the cold resistance of the plasticizer is utilized, the PBS-g-GMA is adopted to improve the compatibility of the PBS and the PLA to cooperatively improve the freezing resistance of the crystallization straw, so that the crystallization straw meets the requirement that the hand-pinching cracking rate is less than or equal to 10 percent after the crystallization straw is frozen for four hours at minus 15 ℃.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the prior art, the drawings that are required for the description of the embodiments or the prior art will be briefly described, and it will be apparent to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a diagram showing a suction pipe in an embodiment of the present invention after crystallization without deformation;

FIG. 2 is a diagram showing the suction pipe slightly deformed after crystallization in accordance with the embodiment of the present invention;

FIG. 3 is a diagram showing the embodiment of the present invention when the straw is severely deformed after crystallization.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In some embodiments of the invention, the PBS stock may include, but is not limited to, one or more of BG-2112 from Anhui Sangusan Biotechnology, inc., PTT chemical FZ91PM, TH803S from Sinkiang Lanshan Tuohe, inc.

The PLA in the invention has a melt index of 3-12g/10min at 190 ℃ and 2.16kg and is selected from L-high optical purity PLLA. In some embodiments of the invention, examples of PLA include, but are not limited to, one or more of revole 190 from Zhejiang, FY801 from Anhuifengyuan, L175 from Total cobion, and the like.

In some embodiments of the invention, the talc is 1250-5000 mesh, examples of which include, but are not limited to, one or more of Guilin ultra fine talc GH602C (1250 mesh), longguan Osmanthus tablet talc (3000 mesh), xuping powder BHS-8860 talc (5000 mesh).

The forming mode of the suction pipe for measuring the deformation degree of the suction pipe in the crystallization process and the freezing resistance of the suction pipe in the invention is as follows: pouring the prepared crystallization straw material into a straw machine for molding processing to prepare straws with gram weight, length and inner diameter of 25+/-0.2 g, 22+/-0.2 cm and 11.2+0.2mm respectively. The temperatures of the first zone, the second zone, the third zone, the first die head and the second die head of the straw machine are 180 ℃, 185 ℃, 190 ℃ and 200 ℃ respectively.

And (3) placing the prepared straw in a baked material with the constant temperature of 95 ℃ in advance for annealing for 5min, placing the annealed crystallization straw at room temperature for cooling for 24h, then placing the crystallization straw in a refrigerator with the constant temperature of minus 15 ℃ in advance for freezing for four hours, immediately removing the straw by hands after freezing for four hours, and recording the freezing cracking rate of the straw.

In each of the examples and comparative examples, the main raw material sources were as follows:

TABLE 1 raw materials and sources

Example 1

(1) Preparation of PBS-g-GMA-1 masterbatch

100 parts of PBS, 10 parts of GMA and 1 part of dibenzoyl peroxide (BPO) are uniformly mixed according to parts by weight, and then a double-screw extruder is used for reaction blending, extrusion and granulation to prepare a modified product PBS-g-GMA. The temperature of the double-screw extruder is 130-160 ℃, the rotating speed of the main machine is 80-150 rpm, and the temperature of the cooling water tank is 20-40 ℃.

(2) Preparation of high-low temperature resistant crystallization straw material with low PBS content

The modified PBS-g-GMA and the formula components in the table 2 are taken as raw materials, and the raw materials in the table 2 are referenced for use, and the preparation method is as follows:

a. firstly, putting PBS-g-GMA master batch, PBS resin, gao Guangchun PLA resin and talcum powder into an oven at 80 ℃ for drying for 4 hours;

b. firstly, adding the dried PBS resin, PBS-g-GMA master batch, high-gloss pure PLA resin and liquid plasticizer into a high-speed mixer for uniform mixing, then adding talcum powder for uniform mixing again, and finally adding powder auxiliary agents such as chain extender, lubricant and nucleating agent for uniform mixing. And adding the uniformly mixed materials into a feeding bin of a double-screw extruder for melt blending, extruding and granulating, and then placing the manufactured particles into an oven at 80 ℃ for drying for 4 hours to finally prepare the high-low temperature resistant crystallization suction pipe material with low PBS content. The temperature of the twin-screw extruder was 190℃and the rotational speed was 350 revolutions per minute.

Example 2

(1) Preparation of PBS-g-GMA master batch

100 parts of PBS, 15 parts of GMA and 2 parts of Acrylamide (AM) are uniformly mixed according to parts by weight, and then a double-screw extruder is used for reaction blending, extrusion and granulation to prepare a modified product PBS-g-GMA. The temperature of the double-screw extruder is 130-160 ℃, the rotating speed of the main machine is 80-150 rpm, and the temperature of the cooling water tank is 20-40 ℃.

(2) Preparation of high-low temperature resistant crystallization straw material with low PBS content

PBS-g-GMA obtained by modification and the formulation components in Table 2 are taken as raw materials, and the PBS content and the high and low temperature resistant crystallization suction pipe materials are prepared according to the method of (2) in the example 1 by referring to the raw material dosage in the table 2, except that the PBS-g-GMA master batch obtained in the example 1 is replaced by the PBS-g-GMA master batch obtained in the example 2, the nucleating agent obtained in the example 1 is removed, and the formulation and the raw material dosage in the table 2 are different. Further, the temperature of the twin-screw extruder was 180℃and the rotational speed was 260 revolutions per minute.

Example 3

(1) Preparation of PBS-g-GMA master batch

100 parts of PBS, 10 parts of GMA and 0.5 part of initiator acrylamide are uniformly mixed according to parts by weight, and then a double-screw extruder is used for reaction blending, extrusion and granulation to prepare a modified product PBS-g-GMA. The temperature of the double-screw extruder is 130-160 ℃, the rotating speed of the main machine is 80-150 rpm, and the temperature of the cooling water tank is 20-40 ℃.

(2) Preparation of high-low temperature resistant crystallization straw material with low PBS content

PBS-g-GMA obtained by modification and formulation components in Table 2 are taken as raw materials, and a PBS content and high and low temperature resistant crystallization catheter material is prepared according to the method of (2) in example 1 with reference to the raw material dosage in Table 2, except that PBS-g-GMA master batch obtained in example 1 is replaced with PBS-g-GMA master batch obtained in example 3, nucleating agent and plasticizer in example 1 are removed, chain extender ADR4468 is replaced with XY4350, and the formulation and raw material dosage in Table 2 are different. Further, the temperature of the twin-screw extruder was 185℃and the rotational speed was 300 revolutions per minute.

Comparative example 1

Crystalline pipettes were prepared as in (2) of example 1, starting with the formulation components of table 2 and with reference to the amounts of the raw materials in table 2, except that the PBS-g-GMA compatibilizer, plasticizer and nucleating agent of example 1 were removed and the formulations and amounts of the raw materials of table 2 were varied. Further, the temperature of the twin-screw extruder was 170℃and the rotational speed was 260 revolutions per minute.

Comparative example 2

Crystalline straw materials were prepared in the same manner as in (2) of example 1, except that the plasticizer and nucleating agent of example 1 were removed, the chain extender ADR4468 was replaced with XY4350, and the formulation and raw material amounts of table 2 were different, using the formulation components of table 2 as raw materials, and referring to the raw material amounts of table 2. Further, the temperature of the twin-screw extruder was 190℃and the rotational speed was 400 rpm.

Comparative example 3

Crystalline pipettes were prepared as in (2) of example 1, starting with the formulation components of table 2 and with reference to the amounts of the raw materials in table 2, except that the PBS-g-GMA compatibilizer, plasticizer and nucleating agent of example 1 were removed and the formulations and amounts of the raw materials of table 2 were varied. Further, the temperature of the twin-screw extruder was 185℃and the rotational speed was 350 revolutions per minute.

TABLE 2 raw materials and amounts (g) in examples 1-3 and comparative examples 1-3

The crystalline pipette materials obtained in examples 1 to 3 and comparative examples 1 to 3 were subjected to extrusion molding processing by a pipette machine to prepare pipettes having gram weights, lengths and inner diameters of 25.+ -. 0.2g, 22.+ -. 0.2cm and 11.2.+ -. 0.2mm, respectively, and temperatures of the first zone, the second zone, the third zone, the first die and the second die of the pipette machine were 180 ℃, 185 ℃, 190 ℃ and 200 ℃, respectively. And (3) placing the prepared straw into a baked material with the constant temperature of 95 ℃ in advance for annealing for 5 minutes to obtain the crystallization heat-resistant straw. The performance test parameters and corresponding test methods of the crystalline pipette materials and pipettes obtained in each example and comparative example are as follows:

1. melt index test: the melt index of the crystalline sorbent material was tested according to ISO1133 at 190℃at 2.16kg;

2. deformation degree test of crystallization straw in crystallization process: the degree of deformation of the pipettes during crystallization for each of the comparative examples and comparative examples is largely divided into no deformation (as in fig. 1), slight deformation (as in fig. 2) and severe deformation (as in fig. 3).

3. Freezing test of crystallization straw: the crystallized straws were placed at room temperature for 24 hours, then placed in a refrigerator set at a constant temperature of minus 15 ℃ in advance, frozen for 4 hours, immediately pinched by hand, and the freezing cracking rate of the straws was recorded, and 50 straws were taken for each of the examples and comparative examples to be frozen.

4. Testing the heat-resistant temperature of the crystallization straw: firstly, placing 50 pieces of solid glass with the diameter of 7mm into a kettle with proper amount of water, then heating the kettle to a set temperature, stirring glass microspheres by using a crystallization straw after the temperature is constant, and after stirring, ensuring that the crystallization straw has no obvious deformation, so that the straw can bear the set temperature of the kettle.

The following table shows the test results.

TABLE 3 results of Performance test of the products of examples 1-3 and comparative examples 1-3

As can be seen from comparative examples 1-3 and examples 1-3, the straws after crystallization have a heat resistant temperature of > 75℃, which meets the needs of the straw in the milk tea industry. However, when the PBS content is less than 25wt%, the straw will not only deform during crystallization, but also the pure PBS toughens the crystallized straw material, and the frozen cracking rate of the straw after crystallization is more than 10%, which is not acceptable to downstream manufacturers. The low PBS content high-low temperature resistant crystallization straw material prepared by the invention firstly utilizes PBS-g-GMA to improve the compatibility between PLA and PBS, plays a better role in supporting the straw to avoid deformation in the crystallization process than pure PBS, and simultaneously utilizes nucleating agent and plasticizer to cooperatively improve the crystallization rate of PLA so as to achieve the purpose that the straw is not deformed in the crystallization process under the condition of adding low PBS content. Secondly, the PBS-g-GMA is utilized to improve the compatibility between PLA and PBS and the cold resistance of the plasticizer, so that the freezing cracking rate of the crystallization straw is obviously reduced, the freezing cracking rate of the embodiment 1 and the embodiment 2 is less than or equal to 10, and the requirements of downstream manufacturers are met.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, 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 present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. 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 has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims.

Claims (10)

1. The high-low temperature resistant crystallization straw material is characterized by comprising the following preparation raw materials in parts by weight:

2. the high and low temperature resistant crystallization straw material according to claim 1, wherein the polybutylene succinate has a melt index of 5-15g/10min at 190 ℃ under 2.16kg conditions.

3. The high and low temperature resistant crystallization straw material according to claim 1, wherein the melt index of the polylactic acid is 5-10g/10min at 190 ℃ under 2.16kg conditions, and the polylactic acid is selected from the group consisting of l-high optical purity PLLA, and the D-content thereof is%o < 1.

4. The high and low temperature resistant crystallization straw material according to claim 1, wherein the talc has a mesh size of 1250-5000 mesh.

5. The high and low temperature resistant crystallization straw material according to claim 1, wherein the nucleating agent is hydrazides, amides or organic salts, wherein the hydrazides are TMC-300 of Shanxi reaction sites, the amides are TMC-328 of Shanxi reaction sites, and the organic salts are Hyperform (R) HPN-68L; the chain extender is anhydride, oxazoline and epoxide, wherein the anhydride is pyromellitic anhydride, the oxazoline is 2, 2-bis (2-oxazoline) and the epoxide compound is basf ADR4468.

6. The high and low temperature resistant crystallization straw material according to claim 1, wherein the lubricant is one or more of dipentaerythritol, paraffin wax, and ethylene bis stearamide; the plasticizer is one or more of dioctyl adipate, triethyl citrate and diisooctyl cyclohexane dicarboxylate.

7. The high and low temperature resistant crystallization straw material according to claim 1, wherein the compatibilizer is PBS-g-GMA, and the preparation of the PBS-g-GMA comprises the following steps: drying the poly (butylene succinate), uniformly mixing the poly (butylene succinate), the glycidyl methacrylate and the initiator to obtain a mixture after the drying is finished, adding the mixture into an extruder, extruding and granulating to obtain a grafted and modified product PBS-g-GMA;

the addition ratio of the polybutylene succinate to the glycidyl methacrylate to the initiator is as follows: 70-90:10-20:0.1-5;

the extruder adopts a double-screw extruder, the extrusion temperature of the extruder is 140-160 ℃, and the rotating speed of the extruder is 60r/min.

8. The high and low temperature resistant crystallization straw material according to claim 7, wherein the initiator is one or more of acrylamide and dibenzoyl peroxide.

9. A method for preparing a high and low temperature resistant crystallization straw material according to any one of claims 1-8, wherein the preparation method comprises the steps of: the polylactic acid, the polybutylene succinate, the compatilizer, the plasticizer, the talcum powder, the chain extender, the lubricant and the nucleating agent are poured into a mixer to be mixed to obtain a mixture, and then the mixture is added into an extruder to be melted, extruded and granulated, thus obtaining the high-low temperature resistant crystallization straw material;

the extruder adopts a double-screw extruder, the extrusion temperature of the extruder is 160-200 ℃, and the rotation speed of the extruder is 200-400 rpm.

10. The use of the high and low temperature resistant crystalline straw material prepared by the preparation method of claim 9 in the preparation of straw articles.