KR20190068207A - A analyzing Method for Branch of Polybutadiene - Google Patents

Abstract

According to the present invention, provided is an analysis method which quantitatively analyzes the content of branches attached to a main chain using an NMR spectrum. According to the present invention, by hydrogenating polybutadiene, an LLDPE analogue similar to a linear low-density polyethylene (LLDPE) structure composed of ethylene-co-1-butene is prepared after removing the double bonds included in the main chain of the polybutadiene to measure the NMR spectrum, so that the content of branches attached to the main chain can be quantitatively analyzed. Therefore, an objective of the present invention is to provide a quantitative analysis method of a long chain branch (LCB) and a short chain branch (SCB) included in polybutadiene.

Description

[0001] The present invention relates to a method for analyzing polybutadiene,

The present invention relates to a method for analyzing branches contained in polybutadiene.

Polybutadiene rubber (BR) consists of microstructure of 1,4-butadiene (Cis / Trans) and 1,2-butadiene (Vinyl). The factors affecting the properties of BR are microstructure ratio, and the double vinyl structure shows various contents according to the polymerization condition.

Branches that can be created in BR can be divided into two types. BR's short chain branch (SCB) means a branch created by microstructure difference like vinyl structure, and long chain branch (LCB) means that polymer main chain itself is short or long connected from branch point of main chain .

In general, the LCB in BR used in tire manufacturing can help the process to be incorporated quickly and stably in the rubber matrix during compounding. In addition, highly linear BRs can exhibit cold flow or creep characteristics, which may flow or deform at external temperatures due to external forces. LCB in BR is known to reduce this phenomenon.

A problem to be solved by the present invention is to provide a quantitative analysis method of long chain branch (LCB) and short chain branch (SCB) contained in polybutadiene.

In order to solve the problems of the present invention,

Hydrogenating polybutadiene; And

And quantitatively analyzing the content of long chain branch (LCB) and short chain branch (SCB) contained in the hydrogenated polybutadiene using an NMR spectrum.

According to one embodiment, the NMR spectrum may be ¹³ C-NMR spectrum.

According to one embodiment, the LCB (long chain branch) may be a branch having a carbon number of 6 or more.

According to one embodiment, the hydrogenation of the polybutadiene may comprise hydrogenating the polybutadiene under a hydrogenation catalyst at high temperature and pressure to remove the double bond.

According to one embodiment, the catalyst may have a structure represented by the following formula (1).

[Chemical Formula 1]

(R _p Z) _r RhX _q

In Formula 1,

R is a C 1 -C 8 -alkyl group, a C 4 -C 8 -cycloalkyl group, a C 6 -C 15 -aryl group or a C 7 -C 15 -aralkyl group and Z is at least one of phosphorus (P), arsenic (As), sulfur (S) (S = O), X is hydrogen or a halide ion, p is an integer of 2 to 3, r is an integer of 2 to 4,

q is an integer of 1 to 3;

According to one embodiment, the hydrogenation reaction is performed by further adding a cocatalyst, and the cocatalyst may include a structure represented by the following formula (2).

(2)

R _p Z

In Formula 2,

R is a C 1 -C 8 -alkyl group, a C 4 -C 8 -cycloalkyl group, a C 6 -C 15 -aryl group or a C 7 -C 15 -aralkyl group and Z is at least one of phosphorus (P), arsenic (As), sulfur (S) Group (S = O), and p is an integer of 2 to 3.

According to one embodiment, in the step of quantitatively analyzing the content of long chain branch (LCB) and short chain branch (SCB) contained in hydrogenated polybutadiene using NMR spectroscopy, NMR (Nuclear Magnetic Resonance) May be used together.

According to one embodiment, the pulse program may be a ¹ H pulse program or a ¹³ C pulse program.

The present invention relates to a process for producing a LLDPE analogue similar to an LLDPE (linear low-density polyethylene) structure consisting of ethylene-co-1-butene after hydrogenating polybutadiene to remove double bonds contained in the main chain of polybutadiene, By measuring the spectrum, the content of branch bonded to the main chain can be quantitatively analyzed using NMR spectrum.

1 shows a ¹³ C-NMR spectrum of BR (polybutadiene rubber).
2 is a graph comparing ¹ H-NMR spectrum before and after hydrogenation of BR (polybutadiene rubber).
3 shows a ¹³ C-NMR spectrum of a linear low-density polyethylene (LLDPE) analogue obtained from the hydrogenation of polybutadiene rubber (BR).

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The Vinyl structure, which is short chain branch (SCB) of polybutadiene rubber (BR), is distinguishable from the Cis / Trans structure, which is the main chain structure of polybutadiene in the ¹ H NMR spectrum. , It is impossible to qualitatively and quantitatively analyze LCB using ¹ H NMR or ¹³ C NMR spectroscopy.

In order to solve such conventional problems, the present invention provides an analytical method for analyzing the content of branches after hydrogenating polybutadiene rubber.

According to the present invention,

Hydrogenating polybutadiene; And

And quantitatively analyzing the content of long chain branch (LCB) and short chain branch (SCB) contained in the hydrogenated polybutadiene using an NMR spectrum.

The present invention relates to a process for producing polybutadiene rubber by hydrogenating a polybutadiene rubber to remove a double bond contained in a main chain of a polybutadiene and then forming a linear low density polyethylene (LLDPE) structure comprising ethylene-co-1-butene LLDPE < / RTI > analogs similar to those described above can be prepared, and then the content of branches bonded to the backbone can be analyzed using NMR spectra.

[Reaction Scheme]

The present invention can be obtained not only by separating the peaks of SCB and LCB on the spectrum using LLDPE branching analysis method by using LLDPE analogs for quantitative analysis, but also by peaks of the main chain of LCB and LLDPE analogues And the amount of LCB contained in polybutadiene can be quantified.

In this case, LCB can be defined as a branch having a C6 branch and a carbon number higher than that produced by a 1-octene comonomer.

According to one embodiment, the NMR spectroscope that may be used in the quantitative analysis may be a ¹³ C-NMR spectroscope.

The method of quantifying the LLDPE analogue using a ¹³ C-NMR spectrometer is, for example,

The methylene carbon present in the main chain of the LLDPE analog is observed near the chemical shift δ = 30 ppm in ¹³ C-NMR, and the methyl carbon at the branching end in the branching point of C6 can appear near δ = 14.26 ppm, In the case of δ = 11.34 ppm. Therefore, in the case of the branch of C6, the relative value of the area of the peak of methyl carbon appearing near the chemical shift? = 14.06 ppm relative to the area of the peak of the methylene carbon of the main chain observed near? = 30 ppm can be evaluated to evaluate the quantitation , And in the case of the branch of C2, the relative value of the peak area of methyl carbon appearing near the chemical shift δ = 11.34 ppm relative to the area of the peak of the methylene carbon of the main chain observed near δ = 30 ppm can be calculated to evaluate the quantification .

According to one embodiment, the hydrogenation of the polybutadiene rubber may include a step of hydrogenating the polybutadiene under a hydrogenation catalyst at a high temperature and a high pressure to remove double bonds.

At this time, in the process for hydrogenating the polybutadiene, the pressure condition may be 30 to 60 bar, preferably 40 to 60 bar.

In the process for hydrogenating the polybutadiene, the reaction temperature may be from 100 to 150 ° C, preferably from 100 to 130 ° C, and the reaction time is from 20 to 40 hours, preferably from 20 to 30 hours, Lt; / RTI > time.

As the catalyst for hydrogenation, a hydrogenation catalyst generally used for hydrogenation may be used. More specifically, a catalyst having a structure represented by the following formula (1) may be used.

[Chemical Formula 1]

(R _p Z) _r RhX _q

In Formula 1,

R is a C 1 -C 8 -alkyl group, a C 4 -C 8 -cycloalkyl group, a C 6 -C 15 -aryl group or a C 7 -C 15 -aralkyl group,

Z is phosphorus (P), arsenic (As), sulfur (S), or sulfoxide group (S = O)

X is hydrogen or a halide ion,

p is an integer of 2 to 3,

r is an integer of 2 to 4,

q is an integer of 1 to 3;

Examples of suitable catalysts having the structure of Formula 1 include tris (triphenylphosphine) rhodium (I) chloride ((PPh ₃ ) ₃ RhCl), tris (triphenylphosphine) rhodium III) chloride _{((PPh 3) 3 RhCl 3} ) and tris (dimethyl sulphoxide) rhodium (III) chloride, and the formula _{((C 6 H 5) 3} P) in ₄ RhH tetrakis (triphenylphosphine ) -Rhodium hydride, and a compound wherein the triphenylphosphine residue is substituted with a tricyclohexylphosphine residue. The catalyst may be used in a small amount, for example, from 0.10 parts by weight to 50 parts by weight, preferably from 2.0 parts by weight to 10 parts by weight, based on 100 parts by weight of polybutadiene.

Further, the catalyst may be used together with a cocatalyst, and more particularly, a cocatalyst including a structure of the following formula (2) may be used together.

(2)

R _p Z

In Formula 2,

R is a C 1 -C 8 -alkyl group, a C 4 -C 8 -cycloalkyl group, a C 6 -C 15 -aryl group or a C 7 -C 15 -aralkyl group,

Z is phosphorus (P), arsenic (As), sulfur (S), or sulfoxide group (S = O)

p is an integer of 2 to 3;

Preferably, R and Z may be the same as those used for the catalyst.

The cocatalyst may be used in an amount of 0.38 to 190 parts by weight, preferably 7.6 to 38 parts by weight based on 100 parts by weight of polybutadiene.

The organic solvent used in the hydrogenation process is not particularly limited as long as it is used in a hydrogenation process, for example, linear and branched chain hydrocarbons such as pentane, hexane, heptane and octane, and alkyl-substituted derivatives thereof; Alicyclic hydrocarbons such as cyclopentane, cyclohexane and cycloheptane, and alkyl-substituted derivatives thereof; Aromatic and alkyl-substituted aromatic hydrocarbons such as benzene, naphthalene, toluene and xylene; Hydrogenated aromatic hydrocarbons such as tetralin and decalin; One or more organic solvents selected from straight-chain and cyclic ethers such as dimethyl ether, methyl ethyl ether, diethyl ether and tetrahydrofuran can be used, and preferably aromatic and alkyl-substituted solvents such as benzene, naphthalene, toluene and xylene, Organic solvents selected from substituted aromatic hydrocarbons may be more suitable.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

≪ Comparative Example 1 &

The ¹³ C NMR spectrum of a polybutadiene rubber (BR) containing SCB having 2 carbon atoms and LCB having 6 or more carbon atoms was measured and is shown in FIG.

≪ Example 1 >

The BR of Comparative Example 1 was hydrogenated under the conditions shown in Table 1 to prepare an LLDPE (Linear Low-density polyethylene) analogue. The results of ¹ H NMR measurement of the obtained LLDPE analog are shown in FIG. From the ¹ H NMR spectrum of FIG. 2, it can be judged whether the BR hydrogenation process has proceeded properly (all hydrogenation). From this, it can be confirmed whether BR is structurally modified to LLDPE analogue.

BR 480 mg catalyst (PPh _{3) 3} RhCl 0.03 mmol Co-catalyst PPh ₃ 0.40 mmol menstruum Toluene 50 ml Hydrogenation pressure 50 bar Reaction temperature and time 110 ° C, 24 hrs

In FIG ¹ H NMR of the second group of the branch ends of a hydrogenated BR (-CH ₃₎ is smaller, albeit appear, ¹ H NMR spectrum the problems due to peak overlap of SCB and LCB that can accurately quantify the amount of SCB and LCB And the -CH and -CH ₂ groups included in the main chain and the branch are not distinguished from each other. Therefore, it is difficult to quantitatively analyze the branch with ¹ H NMR alone.

Therefore, in order to quantitatively analyze LLDPE, ¹³ C NMR measurement is required in addition to ¹ H NMR.

The ¹³ C NMR spectrum of the LLDPE analog was measured for LLDPE quantitative analysis and is shown in FIG.

In the result of the ¹³ C NMR spectrum of FIG. 3, the -CH ₂ and -CH ₂ groups of the branch and main chain are distinguished, and the peaks related to LCB and SCB are also distinguished. Therefore, the LCB content can be quantified by integrating the peaks of the methyl groups at the ends of the LCB and the SCB to calculate the relative value to the methylene peak of the main chain. The results of calculating the contents of SCB and LCB using the ¹³ C NMR spectrum of FIG. 3 are shown in Table 2 below.

More specifically, the quantitative analysis of the polybutadiene branch from the ¹³ C NMR measurement results of FIG. 3 can be carried out using the following calculation method.

When the integrated value of the main chain carbon, 30 ppm, is fixed at 1000, the integrated value of 11.3 ppm is called A and the integrated value of 14.3 ppm is called B.

1) Calculating the relative mole ratio between branches

When the integration value of main chain carbon is normalized to 1000, the integral value of each branch represents the relative mole ratio between them.

Therefore, the relative mole ratio between branches can be obtained as shown in Equation 1 below.

[Formula 1]

SCB: LCB = A: B = 6.76: 1.68

2) Calculation of each branch number (X) per 1000 main chain carbon

In the main chain, the total number of carbons contributed by each branch is 5 (2α + 2β + *), and the carbon number of the main chain can be obtained as shown in Equation 2 below.

[Formula 2]

(1000 - A - B) + 5 * (A + B)

Therefore, the number of _SCBs (X _SCB ) present per 1000 main chain carbon atoms can be obtained as shown in Equation 3 below,

[Formula 3]

(1000 - A - B) + 5 * (A + B): A = 1000: X _SCB X _SCB = 6.54

The number of _LCBs (X _LCB ) present per 1000 main chain carbon can be obtained as shown in Equation 4 below.

[Formula 4]

(1000 - A - B) + 5 * (A + B): B = 1000: X _LCB X _LCB = 1.63

3) Calculate the relative mole ratio (Y) between ethylene and each branch

Using the number of SCB and LCB obtained from the above Equation 3 and Equation 4, the relative mole ratio between ethylene and each branch contained in the main chain can be obtained as shown in Equation 5 below.

[Formula 5]

_{Y Et: Y SCB: Y LCB} = {1000 - 2 * (X SCB + X LCB)} / 2: X SCB: X LCB

= 491.84: 6.54: 1.63

4) Relative mass ratio (Z) between ethylene and each branch

The relative mass ratio between ethylene and each branch can be obtained as shown in Equation (6) using the relative mole ratio between ethylene and each branch obtained in Equation (5).

^{In the 13} C NMR, branches of C6 or more are structurally similar regardless of the number of carbons, so that they can not be distinguished from each other because they show the same chemical shift. Therefore, LCB was considered as C6 branch and analyzed.

[Formula 6]

Z _Et : Z _SCB : Z _LCB = Y _Et * 28: Y _SCB * 56: Y _LCB * 112

= 366.20: 182.02: 13771.40

5) Branch wt%

The content of SCB and LCB contained in BR can be analyzed based on the relative mass ratio between ethylene and each branch obtained in Equation 6 above.

The content of SCB can be obtained as shown in Equation 7 below,

[Equation 7]

SCB wt% = Z _SCB / (Z _Et + Z _SCB + Z _LCB ) * 100 = (366.20 / 14319.61) * 100

= 2.6 wt%

The content of LCB can be obtained as shown in the following formula (8).

[Equation 8]

LCB wt% = Z _LCB / (Z _Et + Z _SCB + Z _LCB ) * 100 = (182.02 / 14319.61) * 100

= 1.3 wt%

BR Component Ratio (wt%) SCB 2.5 LCB 1.3 Ethylene 96.2

The present invention, by measuring the ¹³ C NMR and then hydrogenating the polybutadiene, it is possible to obtain a ¹³ C NMR spectrum appearing peak is divided in the main chain and branched, the content of long chain branching (LCB) comprising therefrom on polybutadiene It can be quantified.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (8)

Hydrogenating polybutadiene; And
And quantitatively analyzing the content of long chain branch (LCB) and short chain branch (SCB) contained in the hydrogenated polybutadiene by NMR spectroscopy. The method according to claim 1,
Wherein the NMR spectrum is a < ¹³ > C-NMR spectrum of the polybutadiene branch. The method according to claim 1,
Wherein the LCB (long chain branch) is a branch having a carbon number of 6 or more. The method according to claim 1,
Wherein the step of hydrogenating the polybutadiene comprises hydrogenating the polybutadiene under a hydrogenation catalyst at high temperature and pressure to remove double bonds. 5. The method of claim 4,
Wherein the catalyst comprises a structure represented by the following formula (1): < EMI ID =
[Chemical Formula 1]
(R _p Z) _r RhX _q
In Formula 1,
R is a C 1 -C 8 -alkyl group, a C 4 -C 8 -cycloalkyl group, a C 6 -C 15 -aryl group or a C 7 -C 15 -aralkyl group,
Z is phosphorus (P), arsenic (As), sulfur (S), or sulfoxide group (S = O)
X is hydrogen or a halide ion,
p is an integer of 2 to 3,
r is an integer of 2 to 4,
q is an integer of 1 to 3; 5. The method of claim 4,
Wherein the step of hydrogenating the polybutadiene is carried out by further adding a cocatalyst, and the cocatalyst comprises a structure of the following formula (2): < EMI ID =
(2)
R _p Z
In Formula 2,
R is a C 1 -C 8 -alkyl group, a C 4 -C 8 -cycloalkyl group, a C 6 -C 15 -aryl group or a C 7 -C 15 -aralkyl group,
Z is phosphorus (P), arsenic (As), sulfur (S), or sulfoxide group (S = O)
p is an integer of 2 to 3; The method according to claim 1,
(Nuclear Magnetic Resonance) spectrometer and pulse program are used together in the quantitative analysis of the content of long chain branch (LCB) and short chain branch (SCB) contained in the hydrogenated polybutadiene using NMR spectrum Analysis method of polybutadiene branch. 8. The method of claim 7,
Wherein the pulse program is a ¹ H pulse program or a ¹³ C pulse program.

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