POLY 135 |
| The effect of flow on crystallization on two low-molecular weight polyethylene base resins is studied using short-term shearing for future use in bimodal blends containing hydrogenated polybutadienes of complex architecture. Base50 is polyethylene-co-hexene (Mw = 50 kg/mol, Mw/Mn = 1.97) with 5 mol % hexene. Base45 is ethylene-co-octene copolymer (Mw = 45 kg/mol, Mw/Mn = 2.3) with 5 mol % octene and approximately half the viscosity of Base50. Samples with a controlled thermal history are subjected to shear stresses on the order of 0.1 MPa and structure development is monitored by in-situ turbidity, birefringence and SALS measurements. Neither resin exhibited enhanced crystallization kinetics or oriented morphology under shear. Base50 demonstrated oriented precursor formation under high shear, while Base45 did not. Base45 was further tested with a small amount of linear HDPE in order to demonstrate that its comonomer content did not fully inhibit the formation of an oriented morphology. |
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General Papers: Functional Materials
6:00 PM-8:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Polymer Chemistry |