阅读说明：本技术 一种亲水改性聚碳酸亚丙酯的制备方法 (Preparation method of hydrophilic modified polypropylene carbonate ) 是由 荣骁 梁胜轲 杜中杰 王武聪 金华 孙佩鑫 缪徐然 邹威 张晨 王洪 于 2021-09-13 设计创作，主要内容包括：本发明涉及一种亲水改性聚碳酸亚丙酯的制备方法,所述的材料用以下方法制备而成：将质量比例的PPC、亲水改性剂、扩链剂混合均匀,经双螺杆挤出机熔融共混造粒,得到亲水PPC颗粒,注塑得到复合材料。制备的亲水改性聚碳酸亚丙酯具有良好的亲水性。(The invention relates to a preparation method of hydrophilic modified polypropylene carbonate, which is prepared by the following steps: uniformly mixing the PPC, the hydrophilic modifier and the chain extender in a mass ratio, carrying out melt blending granulation by a double-screw extruder to obtain hydrophilic PPC particles, and carrying out injection molding to obtain the composite material. The prepared hydrophilic modified polypropylene carbonate has good hydrophilicity.)

1. The hydrophilic modified polypropylene carbonate is prepared by blending polypropylene carbonate (PPC), a hydrophilic modifier and a chain extender uniformly and performing melt extrusion.

2. The hydrophilically modified polypropylene carbonate according to claim 1, characterized in that: the PPC has a melt index of 3-20g/10min (2.16kg, 190 ℃) and a density of 1.27g/cm 3.

3. The hydrophilically modified polypropylene carbonate according to claim 1, characterized in that: the hydrophilic modifier is one of tween 20, tween 21, tween 40 and tween 60.

4. The hydrophilically modified polypropylene carbonate according to claim 1, characterized in that: the chain extender is one of diglycidyl terephthalate, 2- (1, 3-phenylene) -bisoxazoline and diphenylmethane diisocyanate.

5. The method for preparing hydrophilically modified polypropylene carbonate according to claim 1, wherein: the method comprises the following steps: uniformly mixing the PPC, the hydrophilic modifier and the chain extender in a mass ratio, and carrying out melt blending granulation by a double-screw extruder to obtain hydrophilic PPC particles. And adding the prepared hydrophilic modified PPC particles into an injection molding machine, and performing injection molding.

6. The method for preparing hydrophilically modified polypropylene carbonate according to claim 5, wherein: the amount of PPC is 100 parts.

7. The method for preparing hydrophilically modified polypropylene carbonate according to claim 5, wherein: the hydrophilic modifier is used in an amount of 1 to 3 parts, preferably 1 to 2 parts.

8. The method for preparing hydrophilically modified polypropylene carbonate according to claim 5, wherein: the chain extender is used in an amount of 0.3 to 1.5 parts, preferably 0.5 to 1 part.

9. The method for preparing hydrophilically modified polypropylene carbonate according to claim 5, wherein: the processing temperature of the double-screw extruder is 140-160 ℃, and the screw rotating speed of the double-screw extruder is 200-300 rpm.

10. The method for preparing hydrophilically modified polypropylene carbonate according to claim 5, wherein: the temperature of the injection molding machine is 160-170 ℃.

Technical Field

The invention relates to the field of degradable materials, in particular to a preparation method of hydrophilic polypropylene carbonate.

Background

Polypropylene Carbonate (PPC) is a fully degradable aliphatic polycarbonate made of CO₂And propylene oxide. PPC has the advantages of high elongation at break, excellent biocompatibility and no toxicity or harm to human bodies. The advantages make the material attract extensive attention and have wide application in the fields of food packaging, biomedical materials and shape memory materials.

PPC, an aliphatic polyester, is poorly hydrophilic due to its structural properties. And meanwhile, the PPC has poor self thermal stability, and when the processing temperature is higher than 150 ℃, the PPC is subjected to thermal degradation. The thermal degradation mechanism of PPC is divided into two categories: random fracture degradation and unzipping degradation. Random cleavage degradation is the random cleavage of the main chain to form CO₂And unsaturated terminal segments. Unzipping degradation is the back-biting of the terminal hydroxyl groups to form a small cyclic polycarbonate. This results in that if the PPC is hydrophilically modified, the thermal degradation of the PPC is further exacerbated by the addition of hydrophilic modifiers. In order to solve the problems, the invention prepares the hydrophilic modified polypropylene carbonate by adding a hydrophilic modifier and a chain extender and carrying out hydrophilic modification on PPC.

Disclosure of Invention

The invention aims to prepare hydrophilic modified polypropylene carbonate, and the aim of the invention is realized by the following technical scheme:

the invention aims to provide hydrophilic modified polypropylene carbonate, which comprises the following raw material components in parts by weight: PPC: 100 parts of hydrophilic modifier, 1-3 parts of chain extender and 0.3-1.5 parts of chain extender.

Preferably, the PPC has a melt index of 3-20g/10min (2.16kg, 190 ℃ C.), and a density of 1.27g/cm³。

Preferably, the hydrophilic modifier is one of tween 20, tween 21, tween 40 and tween 60.

The chain extender is one of diglycidyl terephthalate, 2- (1, 3-phenylene) -bisoxazoline and diphenylmethane diisocyanate.

The invention also aims to provide a preparation method of the hydrophilic modified polypropylene carbonate, which comprises the following steps:

uniformly mixing the PPC, the hydrophilic modifier and the chain extender in a mass ratio, and carrying out melt blending granulation by a double-screw extruder to obtain hydrophilic PPC particles.

Preferably, the amount of PPC is 100 parts.

The dosage of the hydrophilic modifier is 1 to 3 parts, preferably 1 to 2 parts.

The using amount of the chain extender is 0.3-1.5 parts, preferably 0.5-1 part.

Preferably, the processing temperature of the twin-screw extruder is 140 ℃ to 160 ℃.

Preferably, the screw speed of the twin-screw extruder is 200-300 rpm.

Adding the prepared hydrophilic modified polypropylene carbonate particles into an injection molding machine, preparing a sample according to GB/T1040.1-2018, and carrying out contact angle test and thermal weight loss test.

Preferably, the injection molding machine temperature is 160 ℃ to 170 ℃.

Compared with the prior art, the invention has the following beneficial effects:

the principle of the invention is as follows: the PPC chain segment has terminal hydroxyl groups, thermal degradation is easy to occur in the processing process, the terminal hydroxyl groups are generated by random fracture thermal degradation or zipper release thermal degradation, and the thermal degradation of the PPC is further initiated by the existence of the terminal hydroxyl groups. And the hydrophilic modifier is added, so that the thermal degradation of the PPC is further aggravated, therefore, a chain extender capable of reacting with hydroxyl is added into the system, and the chain extender can be subjected to a grafting reaction with the PPC in the thermal degradation process of the PPC, so that on one hand, a polyhydroxy chain segment can be grafted on a PPC chain, the hydrophilicity of the PPC is improved, and on the other hand, the end hydroxyl of the PPC can be terminated, and the further thermal degradation is hindered.

Compared with the prior art, the invention has the following beneficial effects: the prepared hydrophilic modified polypropylene carbonate has good hydrophilicity and excellent thermal stability.

Drawings

FIG. 1 is a static contact angle plot of modified PPC prepared in example 1;

FIG. 2 is a static contact angle plot of modified PPC prepared in example 2;

FIG. 3 is a static contact angle plot of modified PPC prepared in example 3;

FIG. 4 is a static contact angle plot of modified PPC prepared in example 4;

FIG. 5 is a static contact angle plot of unmodified PPC prepared in comparative example 1;

Detailed Description

The examples of the present invention, in which the specific conditions are not specified, were conducted under the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. The raw materials used in the examples are all commercially available.

Example 1

100 parts of PPC, 1 part of Tween 20 and 0.3 part of diglycidyl terephthalate are uniformly mixed and then melted, blended and granulated by a double-screw extruder. The nine zones of the twin-screw extruder are respectively at 140 ℃ 140 ℃, 145 ℃ 150 ℃, 160 ℃ 160 ℃ 160 ℃. The twin-screw extruder was run at 200 rpm. Adding the granules into an injection molding machine, preparing samples according to the national standard GB/T1040.1-2018, and testing the parallel contact angle. The temperature of the injection molding machine is 160 ℃, 170 ℃ and 160 ℃. The specific results are shown in table 1 and fig. 1.

Example 2

100 parts of PPC, 2 parts of Tween 21 and 0.8 part of 2,2- (1, 3-phenylene) -bisoxazoline are uniformly mixed and then melted, blended and granulated by a double-screw extruder. The nine zones of the twin-screw extruder are respectively at 140 ℃ 140 ℃, 145 ℃ 150 ℃, 160 ℃ 160 ℃ 160 ℃. The twin-screw extruder was run at 200 rpm. Adding the granules into an injection molding machine, preparing samples according to the national standard GB/T1040.1-2018, and testing the parallel contact angle. The temperature of the injection molding machine is 160 ℃, 170 ℃ and 160 ℃. The specific results are shown in table 1 and fig. 2.

Example 3

100 parts of PPC, 3 parts of Tween 40 and 1.5 parts of diphenylmethane diisocyanate are uniformly mixed and then melted, blended and granulated by a double-screw extruder. The nine zones of the twin-screw extruder are respectively at 140 ℃ 140 ℃, 145 ℃ 150 ℃, 160 ℃ 160 ℃ 160 ℃. The twin-screw extruder was run at 200 rpm. Adding the granules into an injection molding machine, preparing samples according to the national standard GB/T1040.1-2018, and testing the parallel contact angle. The temperature of the injection molding machine is 160 ℃, 170 ℃ and 160 ℃. The specific results are shown in table 1 and fig. 3.

Example 4

100 parts of PPC, 3 parts of Tween 60 and 1.5 parts of diphenylmethane diisocyanate are uniformly mixed and then melted, blended and granulated by a double-screw extruder. The nine zones of the twin-screw extruder are respectively at 140 ℃ 140 ℃, 145 ℃ 150 ℃, 160 ℃ 160 ℃ 160 ℃. The twin-screw extruder was run at 200 rpm. Adding the granules into an injection molding machine, preparing samples according to the national standard GB/T1040.1-2018, and testing the parallel contact angle. The temperature of the injection molding machine is 160 ℃, 170 ℃ and 160 ℃. The specific results are shown in table 1 and fig. 4.

Comparative example 1

And melting, blending and granulating 100 parts of PPC by a double-screw extruder. The nine zones of the twin-screw extruder are respectively at 140 ℃ 140 ℃, 145 ℃ 150 ℃, 160 ℃ 160 ℃ 160 ℃. The twin-screw extruder was run at 200 rpm. Adding the granules into an injection molding machine, preparing samples according to the national standard GB/T1040.1-2018, and testing the parallel contact angle. The temperature of the injection molding machine is 160 ℃, 170 ℃ and 160 ℃. The specific results are shown in table 1 and fig. 5.

TABLE 1 contact angles of PPC in various examples and comparative examples

	Contact angle
		Example 1	65.2
Example 2	68.7
		Example 3	60.9
Example 4	61.1
		Comparative example 1	100.6

As can be seen from the data in Table 1 and FIGS. 1 to 5, comparative examples 1 to 4 and comparative example 1 show that the hydrophilicity of the hydrophilically modified polypropylene carbonate prepared by the present invention is significantly improved.

It is to be understood that the above examples are illustrative only for the purpose of clarity of description and are not limiting of the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious changes and modifications can be made without departing from the scope of the invention.