Investigations of the concentration effect of intramolecular mobility of polystyrene in carbon tetrachloride and chloroform solutions on vibrations of the phenyl group

Abstract

Investigations of relative intensity, line width and depolarizatioli ratio of atactic polystyrene have been perfornicd for the Ranian lines 622 cm-1 (bending) and 1002 cm-1 (stretching). The nieasurements were performed with solutions in carbon tetrachloride and chloroform of different concentrations. The concentration effect obscrved is interpreted in terms of amplitude changes and vibrational correlation time of the investigated vibrational modes with simultaneous change of the chain conformation. Unlcrsurhungen zur Konzentrationsabhangigkeit der intraniolekularen Beweglichkeit von Polystyren in Kohlenstofftetrachlorid und Chloroforna und deren Sinflu/? auf die Schwingungen der PhenylgruppeDie relative Intensitit, Linienbreite und Depolarisation der Ramanlinien 622 cm-' und 1002 cm-' von atalitischem Polystyren wurden gcmessen. Die Untersuchungen erfolgten in Kohlenstofftetrachloridund Chloroformlosungen bci uiilcrschiedlicl~e~i Iionzentrationcn. Die IConzentrationsabhangigkeit der gemessenen Parameter wird im Zusaminenhang mit h i d c r~~r g e n dcr Amplitude und der Korrelationszeiten des Vibralionsanteils der betrachteten Scliwingungen sowie der Anderui:gen der I(ettenhotifor1nation erklart. Ilccnedooanu~ zonyenmpayuonnoii ~~~U C U M O C~U snympu~noaelFyJc~pno~i nodsuwnocnau nonucmupoaao uembcpex-xcnopucmoM yznepoae u xngp,pofi>ppwe u es enumue na ~o n e 6 a n u~ &enuabn3iL zpynnu I/laMepeHbI OTHOCMTeJIbHaR MHTeHCHBHOCTb, IIIMpHHa H RenOJIRpH3aqHR JIMHHfi CneKTpOB KOM6MHaqHOHHOrO paCCe-RHHR 622 CM-' H 1002 CM-l aTaKTHqeCKOI'0 IIOJIMCTHpOJIa. kICCJIeH0BaHHR npOBOAHJIMCb B PaCTBOpaX IIOJlUCTMpOJla B 4eTbIpeXXJIOpMCTOM YI'JIepOAe H XJlOpO$OpMe "pH PaaJIHqHbIX KOH4eHTpaUHHX. KOHqeHTpaqHOHHaR 3aBMCHMOCTb H3MepeHHblX IIapaMeTpOB O~% S I~H R~T C R B CBFIaH C 113MeHeHHRMH aMIIJIHTyAbl M BpeMeH KOppeJIRqMH BHbpaqHOHHOii AOJIH PaCCMaTpABaeMbIX KOXe6aHMfi, a TPKXW C H3MC'lIeHIiRMH KOH@OPMaqMH IJC'nH.

Volumetric concentration effects of polystyrene in carbon tetrachloride and chloroform solutions

“…Results reported in [21] concerning t h e concentration dependence of p of t h e R a m a n lines 622 a n d 1002 cm-' of PS in CCl, a n d CHC1, a n d t h e investigations of t h e Table 1.…”

“…For PS in CCl, the values of cmaX obtained according to EIZNER [7] (cmax = 1.6%) and YAMAKAWA [8] (c,,, = 2.33%) were in quite good agreement. Taking into account t h a t both c,,, values are lower than the lowest concentration used in the investigations of e [21], and the fact that in the whole concentration range of PS in CCl, e rn const. for the lines 622 and 1002 cm-l, it should be concluded that the PS macromolecules in this solvent adopt a certain conformation independent of the concentration, their mean dimensions being the same as a t the 0 point.…”

“…The discussion on the conformational changes of polystyrene (PS) macromolecules with concentratin in CHCI,, given in paper [21], was based on the investigation of the depolarization ratio, e, of the PS Raman lines a t wavenumbers 622 and 1002 cm-l. The increase in e observed in the concentration range of 3.27 c 5 9.20% by wt.…”

“…The above mentioned parameters are measured or calculated for macromolecules in infinitely dilute solutions (c -+ 0). Conclusions reached as to their change when passing t o finite PS concentrations were based upon a detailed analysis of the variations in the depolarization ratio e of the Raman lines[21], and the theoretical calculations of a(c) and cmax according to the relation given by EIZNER[7] and YA-MAKAWA[8].…”