Characterizing long-chain Branching in Polyethylene with Extensional Rheology


Haake MARS Rheometer 와 SER Tool Option을 사용한 폴리에틸렌 필름

시편의 Long-chain branching 관련 연구 자료.



The material was deformed with the SER (see Fig. 2) during

the stretching tests. To do this the sample has to be secured

onto the drums of the SER with included clamps. The test

itself was then conducted in RheoWin via the routine that

can be seen in Fig. 3. After the sample has reached 150 °C

and the temperature was held constant for 5 minutes the

sample was pre-stretched (153 Pa for LDPE) for 10

seconds to counteract the gravitation induced sagging as

well as ensure that the gearbox is in a state that the test

can begin right away. Afterwards the drums rotate at a

given strain rate until the deflection angle reaches a value

of 230° (afterwards the clamps would touch). The experiments

were conducted at strain rates of 0.01 s-1, 0.05 s-1,

0.1 s-1, 0.5 s-1, 1.0 s-1 and 5.0 s-1, however the highest strain

rate was not used for the HDPE as no strain hardening

would have been monitored there.