CN108164978B

CN108164978B - Degradable aliphatic polycarbonate/polyurethane copolymer film material and preparation thereof

Info

Publication number: CN108164978B
Application number: CN201711425426.1A
Authority: CN
Inventors: 陈乔健; 郭杨龙
Original assignee: Shanghai Deyi Chemical Co ltd
Current assignee: Shanghai Deyi Chemical Co ltd
Priority date: 2017-12-25
Filing date: 2017-12-25
Publication date: 2020-10-16
Anticipated expiration: 2037-12-25
Also published as: CN108164978A

Abstract

The invention relates to a degradable aliphatic polycarbonate/polyurethane copolymer film material and a preparation method thereof, wherein the copolymer film material is prepared by the following steps: (1): mixing 20-100 parts of hydroxyl-terminated aliphatic polycarbonate, 10-90 parts of polyurethane and 0.1-10 parts of chain extender, putting into a fluidized bed reactor, and carrying out prepolymerization reaction; (2): and (2) putting the prepolymer obtained in the step (1) into a screw extruder, adding 0-10 parts of a cross-linking agent, mixing, homogenizing, reacting, and extruding to form a film to obtain the target product. Compared with the prior art, the whole preparation method is divided into two-step polymerization, the copolymerization reaction is more sufficient, the physical properties of the copolymerization product such as toughness, temperature resistance and the like are more excellent, and compared with the traditional process, the method is more continuous and efficient, the temperature resistance of the copolymerization product is 30-80 ℃, the tensile strength is 30-120%, the batch is more uniform, and the batch melting point can be controlled within 2-3 ℃.

Description

Degradable aliphatic polycarbonate/polyurethane copolymer film material and preparation thereof

Technical Field

The invention relates to the field of degradable film materials, in particular to a degradable aliphatic polycarbonate/polyurethane copolymer film material and a preparation method thereof.

Background

High molecular polymers have been widely used in all fields related to human life from airplanes to clothes, but most of the polymers are derived from organic hydrocarbons, so that wastes of the polymers cannot be degraded for decades or even hundreds of years, and the polymers are directly prepared or foamed to prepare fast-consumable articles such as daily packaging materials, lunch boxes, consumables, electronic films, agricultural films and the like. The non-degradable lunch boxes and non-degradable plastic packaging bags produced in China each year can reach millions of tons, and the service life is less than twenty minutes on average. The environment and resources are under pressure which is difficult to measure, and the environment crisis is deeply recognized by governments, enterprises and the public in the whole society. At present, the development of degradable materials, the development of light materials and the development of substitute materials with higher physical properties become the most popular research and development fields.

Although the PU material has the advantages of high strength, high elasticity, high elongation, high wear resistance and the like, the general PU material has a biuret structure and an allophanate structure with poor heat resistance, so that the thermal stability is poor, the long-term use temperature is only 80 ℃, the application range of the PU material is greatly limited, the PPC belongs to thermoplastic biodegradable plastics, but the PPC material has insufficient tensile strength and cannot be directly used as a plate material and the like. At present, PPC and PU are blended and modified by a few people, but because the PPC and the PU have low reactivity, the PPC and the PU are difficult to copolymerize, and the PPC and PU copolymer with excellent temperature resistance and impact resistance is prepared. The invention provides an industrial application preparation method of a PPC/PU copolymer film based on the problem that PU and PPC are difficult to copolymerize.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a degradable aliphatic polycarbonate/polyurethane copolymer film material and a preparation method thereof, the whole preparation is divided into two steps of polymerization, the advantage of large residence time range of a fluidized bed reactor is utilized, the prepolymerization degree of PPC/PU in the fluidized bed reactor is adjusted, then the prepolymerization degree is deeply polymerized in a screw extruder, the copolymerization reaction is more sufficient, and the physical properties of the copolymer film material, such as tensile strength, temperature resistance and the like, are more excellent.

The purpose of the invention can be realized by the following technical scheme:

the invention aims to provide a degradable aliphatic polycarbonate/polyurethane copolymer film material which specifically comprises the following raw material components in parts by weight: 20-100 parts of hydroxyl-terminated aliphatic polycarbonate, 10-90 parts of polyurethane PU, 0.1-10 parts of chain extender and 0-10 parts of cross-linking agent.

Preferably, the chain extender is short-chain diol or amine. More preferably, the short-chain diol is 1, 4-butanediol, hexanediol or ethylene glycol.

Preferably, the hydroxyl-terminated aliphatic polycarbonate is polypropylene carbonate PPC, polybutylene carbonate PBC, polyethylene carbonate PEC, polybutylene carbonate PPMC, or polyhexamethylene carbonate PHC.

Preferably, the crosslinking agent is a compound containing 2 or more crosslinkable functional groups. More preferably, the crosslinking agent is an isocyanate such as a diisocyanate or a polyisocyanate, or a azapyridine. More preferably, the isocyanate may be one or more of toluene 2, 4 diisocyanate TDI, diphenylmethane diisocyanate MDI, isophorone diisocyanate IPDI, hexamethylene diisocyanate HDI, dicyclohexylmethane diisocyanate HMDI, HDI trimer, polymethylene polyphenyl polyisocyanate, and the like.

The invention also aims to provide a preparation method of the degradable aliphatic polycarbonate/polyurethane copolymer film material, which specifically comprises the following steps:

(1): mixing 20-100 parts of hydroxyl-terminated aliphatic polycarbonate, 10-90 parts of polyurethane and 0.1-10 parts of chain extender, putting into a fluidized bed reactor, and carrying out prepolymerization reaction;

(2): and (2) putting the prepolymer obtained in the step (1) into a screw extruder, adding 0-10 parts of a cross-linking agent, mixing, homogenizing, reacting, and extruding to form a film to obtain the target product.

Preferably, in step (1), the operating temperature in the fluidized bed reactor is controlled to be 70 to 210 ℃.

Preferably, in step (2), the operating temperature in the screw extruder is controlled to 170-210 ℃.

Preferably, in the step (2), the screw extruder is divided into a front section, a middle section and a rear section in the forward direction of the hot melt, wherein the crosslinking agent is added in the front section of the screw extruder.

The invention is different from the common degradable PPC/PU film material in the preparation process, firstly, the hydroxyl-terminated aliphatic polycarbonate such as PPC, PU and chain extender stay in a fluidized bed reactor for a long time to carry out partial prepolymerization chain extension reaction, then, the prepolymer copolymerized to a certain degree is discharged into a screw extruder, and further deep polymerization and crosslinking chain extension are carried out under the action of additives such as crosslinking agent and the like and the high-strength shearing and high-temperature action of a thread element in the screw extruder, so that a long straight chain polymer structure with multiple functional groups is obtained, and a melt product can have a wider film-forming operation time and temperature window, thereby obtaining the PPC type TPU film material.

Compared with the prior art, the invention has the following advantages:

(1) when the hydroxyl-terminated aliphatic polycarbonate/PU film material is prepared, a mode of combining a fluidized bed reactor and a screw extruder is adopted, the advantage of large residence time range of the fluidized bed reactor is utilized, parameters such as reaction time and temperature of the fluidized bed are adjusted according to the requirement of a reaction product, the prepolymerization degree of the hydroxyl-terminated aliphatic polycarbonate/PU in the fluidized bed reactor is adjusted, and then deep polymerization is carried out in the screw extruder.

(2) The introduction of the chain extender can introduce new groups into the molecular structure of the copolymer to repeat the sequence and repeat the molecular structure and the molecular chain segment of the material, so that the copolymer melt with proper melt strength and crystallization rate can be conveniently obtained, and the modified degradable copolymer with reasonable film-forming operation time and operation temperature window can realize the continuous controllable stable film-forming and physical property enhancement of the hydroxyl-terminated aliphatic polycarbonate/PU.

(3) Compared with other modes adopting single mode polymerization (such as only adopting a screw reactor), the physical properties of the hydroxyl-terminated aliphatic polycarbonate/PU copolymer film prepared by the invention, such as thermal stability, elongation at break, tensile strength and the like, are basically improved by more than 10-100%.

(4) Compared with the traditional process, the method is more continuous and efficient, the temperature resistance of the copolymerization product is 30-80 ℃, the tensile strength is 30-120%, the batches are more uniform, and the melting point difference of the batches can be controlled within 2-3 ℃.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

In addition, the starting materials used are all commercially available, unless otherwise specified.

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

"Polymer" means a polymeric compound prepared by polymerizing monomers of the same or different types. The generic term "polymer" embraces the terms "homopolymer", "copolymer", "terpolymer" and "interpolymer".

A degradable aliphatic polycarbonate/polyurethane copolymer film material comprises the following raw material components in parts by weight: 20-100 parts of hydroxyl-terminated aliphatic polycarbonate, 10-90 parts of polyurethane PU, 0.1-10 parts of chain extender and 0-10 parts of cross-linking agent.

As a preferred embodiment of the above scheme, the chain extender is short-chain diol or amine.

More preferably, the short-chain diol is 1, 4-butanediol, hexanediol or ethylene glycol.

In a preferred embodiment of the above aspect, the hydroxyl-terminated aliphatic polycarbonate is polypropylene carbonate PPC, polybutylene carbonate PBC, polyethylene carbonate PEC, polybutylene carbonate PPMC, or polyhexamethylene carbonate PHC.

As a preferred embodiment of the above scheme, the crosslinking agent is a compound containing 2 or more crosslinkable functional groups. More preferably, the crosslinking agent is an isocyanate such as a diisocyanate or a polyisocyanate, or a azapyridine. More preferably, the isocyanate may be one or more of toluene 2, 4 diisocyanate TDI, diphenylmethane diisocyanate MDI, isophorone diisocyanate IPDI, hexamethylene diisocyanate HDI, dicyclohexylmethane diisocyanate HMDI, HDI trimer, polymethylene polyphenyl polyisocyanate, and the like.

A preparation method of a degradable aliphatic polycarbonate/polyurethane copolymer film material comprises the following steps:

As a preferred embodiment of the above, in the step (1), the operating temperature in the fluidized-bed reactor is controlled to 70 to 210 ℃.

As a preferred embodiment of the above, in the step (2), the operating temperature in the screw extruder is controlled to 170-210 ℃.

As a preferred embodiment of the above, in the step (2), the screw extruder is divided into a front stage, a middle stage and a rear stage in the forward direction of the hot melt, wherein the crosslinking agent is added in the front stage of the screw extruder.

The invention is described in detail below with reference to the figures and specific embodiments.

In the following examples, unless otherwise specified, all reagents and methods commonly used in the art are used.

Example 1

A preparation method of a degradable PPC/PU copolymer film material is shown in figure 1, and comprises the following steps:

(1): mixing 80 parts of PPC, 60 parts of polyurethane and 5 parts of chain extender (1, 4-butanediol is adopted in the embodiment), putting into a fluidized bed reactor, and carrying out prepolymerization reaction for 50min at 100 ℃;

(2): and (2) putting the prepolymer obtained in the step (1) into a screw extruder, mixing, homogenizing and reacting at 190 ℃, and finally extruding, casting and forming a film.

Comparative example 1

Compared with example 1, except that the fluidized bed reactor is omitted, all the raw materials are uniformly put into the screw extruder to be reacted, and the rest is the same.

Example 2

The same is true as in example 1, except that 5 parts of the crosslinker HDI trimer are also added.

Example 3

The same applies to example 1, except that 10 parts of rubber (in this example, a rubber terminated with hydroxyl groups at both ends) was added in step (2).

The physical properties such as elongation at break and tensile strength of examples 1 to 3 and comparative example 1 were measured, and the obtained data are shown in table 1 below.

TABLE 1

As can be seen from the data in Table 1, the tensile strength of the film formed by the pre-polymerization in the fluidized bed reactor is improved by more than 20%, even up to 120% or more, compared with that of the film formed by the non-pre-polymerization in the fluidized bed, and the physical property enhancement is very obvious.

In addition, when the copolymer film obtained by the modified process of example 1 and the conventional process of comparative example 1 were subjected to a performance test, it was found that the conventional process started to be tacky at substantially 120 ℃ or so, while the tacky temperature of the copolymer film obtained in example 1 was increased to 210 ℃ or so, and it was seen that the improvement in temperature resistance was also very significant.

Meanwhile, when multiple batches of secondary production are carried out according to the processes of the example 1 and the comparative example 1, the melting point of each batch of the film of the example 1 can be controlled within 2-3 ℃, the uniformity among batches is better, and the melting point difference of each batch of the film of the comparative example 1 is even up to more than 10 ℃, and the stability is poorer.

Example 4

Different from the example 1, the addition amount of each raw material component in the example is changed as follows: 20 parts of PPC, 10 parts of PU, 0.1 part of chain extender and 1 part of cross-linking agent.

Example 5

Different from the example 1, the addition amount of each raw material component in the example is changed as follows: 100 parts of PPC, 90 parts of PU, 10 parts of a chain extender and 10 parts of a cross-linking agent.

Example 6

Different from the example 1, the addition amount of each raw material component in the example is changed as follows: 60 parts of PPC, 40 parts of PU, 3 parts of a chain extender and 5 parts of a cross-linking agent.

Example 7

The same is true as in example 2, except that the crosslinker in this example is replaced with 5 parts of azapyridine.

Examples 8 to 14

Compared with example 2, the crosslinking agent HDI trimer is mostly the same except that in this example, azapyridine, toluene 2, 4 diisocyanate TDI, diphenylmethane diisocyanate MDI, isophorone diisocyanate IPDI, hexamethylene diisocyanate HDI, dicyclohexylmethane diisocyanate HMDI, and polymethylene polyphenyl polyisocyanate are respectively replaced.

Examples 15 to 17

The same is true as in example 1, except that the chain extender is replaced with ethylene glycol, hexylene glycol and amine, respectively, in this example.

In addition, when comparing the film material obtained in each of the above embodiments with the comparative example without adding the chain extender, it is found that the film forming operation time and the temperature window of the obtained polymer melt are relatively increased after adding the chain extender, which is more convenient for the film forming operation, while the comparative example without adding the chain extender has too narrow relative operation time and temperature window, and the yield of the melt film forming is lower.

Example 18

Compared with the example 1, the method is mostly the same, except that in the step (1) of the example, the operation temperature in the fluidized bed reactor is controlled to be 70 ℃, and the operation time is 6 hours;

in step (2), the operating temperature in the screw extruder was controlled to 170 ℃.

Example 19

Compared with the example 1, most of the method is the same, except that in the step (1) of the example, the operation temperature in the fluidized bed reactor is controlled to be 210 ℃, and the operation time is 30 min;

in step (2), the operating temperature in the screw extruder was controlled to 210 ℃.

Example 20

Compared with the example 1, the method is mostly the same, except that in the step (1) of the example, the operation temperature in the fluidized bed reactor is controlled to be 150 ℃, and the operation time is 4 h;

in the step (2), the operating temperature in the screw extruder was controlled to 180 ℃.

Examples 21 to 24

Unlike example 1, in this example, the aliphatic polycarbonate was replaced with polybutylene carbonate PBC, polyethylene carbonate PEC, polybutylene carbonate PPMC, and polyhexamethylene carbonate PHC, respectively.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. The preparation method of the degradable aliphatic polycarbonate/polyurethane copolymer film material is characterized in that the copolymer film material comprises the following raw material components in parts by weight: 20-100 parts of hydroxyl-terminated aliphatic polycarbonate, 10-90 parts of Polyurethane (PU), 0.1-10 parts of chain extender and 0-10 parts of cross-linking agent;

the chain extender is selected from 1, 4-butanediol, hexanediol or ethylene glycol;

the hydroxyl-terminated aliphatic polycarbonate is polypropylene carbonate PPC, polybutylene carbonate PBC, polyethylene carbonate PEC, polyethylene glycol carbonate PPMC or polyhexamethylene carbonate PHC;

the preparation method comprises the following steps:

2. The method for preparing a degradable aliphatic polycarbonate/polyurethane copolymer film material of claim 1, wherein the crosslinking agent is a compound containing 2 or more crosslinkable functional groups.

3. The method for preparing the degradable aliphatic polycarbonate/polyurethane copolymer film material as claimed in claim 2, wherein the cross-linking agent is isocyanate or pyridine nitride.

4. The method for preparing a degradable aliphatic polycarbonate/polyurethane copolymer film material according to claim 1, wherein in the step (1), the operating temperature in the fluidized bed reactor is controlled to be 70-210 ℃.

5. The method for preparing a degradable aliphatic polycarbonate/polyurethane copolymer film material as claimed in claim 1, wherein the operation temperature in the screw extruder in step (2) is controlled to 170-210 ℃.

6. The method for preparing a degradable aliphatic polycarbonate/polyurethane copolymer film material of claim 1, wherein in the step (2), the crosslinking agent is added in a front section of a screw extruder.