JPH037685B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a styrenic polymer having a novel steric structure, and more particularly to a styrenic polymer in which the stereochemical structure of the side chain relative to the main chain of the polymer is mainly a syndiotactic structure. [Prior art and problems to be solved by the invention] In general, styrenic polymers such as polystyrene and polyparamethylstyrene can be produced by radical polymerization, anionic polymerization, cationic polymerization, or polymerization using a Ziegler type catalyst. It has been known. The structure of the styrenic polymer thus obtained is theoretically classified into isotactic structure, syndiotactic structure and atactic structure, depending on the configuration of the molecular chains. So far, it has been reported that conventional radical polymerization, anionic polymerization, and cationic polymerization mainly yield styrenic polymers with an atactic structure, and polymerization using a Ziegler type catalyst mainly yields styrene polymers with an isotactic structure. Are known. As described above, although many methods of producing styrenic polymers and their structures have been reported to date, there is no example of a styrenic polymer having a highly syndiotactic structure being produced. Namely, Makromol.Chem., Rapid Commun.3,
661-665 (1982), 54% in racemic diats
Polystyrene is described, but this polystyrene is in an almost disordered state (non-crystalline) in which racemic and meso polystyrenes exist, and even when converted to racemic pentads, the proportion is only 8.5%. [Means for Solving the Problems] Therefore, the present inventors conducted repeated research in order to produce a styrenic polymer having a highly syndiotactic structure, which has never been produced before. As a result, when styrenic monomers are polymerized using a catalyst that combines a certain type of transition metal compound and an organometallic compound, a styrenic polymer with a structure that has never been obtained before is surprisingly obtained. It was found that this material has a highly syndiotactic structure, leading to the completion of the present invention. That is, the present invention is based on the general formula () [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms, and the substituent position of R is p
- position and/or m-position, and n represents an integer of 1 to 3. ] Polymerization degree 10~ having repeating units represented by
100,000, and its tacticity is 30% for racemic pentads according to ¹³ C-NMR.
The present invention provides a styrenic polymer having a syndiotactic structure as described above. The styrenic polymer in the present invention has a structural unit (repeat unit) represented by the above general formula (), and includes various nuclear-substituted polystyrenes such as polystyrene, polyalkylstyrene, and polyhalogenated styrene. R and n in the above general formula () are as described above. That is, the nuclear substituent (R) is a hydrogen atom, a halogen atom such as chlorine, bromine, or iodine, or an alkyl group having 1 to 20 carbon atoms (for example, a methyl group,
ethyl group, isopropyl group, tert-butyl group, etc.). Further, specific examples of the styrenic polymer of the present invention include polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(3,4
-dimethylstyrene), poly(3,5-dimethylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene), poly( p-bromostyrene), poly(m-bromostyrene), poly(p-fluorostyrene),
Examples include poly(halogenated styrene) such as poly(m-fluorostyrene). The styrenic polymer of the present invention has a syndiotactic structure, that is, a three-dimensional structure in which side chain phenyl groups or substituted phenyl groups are alternately located in opposite directions with respect to the main chain formed from carbon-carbon bonds. Its tacticity is determined by nuclear magnetic resonance method (NMR method). ^Specifically , _C1 carbon signal of aromatic ring, methine/methylene carbon signal, or
Based on ¹ H-NMR proton signal analysis.
Tacticity measured by NMR is the proportion of consecutive constituent units present; for example, two units are diads, three units are triads,
In the case of 5 atoms, it can also be expressed as a pentad, but in general, the polymer having a syndiotactic structure referred to in the present invention is a racemic diamond with 75% of the structure.
or 30% or more of racemic pentads, preferably 50% or more of racemic pentads. here,
Racemic pentad refers to five consecutive repeating units represented by the above general formula, in other words, a racemic unit (r)

〔Effect of the invention〕

As described above, the styrenic polymer of the present invention has an unprecedentedly regular molecular structure, and when it crystallizes, it has significantly better heat resistance than the commonly used atactic polystyrene. It also has excellent chemical resistance and can be used as a molding material in various fields where these are required. Moreover, those having a functional substituent introduced into the side chain benzene ring are effectively and widely used as functional polymers. [Example] Next, Examples of the present invention will be shown, and it will be confirmed that the obtained styrenic polymer mainly shows a syndiotactic structure. Example 1 (1) Preparation of catalyst components 47.4 ml (492 mmol) of trimethylaluminum was added to 200 ml of toluene solvent, and 35.5 g of copper sulfate pentahydrate (CuSO ₄ .5H ₂ O) was added thereto.
(142 mmol) and allowed to react at 20°C for 24 hours. After the reaction is complete, the solvent toluene is removed by filtration, and methylaluminoxane 12.4
I got g. (2) Production of polystyrene In a glass container with an internal volume of 500 ml and equipped with a stirrer, add 100 ml of toluene and 40 mmol of methylaluminoxane obtained in (1) above as aluminum atoms, and then add 0.05 mmol of cyclopentadienyl titanium trichloride. added. Subsequently, 180 ml of styrene was added at 20°C to carry out a polymerization reaction for 1 hour, and then methanol was injected to stop the reaction. Next, a mixture of hydrochloric acid and methanol was added to decompose the catalyst components. The yield of the polystyrene obtained here was 16.5 g, and the weight average molecular weight was 280,000 and the number average molecular weight was 57,000. Furthermore, this polystyrene was extracted using a Soxhlet extractor for 4 hours using methyl ethyl ketone as a solvent.
97wt% was insoluble. Furthermore, the melting point of this methyl ethyl ketone-insoluble polystyrene was 260°C, and the specific gravity was 1.043. The aromatic ring C ¹ carbon signal of this methyl ethyl ketone-insoluble _polystyrene (130°C in 1,2,4-trichlorobenzene solvent) is shown in Figure 1a, and ¹³ C-NMR (1,2, The methine/methylene carbon signal in 4-trichlorobenzene solvent at 130°C is shown in Figure 2a, ^{the 1} H-NMR (proton nuclear magnetic resonance spectrum) is shown in Figure 3a, and the X
The line diffraction pattern is shown in Figure 4a, and the infrared absorption spectrum is shown in Figure 5a. Comparative Example 1 Atactic polystyrene obtained by radical polymerization of styrene at 0° C. using organic peroxide was extracted with methyl ethyl ketone in the same manner as in Example 1 (2), and the entire amount was extracted. Further, this polystyrene had a glass transition temperature of 100°C and a specific gravity of 1.05. The aromatic ring _C1 carbon signal of this polystyrene in ^13C -NMR is shown in Figure 1b, the methine/methylene carbon signal in ^13C -NMR is shown in Figure 2b, and the infrared absorption spectrum is shown in Figure 5b. show. Comparative Example 2 10.0 g of magnesium diethoxide was reacted with 50 ml of titanium tetrachloride, and a combination of 1.0 mmol of a titanium catalyst component supporting a titanium compound and 10 mmol of triethylaluminum was used as a catalyst.
100 ml of styrene for 2 hours at 70°C in heptane solvent
A polymerization reaction was carried out to obtain 48.7 g of isotactic polystyrene having a weight average molecular weight of 1,000,000. When this polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 1 (2), 96 wt% was found to be insoluble. The aromatic ring C1 carbon signal of ¹³ C _- NMR of this methyl ethyl ketone-insoluble polystyrene is shown in Figure 1 c, the methine/methylene carbon signal of ¹³ C-NMR is shown in Figure 2 c, and ¹ H-NMR is shown in Figure 3. Diagram b
The X-ray diffraction pattern is shown in Figure 4b, and the infrared absorption spectrum is shown in Figure 5c. Next, it was determined that the polystyrene obtained in Example 1 (2) has a syndiotactic structure based on the analysis results of this polystyrene, the atactic polystyrene obtained in Comparative Example 1, and the atactic polystyrene obtained in Comparative Example 2.
Confirm by comparing the analysis results of isotactic polystyrene obtained in . (1) ¹³ C-NMR results (i) Aromatic ring C ₁ signal It is well known that the splitting of the aromatic ring C ₁ carbon signal corresponds to the polymer microstructure. Table 1 summarizes the literature values and the measured values for the polystyrene, atactic polystyrene, and isotactic polystyrene obtained in Example 1 (FIG. 1 a, b, c). From Table 1, the polystyrene of Example 1 has a syndiotactic structure and has a tacticity of 96% or more, almost 100%, in racemic pentads, calculated from the peak area in Figure 1a. Ta.

【table】

[Table] (ii) Methine/methylene carbon signal Methine/methylene carbon signal splitting is
It is well known that this corresponds to the microstructure of polymers, and in the case of polystyrene, there are many publications reporting the attribution of this splitting. Literature values and actual measured values of polystyrene, atactic polystyrene, and isotactic polystyrene obtained in Example 1 (Fig. 2 a, b,
c) are summarized and shown in Table 2.

【table】

[Table] *1 and *2 are the same as above. The units of numbers in the table are ppm (TMS standard). As is clear from Table 2, the polystyrene obtained in Example 1 is syndiotactic polystyrene, and since it has a single peak, it can be seen that it has syndiotacticity close to 100%. . (2) ¹ H-NMR results It is well known that ¹ H-NMR can provide information on microstructures in the same way as ¹³ C-NMR (S.Brownstein, S.Bywater, D.T.
Worsfold, J.Phys.Chem., 66 , 2067 (1962)). Comparing Figure 3a and b of the polystyrene obtained in Example 1, the methine proton signal of the polystyrene of Example 1 appears in a higher magnetic field than the methine proton of isotactic polystyrene. , which is clearly different from isotactic polystyrene. Furthermore, the polystyrene obtained in Example 1 shows a microstructure, and atactic polystyrene (FABovey,
FPHood, J.Chem.Phys., 38 , 1026
(1963)), only one type of methylene and one type of methylene proton in the molecular chain were observed, so it was determined that the structure was almost 100% syndiotactic. Judging comprehensively from the results of (1) and (2) above, the polystyrene obtained in Example 1 is a polymer with a syndiotactic structure in which the steric structure is 96% or more and close to 100% in the pentad structure. I confirmed that there is. (3) X-ray diffraction pattern The polystyrene obtained in Example 1 shows crystallinity, but the X-ray diffraction pattern of the crystallized product (Figure 4a) and the X-ray diffraction pattern of isotactic polystyrene (Figure 4b) ) (G.Natta, P.
Corradini, Nuovo Cimento 15 , Suppl. 1 , 40
(1960)), the two are markedly different. Therefore, it can be seen that the polystyrene of Example 1 has a different crystal structure from that of isotactic polystyrene. In addition, from the results shown in FIG. 4a, the fiber period of the polystyrene of Example 1 was 5.04 Å. This fiber period suggests a structure in which the polymer chain has a zigzag structure and phenyl rings are arranged alternately. In addition to the NMR results, the polystyrene of Example 1 also supports a syndiotactic structure. That's what I do. (4) Infrared absorption spectrum When the peaks in the graphs in Figure 5 a, b, and c are organized, the results are as shown in Table 3.

[Table] ○...Absorption, ×...No absorption In addition, the polystyrene of Example 1 has a 1220 cm ^-1
There is a unique absorption peak that is not found in polystyrene with isotactic and atactic structures. (5) Melting point The melting point of the polystyrene obtained in Example 1 is
260-270°C, which is much higher than the melting point of isotactic polystyrene (220°C-230°C). (6) Tacticity of extracts of methyl ethyl ketone Generally, when determining stereoregularity in polystyrene, Soxhlet extraction is performed using methyl ethyl ketone as a solvent. It has been determined that it is atactic polystyrene. (Tadashi Nakata, Yasuo Kinoshita, Takayuki Otsu, Minoru Imoto, Industrial Chemistry, 68 , 858-864
(1965)). The methyl ethyl ketone-insoluble part of the polystyrene obtained in Example 1 had a syndiotactic structure, but the methyl ethyl ketone-soluble part was also racemic pentato and had a syndiotactic structure of 82% or more. Example 2 Using 1 mmol of titanium tetrachloride and methylaluminoxane as catalysts, 100 ml of styrene was polymerized at 50°C for 8 hours, and the following procedure was carried out in the same manner as in Example 1 (2) to obtain 0.1 g of polystyrene. The syndiotacticity of the obtained polystyrene was 36% in ¹³ C-NMR racemic pentatats.
The weight average molecular weight (Mw) was 544,000, and the number average molecular weight (Mn) was 223,000. In addition, when this polystyrene was extracted with methyl ethyl ketone, 79 wt% was extracted, and the syndiotacticity of the extracted residue was 86% in racemic pentad in ¹³ C-NMR, and the weight average molecular weight (Mw) was 678,000. Number average molecular weight (Mn)
It was 272,000. The syndiotacticity of the extract was 23% as a racemic pentad in ¹³ C-NMR. Example 3 Polystyrene was produced in the same manner as in Example 2, except that the amount of titanium tetrachloride used as a catalyst component was 0.05 mmol, the amount of styrene used was 180 ml, and the polymerization time was 2 hours. 6.7g
I got it. When this polystyrene was extracted with methyl ethyl ketone, 8% was extracted. The syndiotacticity of the extracted polystyrene was 99% or more as a racemic pentad, and the weight average molecular weight (Mw) was 348,000 and the number average molecular weight (Mn) was 156,000. Example 4 0.4 g of polystyrene was obtained in the same manner as in Example 2, except that 1 mmol of isopropoxytitanium trichloride was used instead of titanium tetrachloride as the catalyst component and the polymerization time was 2 hours. The syndiotacticity of this polystyrene was 96% as a racemic pentad in ¹³ C-NMR, the weight average molecular weight (Mw) was 92,000, and the number average molecular weight (Mn) was 31,000. When this polystyrene was extracted with methyl ethyl ketone, 58 wt% was extracted. The syndiotactic property of the extracted polystyrene is ¹³ C−
Has 96% NMR racemic pentad, weight average molecular weight (Mw) 100000, number average molecular weight (Mn)
It was 36,000. The syndiotacticity of the extract was 23% in pentad. Example 5 Ethoxytitanium trichloride as catalyst
Polystyrene was obtained in the same manner as in Example 2, except that 0.02 mmol and 10 mmol of methylaluminoxane were used and the conditions shown in Table 4 were used. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Example 6 0.2 mmol (as titanium tetrachloride) of titanium tetrachloride supported on magnesium diethoxide (146 mg/g/carrier) and 10 mmol methylaluminoxane were used as a catalyst, and the conditions shown in Table 4 were used. Polystyrene was obtained in the same manner as in Example 2 except for this. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Example 7 0.2 mmol (as tetraethoxytitanium) of tetraethoxytitanium supported on magnesium chloride (80 mg/g/carrier) and 10 mmol methylaluminoxane were used as a catalyst, and the conditions shown in Table 4 were also used. , Polystyrene was obtained in the same manner as in Example 2. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are the fourth
Shown in the table. Example 8 Using a large excess of titanium tetrachloride as a catalyst, the amount of titanium supported on magnesium chloride was 0.02
Polystyrene was obtained in the same manner as in Example 2, except that mmol and 10 mmol of methylaluminoxane were used and the conditions shown in Table 4 were used.
Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Example 9 Example 2 except that titanium tetrachloride and ethyl benzoate were used as catalysts, 0.02 mmol of titanium supported on magnesium chloride and 10 mmol of methylaluminoxane were used, and the conditions shown in Table 4 were used. Polystyrene was obtained in the same manner. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2.
The properties of this polystyrene are shown in Table 4. Example 10 Polystyrene was obtained in the same manner as in Example 2, except that 0.02 mmol of titanium trichloride and 20 mmol of methylaluminoxane were used as catalysts, and the conditions shown in Table 4 were used. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are the fourth
Shown in the table. Example 11 Except for using 1 mmol of titanium tetrachloride, 1 mmol of tributoxyvanadyl (VO(O.C ₄ H ₉ ) ₃ ) and 40 mmol of methylaminoxane as catalysts, and using the conditions shown in Table 4, Example 2
Polystyrene was obtained in the same manner. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Examples 12, 13 Polystyrene was produced in the same manner as in Example 2, except that 1 mmol of isopropoxytitanium chloride, 1 mmol of tributoxyvanadyl, and 40 mmol of methylaminoxane were used as catalysts, and the conditions shown in Table 4 were further adjusted. Obtained. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Examples 14-16 Using 0.05 mmol of tetraethoxytitanium and 5 mmol of methylaluminoxane as a catalyst,
Furthermore, polystyrene was obtained in the same manner as in Example 2, except that the conditions shown in Table 4 were used. after that,
The obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Example 17 Using 0.05 mmol of tetraethoxytitanium and 10 mmol of methylaluminoxane as a catalyst,
Furthermore, polystyrene was obtained in the same manner as in Example 2, except that the conditions shown in Table 4 were used. after that,
The obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Examples 18-20 Using 0.05 mmol of tetraethoxytitanium and 25 mmol of methylaluminoxane as a catalyst,
Furthermore, polystyrene was obtained in the same manner as in Example 2 except that the conditions shown in Table 4 were used. after that,
The obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are shown in Table 4. Example 21 Polystyrene was obtained in the same manner as in Example 2, except that 1 mmol of tetraisopropoxytitanium, 1 mmol of tributoxyvanadyl, and 40 mmol of methylaluminoxane were used as catalysts, and the conditions shown in Table 4 were used. Thereafter, the obtained polystyrene was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this polystyrene are the fourth
Shown in the table. Example 22 Same as Example 2, except that 0.02 mmol of cyclopentadienyl titanium trichloride and 10 mmol of methylaluminoxane were used as the catalyst, styrene p-methylstyrene was used as the raw material monomer, and the conditions shown in Table 4 were used. A copolymer of styrene and p-methylstyrene was obtained in the same manner. Thereafter, the obtained copolymer was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this copolymer are shown in Table 4. Example 23 Using 0.025 mmol of cyclopentadienyl titanium trichloride and 40 mmol of methylaluminoxane as a catalyst, p as a raw material monomer.
- Poly(p-methylstyrene) was obtained in the same manner as in Example 2, except that methylstyrene was used and the conditions shown in Table 4 were used. Thereafter, the obtained poly(p-methylstyrene) was extracted with methyl ethyl ketone in the same manner as in Example 2. This poly(p
-methylstyrene) are shown in Table 4. In addition, the ¹³ C- of this poly(p-methylstyrene)
The NMR aromatic ring _C1 carbon signal is shown in Figure 1d, ¹³
-NMR methine/methylene carbon signal as second
Figure d shows the ¹ H-NMR, Figure 3c shows the X-ray diffraction pattern, Figure 4c shows the infrared absorption spectrum, and Figure 5d shows the infrared absorption spectrum. Example 24 Using 0.05 mmol of cyclopentadienyl titanium trichloride and 30 mmol of methylaluminoxane as a catalyst, m-
Poly(m-methylstyrene) was obtained in the same manner as in Example 2, except that methylstyrene was used and the conditions shown in Table 4 were used. Thereafter, the obtained poly(m-methylstyrene) was extracted with methyl ethyl ketone in the same manner as in Example 2. This poly(m
-methylstyrene) are shown in Table 4. In addition, the ¹³ C- of this poly(m-methylstyrene)
The NMR aromatic ring C ₁ carbon signal is shown in Figure 1e. Example 25 Using 0.05 mmol of cyclopentadienyl titanium trichloride and 30 mmol of methylaluminoxane as a catalyst, p-
Poly(p-t-butylstyrene) was obtained in the same manner as in Example 2, except that t-butylstyrene was used and the conditions shown in Table 4 were used. after that,
The obtained poly(pt-butylstyrene) was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this poly(pt-butylstyrene)
Shown in the table. The aromatic ring C ₁ carbon signal of this poly(pt-butylstyrene) in ¹³ C-NMR is shown in FIG. 1f. Example 26 Using 0.05 mmol of cyclopentadienyl titanium trichloride and 40 mmol of methylaluminoxane as a catalyst, p-
Poly(p-chlorostyrene) was obtained in the same manner as in Example 2, except that chlorostyrene was used and the conditions shown in Table 4 were used. Thereafter, the obtained poly(p-chlorostyrene) was extracted with methyl ethyl ketone in the same manner as in Example 2. This poly(p
-chlorostyrene) are shown in Table 4. In addition, the ¹³ C- of this poly(p-chlorostyrene)
The NMR aromatic ring C ₁ carbon signal is shown in Figure 1g, and for reference, the ¹³ C-NMR aromatic ring C ₁ carbon signal of atactic (p-chlorostyrene) is shown in Figure 1h. Example 27 Using 0.05 mmol of tetraethoxytitanium and 5 mmol of methylaluminoxane as a catalyst,
Using m-chlorostyrene as a raw material monomer,
Furthermore, poly(m-chlorostyrene) was obtained in the same manner as in Example 2, except that the conditions shown in Table 4 were used. Thereafter, the obtained poly(m-chlorostyrene) was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this poly(m-chlorostyrene) are shown in Table 4. The aromatic ring C ₁ carbon signal of this poly(m-chlorostyrene) in ¹³ C-NMR is shown in Figure 1i. Example 28 Using 0.05 mmol of cyclopentadienyl titanium trichloride and 30 mmol of methylaluminoxane as a catalyst, p-
Poly(p-fluorostyrene) was obtained in the same manner as in Example 2, except that fluorostyrene was used and the conditions shown in Table 4 were used. Thereafter, the obtained poly(p-fluorostyrene) was extracted with methyl ethyl ketone in the same manner as in Example 2. The properties of this poly(p-fluorostyrene) are shown in Table 4.
In addition, the ¹³ C of this poly(p-fluorostyrene)
-NMR aromatic ring C ₁ carbon signal is shown in Figure 1j.

【table】

[Table] *1 Indicates racemic pentad *2 Indicates racemic pentad in the styrene structural unit.

[Brief explanation of the drawing]

Figure 1 a to j show the polystyrene obtained in Example 1, the atactic polystyrene obtained in Comparative Example 1, the isotactic polystyrene obtained in Comparative Example 2, and the poly(p) obtained in Example 23, respectively. −
methylstyrene), poly(m
-methylstyrene), poly(p-t-butylstyrene) obtained in Example 25, poly(p-chlorostyrene) obtained in Example 26, atactic poly(p-chlorostyrene), obtained in Example 27. ¹³ C-NMR of the poly(m-chlorostyrene) obtained and the poly(p-fluorostyrene) obtained in Example 28
The aromatic ring C ₁ carbon signal is shown. Figure 2 a-d
are the polystyrene obtained in Example 1, the atactic polystyrene obtained in Comparative Example 1, the isotactic polystyrene obtained in Comparative Example 2, and the poly(p-methylstyrene) obtained in Example 23, respectively. ¹³ C-NMR methine/methylene carbon signals are shown. Figures 3a to 3c show polystyrene obtained in Example 1, isotactic polystyrene obtained in Comparative Example 2, and Example 3, respectively.
^1H of poly(p-methylstyrene) obtained in 23
- Shows NMR. Figures 4 a to c show polystyrene obtained in Example 1, isotactic polystyrene obtained in Comparative Example 2, and Example 23, respectively.
The X-ray diffraction pattern of poly(p-methylstyrene) obtained in is shown. Figures 5 a to d show polystyrene obtained in Example 1, atactic polystyrene obtained in Comparative Example 1, isotactic polystyrene obtained in Comparative Example 2, and Example 5, respectively.
The infrared absorption spectrum of poly(p-methylstyrene) obtained in 23 is shown. In addition, in FIG. 4, θ indicates the Bragg angle (°).

Claims (1)

[Claims] 1 General formula () [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms, and the substituent position of R is p
- position and/or m-position, and n represents an integer of 1 to 3. ] Polymerization degree 10~ having repeating units represented by
100,000, and its tacticity is 30% as a racemic pentad by ¹³ C-NMR.
A styrenic polymer with a syndiotactic structure as described above.