Dilute solution properties of poly(4-hydroxystyrene)

Arichi, Shizuo; Sakamoto, Noriyuki; Yoshida, Masafumi; Himuro, Shozo

doi:10.1016/0032-3861(86)90273-9

Cited by 17 publications

(16 citation statements)

References 36 publications

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“…To place the values of h r in context, we compare the residual film thicknesses to the radius of gyration (R g ) of PHS 41 shown in Table I. For PHS films annealed above the bulk T g of PHS ͑148°C͒, h r is comparable to the estimated R g in Table I.…”

Section: A Characterization Of Grafting Of Polymers To Substratesmentioning

confidence: 69%

Extraordinary elevation of the glass transition temperature of thin polymer films grafted to silicon oxide substrates

Tate¹,

Fryer

Pasqualini

et al. 2001

The Journal of Chemical Physics

140

127

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We used local thermal analysis and ellipsometry to measure the glass transition temperatures (T g ) of supported thin films of poly͑4-hydroxystyrene͒ ͑PHS͒ and hydroxy terminated polystyrene ͑PS-OH͒. The films were spuncast from solution onto silicon oxide substrates and annealed under vacuum at elevated temperatures to graft the polymer to the substrate. Grafting was verified and characterized in terms of the thickness of and the advancing contact angle of water on the residual layer after solvent extraction. For PHS, each segment of the polymer chain was capable of grafting to the substrate. The thickness of the residual layer increased with increasing annealing temperature. For this polymer the critical thickness below which the T g of the film deviated from the bulk value was nearly 200 nm after annealing at the highest temperature ͑190°C͒; the T g of films 100 nm thick or less were elevated by more than 50°C above the bulk value. For PS-OH films the polymer was only capable of grafting at one chain end, forming a brush layer at the substrate interface. The critical thicknesses for PS-OH films and the T g elevations were substantially higher than for ungrafted PS films, but were not as large as for PHS. The film thickness dependence of T g for PHS and PS-OH were well described as piecewise linear, consistent with a ''dual-mechanism'' model.

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Section: A Characterization Of Grafting Of Polymers To Substratesmentioning

confidence: 69%

Extraordinary elevation of the glass transition temperature of thin polymer films grafted to silicon oxide substrates

Tate¹,

Fryer

Pasqualini

et al. 2001

The Journal of Chemical Physics

140

127

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“…F. Danusso 1 and H. Tanaka 2 refluxed a mixture of PAS, NaOH, H 2 O, and C 2 H 5 OH for 1 h and a mixture of PAS, NaOH, H 2 O and 1,4-dioxane for 36 h, respectively. Deprotection of PAS, 13 as well as PASco-PS, 21 was also carried out at 80 -90°C for 4 h. In order to prevent PAS from undergoing an appreciable gelation reaction between phenolic groups, S. Arichi and coworkers 22 used 2,6-ditert-butylphenol (0.15%) as antioxidant and ran the experiment at room temperature. Hydrazinolysis of PAS, 14 PAS-co-PS, 14,23 crosslinked PAS-co-PS, 3,24 and poly(4-acetoxy-␣-methylstyrene) 4 in 1,4-dioxane at ambient temperature for a different reaction time has been reported.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, G. G. Barclay and coworkers 11,12 have prepared poly(4-hydroxystyrene) (PHS) and poly(4-hydroxystyrene-co-styrene) (PHS-co-PS) with narrow molecular weight distribution (MWD) by "living" free radical polymerization. The resulting materials have been characterized by IR, [1][2][3]11,13,14,[21][22][23][24] NMR and GPC, 11,12,14,23 UV 11,13 elemental analysis, 2 or TGA and DSC. 11 It was also reported that diblock copolymer poly(4-acetoxystyrene-bstyrene) (PAS-b-PS) could be converted to the corresponding amphiphilic material poly(4-hydroxystyrene-b-styrene) (PHS-b-PS) by using a base-catalyzed hydrolysis; however, neither was detailed information given, 15 nor monomodal GPC curve presented.…”

Section: Introductionmentioning

confidence: 99%

Hydrolysis of 4-acetoxystyrene polymers prepared by atom transfer radical polymerization

Chen

Jankova

Kops

et al. 1999

J. Polym. Sci. A Polym. Chem.

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“…This large bh for PHS represents great ability of intramolecular hydrogen bond formation. We reported 12 that the Flory-Huggins entropy and enthalpy parameter for dilution of PHS in various solvents are all negative, and absolute values are considerably large. These results indicate that there exist strong thermodynamic interactions in solution of PHS arising from hydrogen bond formation between polymer and solvent molecules.…”

Section: °Cmentioning

confidence: 99%

“…Molecular weight was determined by intrinsic viscosity measurements using the appropriate Mark-Houwink-Sakurada equation. 12 Methanol of specific quality for fluorescence measurement and 4-ethylphenol were purchased from Nacalai Tesque Inc. 4-Ethylphenol was purified according to the standard procedures.…”

Section: Methodsmentioning

confidence: 99%

Fluorescence and Viscometry Studies of Poly(4-hydroxystyrene) in Solution

Himuro

1993

Polym J

Self Cite

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ABSTRACT:Fluorescence and viscosity of dilute solution of poly(4-hydroxystyrene) (PHS) were measured in methanol in the temperature range 5 to 55°C. The fluorescence spectrum of PHS showed two emission bands at around 308 nm and 356 nm, corresponding to the monomer and the excimer bands, respectively. From the temperature-dependent fluorescence measurements, a plot of the excimer to monomer intensity ratio Idllm versus temperature was obtained, which shows double lines with positive slopes crossing at ca. 35°C. From temperature-dependent viscosity measurements, a plot of the limiting viscosity number ['1] versus temperature was obtained, which shows double lines with negative slopes crossing at ca. 40°C, above which the slope was decreased. These results indicate that there is stronger solvation of solvent molecules to polymer coil at temperatures below ca. 35---40°C, arising from hydrogen bond formation between PHS and methanol molecules.KEY WORDS Poly(4-hydroxystyrene) I 4-Ethylphenol I Excimer I Fluorescence I Polymer Conformation I Polymer Solution I Temperature Dependence I Viscosity I Many vinyl polymers with aromatic chromophores exhibit intramolecular excimer fluorescence in solution. 1 Excimers are excited-state complexes formed by a couple of chromophores placed face to face at a short distance. The formation of an excimer is due to assoc1atwn of two aromatic groups separated by three carbon atoms along the chain, one of which has been electronically excited. 2 It is characteristic for excimer fluorescence to appear in a considerably lower energy region than monomer fluorescence and· to have no mirror image relation to the absorption spectrum. The intramolecular excimer formation for vinyl polymers is governed by both the conformation and configuration of the chains.Excimer formation has been observed in polystyrene 3 -5 and its derivatives such as poly(tX-methylstyrene ), 6 • 7 and poly( 4-methylstyrene),8 but not in such analogous polymers as poly(4-chlorostyrene) and poly(4-bromostyrene ). 9 Jiang et a!. 9 showed that the fluorescence spectrum of poly(4-hydroxystyrene) (PHS) has a vibrational structure and cannot be attributed to the formation of excimer. They insist that the presence of bulky hydroxyl substituents in PHS does not allow parallel arrangement of aromatic rings along with the polymer chain, which is a necessary condition for the excimer formation. However, when Figure 3 in ref 9 is examined, their interpretation does not seem consistent with the view that the monomer fluorescence spectrum is the single mirror image of the absorption spectrum. The fluorescence spectrum in the figure shows the anomalous fluorescence emission band at the longer wavelength than that where the fluorescence emission band corresponding to the mirror image of the absorption spectrum appears. The lower energy band of this fluorescence spectrum 1223

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Dilute solution properties of poly(4-hydroxystyrene)

Cited by 17 publications

References 36 publications

Extraordinary elevation of the glass transition temperature of thin polymer films grafted to silicon oxide substrates

Extraordinary elevation of the glass transition temperature of thin polymer films grafted to silicon oxide substrates

Hydrolysis of 4-acetoxystyrene polymers prepared by atom transfer radical polymerization

Fluorescence and Viscometry Studies of Poly(4-hydroxystyrene) in Solution

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