WO2018058816A1

WO2018058816A1 - Method for manufacturing polyoxazoline chain extending agent

Info

Publication number: WO2018058816A1
Application number: PCT/CN2016/111432
Authority: WO
Inventors: 郑玉婴; 李雅泊
Original assignee: 福州大学
Priority date: 2016-09-29
Filing date: 2016-12-22
Publication date: 2018-04-05
Also published as: CN106432568A; CN106432568B

Abstract

The present invention discloses a method for manufacturing a polyoxazoline chain extending agent. The method comprises: using 2-p-hydroxyphenyl-2-oxazoline to perform, under specific conditions, an esterification reaction with a propenoyl chloride so as to produce a propenoic acid monomer comprising an oxazoline group; and inducing carbon-carbon double bond polymerization under specific conditions to produce a macromolecule comprising multiple oxazoline groups. The manufacturing method provided by the present invention can be performed easily, has high yield, and produces a polyoxazoline chain extending agent with high purity and environmental friendliness. The invention has a wide range of prospective applications in the field of chain extension processing for materials such as polyurethanes, polyesters, nylons, and the like.

Description

Preparation method of polyoxazoline-based chain extender

Technical field

The invention belongs to the field of preparation of oxazoline-based chain extenders, in particular to a preparation method of polyoxazoline-based chain extenders.

Background technique

In the current mainstream of green and low-carbon economy development, how to improve the utilization rate of materials has always been the focus of everyone's attention. Plastic products have their unique properties. In the process of use, the molecular weight is often reduced due to the breakage of intramolecular chemical bonds, which affects their performance. The molecular weight reduction in plastic recycled materials is more obvious. A chain extender, also known as a chain extender, is usually a polyfunctional compound which is a substance which reacts with a functional group on a linear polymer chain to expand a molecular chain and increase its molecular weight. The chain extender can increase the relative molecular mass of the polymer in a short time and accelerate the reaction process. It is often used to improve the mechanical properties and process properties of polyurethane, polyester, nylon and other products, especially in the processing of plastic recycled materials.

In the polyurethane, polyester, and nylon processing processes, the molecular mass is lowered due to thermal degradation and hydrolysis, and the number of terminal carboxyl groups is increased, so that the mechanical and chemical properties of the polymer are lowered. A bifunctional small molecule compound is added under reactive blending conditions. For example: difunctional acid derivatives, isocyanates, acid anhydrides, oxazolines, and epoxides, etc. These difunctional compounds contain a functional group that easily reacts with a carboxyl group, a hydroxyl group, an amino group, etc., and can directly react with a low molecular mass oligomer. The formation of "bridge" between the two polymer chains significantly increases the molecular mass, increases the viscosity of the system, and lowers the terminal carboxyl group content.

The macromolecular compatibilizing chain extender is a long-chain compatibilizing chain extender compared with a conventional difunctional isocyanate, anhydride, oxazoline and other small molecule compounds, and has a plurality of more dispersed reactivity in the molecular chain. The oxazoline functional group connects the molecular chains of the polyester and other materials, and is in a branched state as a whole, and does not cause problems such as gelation and low chain expansion efficiency. Looking at the status quo at home and abroad, the focus of research and development of macromolecular chain extenders has been concentrated on epoxy functional polymers, but the preparation methods of such chain extenders are costly, complicated in synthesis, and low in yield. Only a few products have been applied in the market. Chain extenders containing other groups are rarely of interest.

Therefore, a method of preparing a novel chain extender which is an acrylic polymer having a plurality of oxazoline groups is proposed herein. Finally, the chain extender with excellent chain extension performance can be widely used in the processing of polyurethane, polyester, nylon and other products.

Summary of the invention

The object of the present invention is to provide a method for preparing a polyoxazoline-based chain extender, in view of the problems of high cost, complicated synthesis method and low yield of the chain extender prepared in the prior art. The preparation method has the advantages of low cost, simple operation and high yield, and the obtained chain extender has obvious toughening and viscosity-increasing effect, and the mechanical properties of the material after chain extension are good.

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for preparing a polyoxazoline-based chain extender, which comprises esterification of 2-p-hydroxyphenyl-2-oxazoline with acryloyl chloride at 0-10 ° C using thionyl chloride as solvent An oxazoline group-containing acrylic monomer; then the carbon-carbon double bond polymerization of the monomer is initiated with ammonium persulfate at 50-70 ° C to form a macromolecular chain extender containing a plurality of oxazoline groups.

The specific preparation method is as follows:

1) Synthesis of oxazoline monomers containing carbon-carbon double bonds: 2-p-hydroxyphenyl-2-oxazoline:

Mixing with acryloyl chloride molar ratio 1:2-8, reacting at 0-10 °C for 2-8h, and evaporating the solvent to obtain the oxazoline monomer containing carbon-carbon double bond:

2) Synthesis of polyoxazoline-based chain extender: The oxazoline monomer containing carbon-carbon double bond is dissolved in thionyl chloride, and ammonium persulfate is used as an initiator to condense and reflux at 50-70 ° C. After 2-12 h, the precipitate in the reaction system was dissolved in tetrahydrofuran, and then the solution was precipitated with petroleum ether or methanol solution, filtered, and the filtrate was evaporated to dryness at 70 ° C to obtain a polyoxazoline-based chain extender.

The method for synthesizing 2-p-hydroxyphenyl-2-oxazoline described in the step 1) is: dissolving 100 g of methylparaben and 120 g of ethanolamine in methanol, and reacting at 140 ° C for 4-6 h to obtain After recrystallization from N-hydroxyethyl-p-hydroxybenzamide and ethanol, the mixture was stirred under reflux with 108 mL of dichloromethane and 200 mL of dichloromethane at room temperature for 24 hours, filtered under reduced pressure, and the obtained solid was placed in 300 mL of ice water and stirred slowly. Add sodium bicarbonate until no bubbles, then add sodium bicarbonate to adjust the pH to 8-9, and filter under reduced pressure to obtain 2-p-hydroxyphenyl-2-oxazoline

The solvent used in the monomer synthesis in step 1) is thionyl sulfoxide.

In the reaction system of the step 2), the molar fraction of ammonium persulfate is 0.2% to 1%.

In the methanol solution described in the step 2), the volume ratio of methanol to water is 3:1.

A polyoxazoline-based chain extender obtained by the production method according to any one of the preceding claims, which has a degree of polymerization of from 20 to 250.

A specific synthetic route diagram of the monomer of the present invention is shown in FIG.

10-50g of the obtained chain extender is melt-blended with 1000-2000g of R-PET, granulated and dried, and then tested for basic properties, and the chain extension effect of the chain extender is evaluated.

The beneficial effects of the invention are:

The preparation method of the invention is simple and convenient, and has high yield, and provides a new method for synthesizing the chain extender; the obtained chain extender has stable chemical property, excellent chain extension effect and environmental friendliness, and is in polyurethane, polyester and nylon. It has a wide application prospect in product processing.

DRAWINGS

1 is a synthetic route diagram of an oxazoline monomer having a carbon-carbon double bond of the present invention;

Figure 2 is a ¹ H NMR spectrum of 2-p-hydroxyphenyl-2-oxazoline;

Figure 3 is a ¹³ C NMR spectrum of 2-p-hydroxyphenyl-2-oxazoline;

Figure 4 is a ¹ H NMR spectrum of a chain extender;

Figure 5 is a ¹³ C NMR spectrum of the chain extender.

detailed description

The invention is further illustrated by the following examples, but the scope of the invention is not limited to the following examples. Example 1

A preparation method of a polyoxazoline-based chain extender, the specific steps are as follows:

1) Synthesis of 2-p-hydroxyphenyl-2-oxazoline: 100 g of methylparaben and 120 g of ethanolamine were dissolved in a methanol solvent, placed in an atmospheric distillation apparatus at 140 ° C for 5 h, and then decompressed. Distilling off methanol and excess ethanolamine to give a pale yellow solid N-hydroxyethyl p-hydroxybenzamide; N-hydroxyethyl p-hydroxybenzamide was recrystallized from ethanol with 108 mL of thionyl chloride, 200 mL of dichloromethane at room temperature The reaction was stirred under reflux for 24 h, filtered under reduced pressure, and the obtained solid was placed in 300 mL of ice water, stirred, and sodium bicarbonate was slowly added until no bubbles were obtained, and then the pH was adjusted to 8 by adding sodium hydrogencarbonate, and dried under reduced pressure to give a white solid. Product, yield 92%;

2) Preparation of oxazoline monomer containing carbon-carbon double bond: 100 g of 2-p-hydroxyphenyl-2-oxazoline was added to a 1000 mL four-necked flask, and 500 mL of thionyl chloride was added thereto with stirring until completely dissolved. Then, a solution of acryloyl chloride containing 1% by weight of a polymerization inhibitor is added dropwise, and the molar ratio of 2-p-hydroxyphenyl-2-oxazoline to acryloyl chloride is 1:4; the reaction is carried out at 5 ° C for 4 hours to prepare carbon-carbon double The oxazoline monomer of the bond is dried at 70 ° C, and the solvent is distilled off, and the yield is 51.3%;

3) Polymerization reaction: 100 g of the above-obtained oxazoline monomer containing a carbon-carbon double bond is dissolved in thionyl chloride as a solvent, and then added to a three-necked flask, and slowly added dropwise to a molar fraction of 1%. Ammonium sulphate solution; condensed and refluxed at 50 ° C for 6 h, the solution was transferred to a beaker, the precipitate was dissolved in THF, and the solution was precipitated with petroleum ether to remove unreacted monomers, filtered, and the filtrate was evaporated to dryness at 70 ° C. The solvent obtained a polymer containing a plurality of oxazoline groups, and the degree of polymerization was 73.

20 g of the obtained chain extender was melt-blended with 1980 g of R-PET, granulated and dried, and the basic properties were tested by injection molding, and the chain extension effect of the chain extender was evaluated.

Example 2

2) Preparation of oxazoline monomer containing carbon-carbon double bond: 100 g of 2-p-hydroxyphenyl-2-oxazoline was added to a 1000 mL four-necked flask, and 500 mL of thionyl chloride was added thereto with stirring until completely dissolved. Then, a solution of acryloyl chloride containing 1 wt% of a polymerization inhibitor is added dropwise, and the molar ratio of 2-p-hydroxyphenyl-2-oxazoline to acryloyl chloride is 1:4; the reaction is carried out at 5 ° C for 8 h to prepare carbon-carbon double The oxazoline monomer of the bond is dried at 70 ° C, and the solvent is distilled off, and the yield is 62.7%;

3) Polymerization reaction: 100 g of the above-obtained oxazoline monomer containing a carbon-carbon double bond is dissolved in thionyl chloride as a solvent, and then added to a three-necked flask, and slowly added dropwise to a molar fraction of 1%. Ammonium sulphate solution; condensed and refluxed at 55 ° C for 12 h, the solution was transferred to a beaker, the precipitate was dissolved in THF, and the solution was precipitated with petroleum ether to remove unreacted monomers, filtered, and the filtrate was evaporated to dryness at 70 ° C. The solvent obtained a polymer containing a plurality of oxazoline groups, and the degree of polymerization was 197.

Example 3

1) Synthesis of 2-p-hydroxyphenyl-2-oxazoline: 100 g of methylparaben and 120 g of ethanolamine were dissolved in a methanol solvent, placed in an atmospheric distillation apparatus at 140 ° C for 5 h, and then decompressed. Distillation of methanol and excess ethanol The amine is obtained as a pale yellow solid N-hydroxyethyl p-hydroxybenzamide; the N-hydroxyethyl p-hydroxybenzamide is recrystallized from ethanol, and then reacted with 108 mL of thionyl chloride and 200 mL of dichloromethane at room temperature for 24 h. The mixture was filtered under pressure, and the obtained solid was placed in 300 mL of ice water, stirred, and sodium bicarbonate was added continuously until no air bubbles were added thereto, and the pH was adjusted to 8 by adding sodium hydrogencarbonate, and the product was obtained by filtration under reduced pressure to give a white solid. %;

2) Preparation of oxazoline monomer containing carbon-carbon double bond: 100 g of 2-p-hydroxyphenyl-2-oxazoline was added to a 1000 mL four-necked flask, and 500 mL of thionyl chloride was added thereto with stirring until completely dissolved. Then, a solution of acryloyl chloride containing 1 wt% of a polymerization inhibitor was added dropwise, and the molar ratio of 2-p-hydroxyphenyl-2-oxazoline to acryloyl chloride was 1:8; the reaction was carried out at 5 ° C for 4 h to prepare carbon-carbon double The oxazoline monomer of the bond is dried at 70 ° C, and the solvent is distilled off, and the yield is 84.1%;

3) Polymerization reaction: 100 g of the above-obtained oxazoline monomer containing a carbon-carbon double bond is dissolved in thionyl chloride as a solvent, and then added to a three-necked flask, and slowly added dropwise to a molar fraction of 1%. Ammonium sulphate solution; condensed and refluxed at 60 ° C for 10 h, the solution was transferred to a beaker, the precipitate was dissolved in THF, and the solution was precipitated with petroleum ether to remove unreacted monomers, filtered, and the filtrate was evaporated to dryness at 70 ° C. The solvent obtained a polymer containing a plurality of oxazoline groups, and the degree of polymerization was 217.

Example 4

2) Preparation of oxazoline monomer containing carbon-carbon double bond: 100 g of 2-p-hydroxyphenyl-2-oxazoline was added to a 1000 mL four-necked flask, and 500 mL of thionyl chloride was added thereto with stirring until completely dissolved. Then, a solution of acryloyl chloride containing 1 wt% of a polymerization inhibitor was added dropwise, and the molar ratio of 2-p-hydroxyphenyl-2-oxazoline to acryloyl chloride was 1:8; and the reaction was carried out at 5 ° C for 8 h to prepare carbon-carbon double The oxazoline monomer of the bond is dried at 70 ° C, and the solvent is distilled off, and the yield is 73.6%;

3) Polymerization reaction: 100 g of the above-obtained oxazoline monomer containing a carbon-carbon double bond is dissolved in thionyl chloride as a solvent, and then added to a three-necked flask, and slowly added dropwise to a molar fraction of 1%. Ammonium sulphate solution; condensed and refluxed at 65 ° C for 8 h, the solution was transferred to a beaker, the precipitate was dissolved in THF, and the solution was precipitated with petroleum ether to remove The reaction monomer was filtered, and the filtrate was evaporated to dryness at 70 ° C to obtain a polymer containing a plurality of oxazoline groups, and the degree of polymerization was 131.

Comparative example 1

1,3-bis(2-oxazolyl)benzene (MPBO) was selected as a chain extender for comparative test. 20g of this chain extender was melt-blended with 1980g R-PET, granulated and dried, and then injection molded to test its Basic performance, comparative evaluation of the chain extension effect of the chain extender prepared by this patent.

Comparative example 2

ADR-4380S was used as a chain extender for comparative testing. ADR-4380S is a macromolecular chain extender containing multiple epoxy groups and is a chain extender produced by BASF. 20g of the chain extender was melt-blended with 1980g R-PET, granulated and dried, and then tested for basic properties. The chain extension effect of the chain extender prepared in this patent was compared and evaluated.

The experimental comparison shows that the chain extender has excellent effect on R-PET chain extension. After adding the chain extender, the viscosity and impact strength of R-PET are greatly improved, and the chain extension effect on R-PET is better than 1,3-. Bis(2-oxazolinyl)benzene (MPBO) is equivalent to BASF's ADR-4380S chain extension.

Claims

A method for preparing a polyoxazoline-based chain extender, comprising: the following steps:

1) Synthesis of oxazoline monomers containing carbon-carbon double bonds: 2-p-hydroxyphenyl-2-oxazoline:
Mixing with acryloyl chloride molar ratio 1:2-8, reacting at 0-10 °C for 2-8h, and evaporating the solvent to obtain the oxazoline monomer containing carbon-carbon double bond:

2) Synthesis of polyoxazoline-based chain extender: The oxazoline monomer containing carbon-carbon double bond is dissolved in thionyl chloride, and ammonium persulfate is used as an initiator to condense and reflux at 50-70 ° C. After 2-12 h, the precipitate in the reaction system was dissolved in tetrahydrofuran, and then the solution was precipitated with petroleum ether or methanol solution, filtered, and the filtrate was evaporated to dryness at 70 ° C to obtain a polyoxazoline-based chain extender.
The method for preparing a polyoxazoline-based chain extender according to claim 1, wherein the 2-p-hydroxyphenyl-2-oxazoline described in the step 1) is synthesized by: 100 g of a pair Methyl hydroxybenzoate and 120 g of ethanolamine are dissolved in methanol and reacted at 140 ° C for 4-6 h to obtain N-hydroxyethyl p-hydroxybenzamide. After recrystallization from ethanol, it is combined with 108 mL of thionyl chloride and 200 mL of dichloromethane. The reaction was stirred under reflux at room temperature for 24 h, and filtered under reduced pressure. The obtained solid was placed in 300 mL of ice water, stirred, and sodium bicarbonate was slowly added until no bubbles were obtained, and the pH was adjusted to 8-9 by adding sodium hydrogencarbonate, and dried under reduced pressure. 2-Phenylphenyl-2-oxazoline is obtained.
The method for preparing a polyoxazoline-based chain extender according to claim 1, wherein the solvent used in the synthesis of the monomer in the step 1) is thionyl chloride.
The method for producing a polyoxazoline-based chain extender according to claim 1, wherein in the reaction system of the step 2), the molar fraction of ammonium persulfate is from 0.2% to 1%.
The method for preparing a polyoxazoline-based chain extender according to claim 1, wherein the methanol solution in the step 2) has a volume ratio of methanol to water of 3:1.
A polyoxazoline-based chain extender obtained by the production method according to any one of claims 1 to 5, which has a degree of polymerization of from 20 to 250.