KR100871827B1 - Polyolefine nano-composite and method for manufacturing the same - Google Patents

Abstract

A nanocomposite, and a method for preparing the nanocomposite are provided to improve the compatibility of a polyolefin-based resin and a POSS molecule, to enhance heat resistance and modulus and to prevent the coagulation of POSS molecule in a polymer resin. A nanocomposite comprises 100 parts by weight of a polyolefin-based resin; 1-10 parts by weight of a POSS molecule which is dispersed in the polyolefin-based resin; and 0.1-1 parts by weight of a modified polyolefin-based resin as a compatibilizer which is prepared by graft polymerizing a polyolefin-based resin and a silane compound. Preferably the polyolefin-based resin is selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin.

Description

Polyolefin Nanocomposite and Method for Manufacturing the Same {Polyolefine Nano-Composite And Method for Manufacturing The Same}

The present invention relates to a polymer nanocomposite, and more particularly, to a polyolefin-based nanocomposite including POSS molecules having excellent heat resistance and modulus so as to be applied to automobile interior materials and parts.

Polymer nanocomposites are complexes in which polymers, inorganic materials or metal particles of 1 to 100 nanometers in size are dispersed in a polymer resin, and have strength, stiffness, barrier properties against gas or liquid, without impairing the impact resistance, toughness and transparency of the polymer. Wear resistance and high temperature stability have been greatly improved, and thus it is expected to be applied to fields such as automobile, electronic information, and civil engineering.

Since the polymer nanocomposite is used by peeling or dispersing the reinforcing material up to the nanosite, it exhibits better physical properties even when using a smaller amount of inorganic filler than the conventional inorganic filler reinforcing composite material, and is very advantageous in terms of cost and performance.

However, since the nanocomposite is a composite material manufactured by combining heterogeneous materials, there is a problem in that phase separation due to heterogeneous components occurs and easily reaches the limit physical properties. Therefore, in order to form a stable composite system, it is very important to increase the affinity of two phases to extremely lower the interfacial tension between the phases and to stabilize the system so as not to aggregate or separate.

Conventionally, development of nanocomposites has been made mainly of high polar polymer resins such as nylon, polyester, and epoxy, and one of them is nylon. On the other hand, nonpolar polymer resins, such as polypropylene or polyethylene, have problems in the process of agglomeration during the production of nanocomposites. Therefore, in order to improve the physical properties of polymer nanocomposites using nonpolar resins such as polyolefin resins, development of compatibility improvement and dispersion state optimization techniques is necessary.

In order to solve the above problems, the present invention is to provide a polyolefin nanocomposite having excellent physical properties such as heat resistance and modulus because the POSS molecules are not aggregated in the polymer resin by improving the compatibility between the POSS molecules and the polyolefin resin.

In order to achieve the above object, the present invention provides a polyolefin resin comprising a polyolefin resin, a POSS molecule dispersed in the polyolefin resin and a modified polyolefin resin prepared by graft polymerization of a polyolefin resin and a silane compound as a compatibilizer. Provided are nanocomposites.

It is preferable to use a polyolefin resin selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin.

The content of the modified polyolefin resin is preferably 0.1 parts by weight to 1 part by weight based on 100 parts by weight of the polyolefin resin.

The modified polyolefin resin is preferably formed by graft polymerization of 100 parts by weight of polyolefin resin and 1 to 10 parts by weight of a silane compound.

The polyolefin resin used in the production of the modified polyolefin resin is preferably selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin.

It is preferable to use what is represented by following formula (1) as the said silane compound.

[Formula 1]

In Formula 1, R ₁ is an alkyl group having 1 to 10 carbon atoms or an alkoxy group, halogen group or aryl group having 1 to 10 carbon atoms. R <_2> is a C1-C10 functional group containing a vinyl group or an acryl group at the terminal group.

It is preferable to use the POSS molecule | numerator represented by following formula (2).

[Formula 2]

In Formula 2, R ₃ is an alkyl group having 1 to 10 carbon atoms, an alkene group, an aryl group, an alkoxy group, a cycloalkane group or a halogen group, and R ₄ is a functional group of an oxide having 1 to 10 carbon atoms, hydroxyl group or glycidyl group to be.

The content of the POSS molecule is preferably 1 to 10 parts by weight based on 100 parts by weight of the polyolefin resin.

In addition, the polyolefin-based nanocomposite of the present invention graft polymerized polyolefin-based resins and silane compounds to produce modified polyolefin-based resins (S1), and add and mix the modified-type polyolefin-based resins to the polyolefin-based resins (S2). ), Can be prepared by adding and mixing the POSS molecules to the product produced through the step (S2).

The polyolefin resin used in the step (S1) is preferably used selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin.

The polyolefin resin used in the step (S2) is preferably used selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin.

The content of the silane compound used in the step (S1) is preferably 1 part by weight to 10 parts by weight relative to 100 parts by weight of the polyolefin resin used in the step (S1).

It is preferable to use what is represented by following formula (1) as the said silane compound.

[Formula 1]

In Formula 1, R ₁ is an alkoxy group, a halogen group, or an aryl group or an alkyl group having 1 to 10 carbon atoms having 1 to 10 carbon atoms. R <_2> is a C1-C10 functional group containing a vinyl group or an acryl group at the terminal group.

The step (S1) may be performed using an initiator within the range of 0.1 to 1 parts by weight relative to 100 parts by weight of the polyolefin resin. The initiator may be selected from one or more of benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumyl hydroperoxide, hydrogen peroxide potassium persulfate and dicumyl peroxide.

The step (S2) is preferably made by melt mixing the modified polyolefin-based resin and the polyolefin-based resin produced in the (S1) step.

The content of the modified polyolefin resin used in the step (S2) is preferably used 0.1 parts to 1 parts by weight based on 100 parts by weight of the polyolefin resin used in the step (S2).

The step (S3) is preferably made by melting and mixing the product and the POSS molecules in the step (S2).

The content of the POSS molecules used in the step (S3) is preferably used 1 to 10 parts by weight relative to 100 parts by weight of the polyolefin resin used in the step (S2).

It is preferable to use the POSS molecule | numerator represented by following formula (2).

[Formula 2]

In Formula 2, R ₃ is an alkyl group having 1 to 10 carbon atoms, an alkene group, an aryl group, an alkoxy group, a cycloalkane group or a halogen group, and R ₄ is a functional group of an oxide having 1 to 10 carbon atoms, a hydroxyl group or a glycidyl group. .

Hereinafter, the present invention will be described in more detail.

The polyolefin-based nanocomposites of the present invention include polyolefin-based resins, modified polyolefin-based resins, and POSS molecules.

The polyolefin resin is preferably selected from the group consisting of polyethylene resins, polypropylene resins, polyacetylene resins, and polyisobutylene resins. However, it is not limited thereto.

Since the polyolefin resin is a non-polar resin, unlike nylon, polyester, and the like, which is a polar resin, the dispersibility of the POSS molecules is poor when the nanocomposite is manufactured, which causes problems such as failure to effectively disperse in the polyolefin resin and aggregation. Therefore, the present invention solves the problem of aggregation due to poor dispersibility when the POSS molecules are introduced by using a modified polyolefin resin obtained by graft polymerization of a polyolefin resin and a silane compound as a compatibilizer in the preparation of the nanocomposite.

In general, a pre-made block copolymer or a free graft copolymer may be used or an in-situ reaction may be performed depending on a method of introducing a compatibilizer during the mixing process of the polymer blend. And a type compatibilizer. The nanocomposite of the present invention is prepared as a compatibilizer using a modified polyolefin-based resin prepared by graft polymerization of a polyolefin-based resin as a silane compound as a compatibilized graft copolymer.

The content of the modified polyolefin resin used as the compatibilizer is preferably 0.1 part by weight to 1 part by weight, and more preferably 0.1 part by weight to 0.5 part by weight based on 100 parts by weight of the polyolefin resin. When the content of the modified polyolefin-based resin is less than 0.1 parts by weight, the role as a compatibilizer is insignificant, and when the content of more than 1 part by weight, agglomeration of particles occurs rather than a disadvantage in that the dispersibility is lowered.

The polyolefin resin used to prepare the modified polyolefin resin is preferably selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin. However, it is not limited thereto.

As the silane compound used to prepare the modified polyolefin resin, it is preferable to use one represented by Chemical Formula 1. Representative examples of such silane compounds include vinyltrimethoxysilane, vinyltrimethylsilane, vinyltriphenylsilane, vinyltriethoxysilane, vinyltriethylsilane, acryltrimethoxysilane, and acryltriethoxysilane. Vinyltrimethoxysilane and vinyltriethoxysilane.

[Formula 1]

In Formula 1, R ₁ is an alkoxy group, a halogen group, or an aryl group or an alkyl group having 1 to 10 carbon atoms having 1 to 10 carbon atoms. R <_2> is a C1-C10 functional group containing a vinyl group or an acryl group at the terminal group.

The content of the silane compound is preferably 1 part by weight to 10 parts by weight, and more preferably 5 parts by weight to 10 parts by weight, based on 100 parts by weight of the polyolefin resin. When the silane compound is less than 1 part by weight, the dispersibility is not improved. When the silane compound is more than 10 parts by weight, the content of the silane compound is increased, so that the dispersibility is lowered, which results in a disadvantage in that the physical properties are deteriorated.

The POSS molecules are introduced into polyolefin resins and used to increase thermal stability, wear resistance and mechanical strength. POSS molecules have excellent thermal stability and particle size of 100 nm or less, and have organic and inorganic functional groups, which may have various reactivity. POSS molecule if a nanostructure of a set having the empirical formula RSiO _{1 .5} are functional groups connected to the somatic Si-O backbone. Generally R is a linear aliphatic or aromatic group which may further contain hydrogen, siloxy or cyclic groups, or reactive functional groups.

It is preferable to use the POSS molecule | numerator represented by following formula (2). Such POSS molecules include glycidylcyclohexyl-POSS, glycidylcyclopentyl-POSS, glycidylethyl-POSS, glycidylisobutyl-POSS, glycidylisooctyl-POSS, glycidylphenyl- POSS is typical. However, it is not limited to this. Formula 3 below shows glycidylisobutyl-POSS.

[Formula 2]

In Formula 2, R ₃ is an alkyl group having 1 to 10 carbon atoms, an alkene group, an aryl group, an alkoxy group, a cycloalkaine group or a halogen, and R ₄ is a functional group of an oxide having 1 to 10 carbon atoms, hydroxyl group or glycidyl group.

[Formula 3]

The content of the POSS molecule is preferably 1 to 10 parts by weight, more preferably 1 to 5 parts by weight based on 100 parts by weight of the polyolefin resin. If the content of the POSS molecule is less than 1 part by weight, the content of the POSS molecule is small, so that the effect of improving heat resistance and modulus is insignificant.If the content of the POSS molecule is more than 10 parts by weight, the content of the POSS is increased so that the dispersibility is lowered and the mechanical strength is increased. Disadvantages such as deterioration occur.

The polyolefin-based nanocomposites can be typically produced by the following method.

First, a modified polyolefin resin is prepared by graft polymerization of a polyolefin resin and a silane compound (S1).

As a method of graft polymerization of the polyolefin resin and the silane compound, a solution method, a melting method, a polymerization method, or the like may be used. Melting is a method in which an organic material such as a silane compound is directly mixed with a polymer resin in a molten state, which is most preferable from a commercial point of view.

The step (S1) may be performed using an initiator in the range of 0.1 parts by weight to 1 part by weight, preferably 0.5 parts by weight to 0.75 parts by weight, based on 100 parts by weight of the polyolefin resin.

Formula 4 illustrates a process in which a silane compound and a polyolefin resin are grafted to form a modified polyolefin resin, and Formula 5 illustrates an example of a typical modified polyolefin resin.

[Formula 4]

[Formula 5]

Next, the modified polyolefin resin prepared in step (S1) is added to the polyolefin resin and mixed.

Through this step, the modified polyolefin resin is dispersed in the polyolefin resin to improve the dispersibility of the POSS in the polyolefin resin. This step may be achieved by melt-mixing the polyolefin-based resin and the modified polyolefin-based resin.

Next, POSS molecules are added and mixed to the polyolefin resin in which the modified polyolefin resin is dispersed. Through this step, the POSS molecules may be dispersed in the polyolefin resin to obtain a polyolefin nanocomposite of the present invention having excellent physical properties such as heat resistance and modulus. Mixing of the POSS molecules and the polyolefin-based resin of this step can be typically made by melt mixing.

Since the appropriate temperature and time required for the melt-mixing reaction can be made by a known method known to those skilled in the art to which the present invention belongs, detailed description thereof will be omitted.

In addition, the type and content ratio of the components required in the step (S1), (S2) and (S3) is the same as described above.

The polyolefin-based nanocomposites of the present invention have excellent compatibility between the POSS molecules and nonpolar polyolefin-based resins, so that the agglomeration of the POSS molecules is small and the dispersibility is high, and thus the physical properties such as heat resistance and modulus are excellent.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are used only for the purpose of illustrating the present invention and should not be construed as limiting the present invention.

Example  One

100 parts by weight of polypropylene (MI (melting index): 8 / min (ASTM D1238), Tm (melting point): 165 ° C, block polypropylene), 10 parts by weight of vinyltrimethoxysilane, 0.75 parts by weight of dicumyl peroxide as an initiator The mixture was melt mixed at 180 ° C. for 10 minutes to prepare a modified polypropylene.

Example  2

0.1 parts by weight of the modified polypropylene prepared in Example 1 was added to 100 parts by weight of polypropylene, followed by melt mixing for 5 minutes, followed by melt mixing at 180 ° C. for 10 minutes using 1 part by weight of glycidylisobutyl-POSS. Prepared.

Example  3

0.3 parts by weight of the modified polypropylene prepared in Example 1 was added to 100 parts by weight of polypropylene, followed by melt mixing for 5 minutes, followed by melt mixing at 180 ° C. for 10 minutes using 1 part by weight of glycidylisobutyl-POSS. Prepared.

Example  4

0.5 parts by weight of the modified polypropylene prepared in Example 1 was added to 100 parts by weight of polypropylene, followed by melt mixing for 5 minutes, followed by melt mixing at 180 ° C. for 10 minutes using 1 part by weight of glycidylisobutyl-POSS. Prepared.

Example  5

1 part by weight of the modified polypropylene prepared in Example 1 was added to 100 parts by weight of polypropylene, followed by melt mixing for 5 minutes, followed by melt mixing at 180 ° C. for 10 minutes using 1 part by weight of glycidylisobutyl-POSS. Prepared.

Comparative example  One

100 parts by weight of polypropylene and 1 part by weight of glycidyl isobutyl-POSS were melt mixed at 180 ° C. for 10 minutes to prepare a nanocomposite.

Comparative example  2

100 parts by weight of polypropylene and 5 parts by weight of glycidyl isobutyl-POSS were melt mixed at 180 ° C. for 10 minutes to prepare a nanocomposite.

<Property evaluation method>

The structure of the modified polypropylene in which the polypropylene and the silane compound were graft-polymerized was analyzed using IR (wave number 4000-400 Cm ⁻¹ ). 1 is an IR spectrum of the modified polypropylene prepared in Example 1 and the nanocomposite prepared in Example 3. The modified polypropylene prepared in Example 1 showed a peak of silane at 1080Cm ⁻¹ , indicating that the polypropylene and silane were graft-polymerized, and the nanocomposite prepared in Example 3 had a silane at about 1100Cm ⁻¹ . The peaks showed that the modified polypropylene was contained in the nanocomposite. The silane peak of Example 3 and the silane peak of Example 1 are somewhat different because they are affected by the POSS molecules dispersed in the nanocomposite.

In the morphology analysis, the melt-mixed sample was prepared at 180 ° C. using a hot press, and then immersed in liquid nitrogen, and then fractured to confirm the fracture surface using SEM.

2 is an SEM photograph of the nanocomposite prepared according to Example 2, and FIG. 3 is an SEM photograph of the nanocomposite prepared according to Comparative Example 2. FIG. Comparing FIG. 2 with FIG. 3, in Example 2, it can be seen that dispersion is well performed without aggregation of POSS. In Comparative Example 2, it can be seen that POSS is aggregated. Through this, when the nanocomposite was prepared using the modified polyolefin resin as a compatibilizer, it was confirmed that the compatibility and dispersibility of the POSS and the polyolefin resin were improved.

The modulus was measured by DMA using the KS M ISO 6721-4: 2003 method after preparing the specimen at 180 ° C. using a small injection molding machine.

Looking at the modulus graph of Figure 3 it can be seen that the modulus of Example 2 is the highest. This may be because the polypropylene and the POSS do not aggregate with each other and the dispersibility is improved as confirmed in the SEM photograph of FIG. 2.

Tg was measured using a thermogravimetric analyzer under a nitrogen gas purge at an initial temperature of 80 ° C. up to 600 ° C. at a rate of 10 ° C./min, and the results are shown in FIG. 5. As the content of the POSS molecules increases, the Tg temperature increases. This is due to the improved dispersibility of POSS molecules and polypropylene.

Tm and Tc were measured under a nitrogen gas purge up to 250 ° C. at a rate of 10 ° C./min using DSC, and the results are shown in FIGS. 6 and 7.

Through the measurement results of Tm and Tc shown in FIGS. 6 and 7, the physical properties of Examples 3 and 5 are slightly improved when compared to general polypropylene, but Comparative Examples 1 and 2 are inferior in physical properties. there was. This is interpreted as a phase separation phenomenon due to heterogeneous components.

From the above experimental results, it was confirmed that when the modified polypropylene prepared in Example 1 was used as a compatibilizer, a result corresponding to the purpose of nanocomposite production could be obtained.

1 is an IR spectral graph analyzing the structure of the modified polypropylene prepared in Example 1 and the nanocomposite prepared in Example 3.

2 is a SEM photograph of the nanocomposite prepared in Example 2.

3 is a SEM photograph of the nanocomposite prepared in Comparative Example 2.

Figure 4 is a graph showing the analysis of the polypropylene and the modulus of the nanocomposites prepared in Example 2, Example 3, Comparative Example 1 and Comparative Example 2.

5 shows Tg graphs of the nanocomposites prepared in Examples 2, 3, 4 and 5 and polypropylene.

Figure 6 shows the Tm graph of the nanocomposites prepared in polypropylene and Example 3, Example 5, Comparative Example 1 and Comparative Example 2.

Figure 7 shows the Tc graph of the nanocomposites prepared in polypropylene and Example 3, Example 5, Comparative Example 1 and Comparative Example 2.

Claims (19)

Polyolefin resin; POSS molecules dispersed in the polyolefin resin; And Modified polyolefin resins prepared by graft polymerization of polyolefin resins and silane compounds as compatibilizers; Including; The content of the modified polyolefin resin is 0.1 parts by weight to 1 part by weight based on 100 parts by weight of the polyolefin resin, The content of the POSS molecule is 1 to 10 parts by weight relative to 100 parts by weight of the polyolefin resin, The modified polyolefin-based resin is a polyolefin-based nanocomposite consisting of graft polymerization of 100 parts by weight of polyolefin resin and 1 to 10 parts by weight of silane compound. The method of claim 1, The polyolefin-based resin is a polyolefin-based nanocomposite is selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin. delete delete The method of claim 1, The polyolefin-based resins used in the production of the modified polyolefin-based resin is selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin. The method of claim 1, The silane compound is a polyolefin-based nanocomposite represented by the formula (1). [Formula 1]

Here, R ₁ is an alkyl group having 1 to 10 carbon atoms or an alkoxy group, halogen group or aryl group having 1 to 10 carbon atoms. R <_2> is a C1-C10 functional group containing a vinyl group or an acryl group at the terminal group. The method of claim 1, The POSS molecule is a polyolefin-based nanocomposite represented by the following formula (2). [Formula 2]

Wherein R ₃ is an alkyl group having 1 to 10 carbon atoms, an alkene group, an aryl group, an alkoxy group, a cycloalkane group or a halogen group, and R ₄ is a functional group of an oxide having 1 to 10 carbon atoms, a hydroxyl group or a glycidyl group to be. delete (S1) graft polymerizing the polyolefin resin and the silane compound to prepare a modified polyolefin resin, (S2) adding and mixing the modified polyolefin resin to a polyolefin resin, (S3) adding and mixing the POSS molecules to the product produced through the step (S2). Including; The amount of the silane compound used in the step (S1) is characterized in that 1 to 10 parts by weight relative to 100 parts by weight of the polyolefin resin used in the (S1) step, The amount of the modified polyolefin resin used in the step (S2) is 0.1 parts by weight to 1 part by weight relative to 100 parts by weight of the polyolefin resin used in the step (S2), The amount of the POSS molecules used in the step (S3) is 1 to 10 parts by weight based on 100 parts by weight of the polyolefin resin used in the step (S2) polyolefin nanocomposite manufacturing method. The method of claim 9, The polyolefin-based resin used in the step (S1) is a polyolefin-based nanocomposite manufacturing method selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin. The method of claim 9, The polyolefin resin used in the step (S2) is a polyolefin-based nanocomposite manufacturing method is selected from the group consisting of polyethylene resin, polypropylene resin, polyacetylene resin and polyisobutylene resin. delete The method of claim 9, The silane compound is a polyolefin-based nanocomposite manufacturing method represented by the formula (1). [Formula 1]

Here, R ₁ is an alkyl group having 1 to 10 carbon atoms or an alkoxy group, halogen group or aryl group having 1 to 10 carbon atoms. R <_2> is a C1-C10 functional group containing a vinyl group or an acryl group at the terminal group. The method of claim 9, Wherein (S1) step is to proceed using an initiator in the range of 0.1 to 1 parts by weight relative to 100 parts by weight of the polyolefin resin. The method of claim 9, The step (S2) is a method for producing a polyolefin-based nanocomposite that is made by melting and mixing the modified polyolefin-based resin and the polyolefin-based resin produced in the (S1) step. delete The method of claim 9, The step (S3) is a method for producing a polyolefin-based nanocomposite, characterized in that by melting and mixing the product and the POSS molecules in the step (S2). delete The method of claim 9, The POSS molecule is a polyolefin-based nanocomposite manufacturing method represented by the following formula (2). [Formula 2]

Here, R ₃ is an alkyl group having 1 to 10 carbon atoms, an alkene group, an aryl group, an alkoxy group, a cycloalkane group or a halogen group, and R ₄ is a functional group of an oxide having 1 to 10 carbon atoms, hydroxyl group or glycidyl group.

Images