1991 Fiscal Year Final Research Report Summary
Fundamental studies on the ultra drawing mechanism in gel press method
| Project/Area Number |
02452252
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
溶接工学
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| Research Institution | Osaka City University |
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Principal Investigator |
OHTA Toshihiko Osaka City Univ., Sci. of Living, Professor, 生活科学部, 教授 (60213732)
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| Co-Investigator(Kenkyū-buntansha) |
WACHI Takao Osaka City Univ., Sci. of Living, Res. Assc., 生活科学部, 助手 (30073886)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Ultra High Molecular Weight Polyethylene / High Strength / High Modulus / Gel Press Method / Ultra Drawing / Chain Entanglement Density / Gel Like Spherulite |
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| Research Abstract |
The studies on the ultra-drawing mechanism in gel press method, in relation to the entanglement density between polymer chains, were carried out with using of ultra high molecular weight polyethylene. The obtained results are as follows.
1. On the gel press membranes of Al & A2, respectively prepared from the semi-dilute solutions of 1 wt% & 2wt%, the difference of the increasing rates of strengths & moduli by hot-drawing at 100 ﾟC could not be observed. This fact implies that twice the difference on the entanglement density between polymer chains in solution did not reflect to the above difference. It was deduced as this reason that the disentanglement between polymer chains was caused during crystallization from solution, and consequently, the entanglement density of undrawn sample of Al & A2 came in close.
2. On the gel cast membranes of C2, -& QC2, prepared by rapid cooling the semi-dilute solution of 2 wt%, the drawing stress at 100ﾟC and the increasing rates of strength & moduli by hot drawing at IOOﾟC are considerably higher than those of the gel press membranes of Al & A2. It was inferred from this fact that the entanglement densities of the gel cast membranes of C2 & QC2 were considerably higher than those of the gel press membranes of Al & A2, and consequently, the drawing stress became to be easily transferred to all molecules and the fibrilar crystallization by chain extension was accelerated in drawing of the gel cast membranes.
3. The calculated maximum draw ratio of all of the above membranes, based on the assumption that the drawing stress at 100'C increases in proportion to the chain entanglement density, are well coincident with the observed one. It was concluded from this fact that the ultra-drawing mechanism from gel press method to gel cast method can be explained as the deformation of three dimensional net work formed by the chain entanglements.
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Research Products
(8 results)
