1990 Fiscal Year Final Research Report Summary
Comformations of Low Molecular Weight Polymers in Solution
| Project/Area Number |
01550691
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
高分子物性
|
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
MUROGA Yoshio Nagoya University Assistant Professor Fac. of Eng., 工学部, 助手 (00115643)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Low Molecular Weight Polymers / Conformations of Polymer Chains / Local Structures of Polymer Chains / Solution properties of Polymer Chains / Small Angle X-ray Scattering / Poly(sodium acrylate) / Polyethylene / Poly(methyl methacrylate) |
|---|
| Research Abstract |
Up to date, numerous investigations have been carried out on the conformational analysis of polymer chains in solution. However, most of them were directed to that of higher molecular weight samples. The purpose of the present is the solution of small angle X-ray scattering, SAXS.
Some derived conclusions are as follows:
(1) The persistence lenghr of a chain for polystyrene of M_n (number averaged molecular weight)=4.0x10^3 and poly (sodium acrlylate) of M_n=2.0x10^3 are evaluated 7 to 11 LAMBDA, comparable with those for the higher molecular weight polymers. It is conceivable that the conformation of these two polymers could be represented by the same chain model such as a a wormlike chain model, irrespectively of the molecular weight.
(2) The conformations of isotactic and syndiotactic poly (methy methacrylate), iso-PMMA and syn-PMMA, were studied on the basis of the scattering functions. Iso-PMMA with the molecular weight less than 1.0x10^4 behaves as a wormlike chain independently of the molecular weight. Incontrast sy n-PMMA, the chain conformation of lower molecular weight cannot be represented by a wormlike chain model, while the higher molecular weight one behaves in the same way as iso-PMMA. This seems to reflect the difference in the local conformations between iso-and syn-PMMA.
(3) The chain conformations of low molecular weight polyethylenes in solution were studied on the basis of the radius of gyration of the chains. While polyethylene with the molecular weight larger than 1.0x10^4 behaves as a random coil, its behavior deviates from a random coil to a rod, as the molecular weight decreases.
|
