서지주요정보
동적 광산란과 점도 측정에 의한 선형 폴리스티렌 용액의 분자 엉킴 농도 결정 = Determination of entanglement concentration in linear polystyrene solution by dynamic light scattering and viscosity measurement
서명 / 저자 동적 광산란과 점도 측정에 의한 선형 폴리스티렌 용액의 분자 엉킴 농도 결정 = Determination of entanglement concentration in linear polystyrene solution by dynamic light scattering and viscosity measurement / 권순길.
저자명 권순길 ; Kwon, Soon-Gill
발행사항 [서울 : 한국과학기술원, 1988].
Online Access 원문보기 원문인쇄

소장정보

등록번호

4105045

소장위치/청구기호

학술문화관(문화관) 보존서고

MCE 8804

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

Diffusion coefficients and viscosities of linear atactic polystyrene (PS) with different molecular weight ($M_w = 5.75×10^5$, $9.0×10^5$, and $1.61×10^6$) are measured to examine the dynamic and mechanical properties of linear flexible polymers in a tetrahydrofuran (THF). The diffusion coefficients are measured by using the apparatus of a dynamic light scattering (DLS), and the viscosities by using a Haake viscometer for high shear rates and capillary viscometer for low shear rate. It is verified that the THF is a good solvent for the PS because of the satisfaction of Huggins coefficient (0.32-0.37). Molecular weight distribution (MWD) analyzed by the histogram method from the diffusion coefficients is nearly consistent with gel permeation chromatography (GPC) data, and those results show that the PS samples have Wesslau distribution as well known. In infinite dilute solutions, the hydrodynamic radius ($R_H$) is equal to the radius of gyration ($R_G$) according to the Stokes-Einstein hard sphere model, but the DLS data show that the $R_H$ is much smaller than the $R_G(R_G/R_H=1.7-1.9)$. De Gennes suggested that the transition from the motion of one isolated polymer chain to that of blobs might be occurred at the overlap concentration[$C^*$]. However, the transitional concentration obtained from the DLS experiment, [$C^D$], appears over the $C^*$. In other hand, the transitional concentration obtained from the zero-shear viscosity ($η_o$) measurement, [$C^V$], is consistent with the entanglement concentration[$C^{**}$] predicted by Klein. Over the transition concentration, the zero-shear viscosity is shown as $η_0 ∝ C^{4.86}$. As a result, it is concluded that the molecular model proposed by Klein, which incorporates the constraint release on a reptating chain, is more plausible than that by de Gennes.

서지기타정보

서지기타정보
청구기호 {MCE 8804
형태사항 vii, 59 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Soon-Gill Kwon
지도교수의 한글표기 : 정인제
지도교수의 영문표기 : In-Jae Chung
학위논문 학위논문(석사) - 한국과학기술원 : 화학공학과,
서지주기 참고문헌 : p. 56-59
주제 Matter --Properties.
고분자 용액. --과학기술용어시소러스
기계적 성질. --과학기술용어시소러스
Polymer solutions.
QR CODE qr code