Molecular Weight Distribution of Polystyrene Obtained by Employing n-Amyllithium Catalyst

Synthesis of high molecular weight polyethylene using FI catalyst

A FI Zr-based catalyst of bis[N-(3,5-dicumylsalicylidene)-2′,6′­diisopropylanilinato]zirconium(IV) dichloride was prepared and used for polymerization of ethylene. The effects of reaction conditions on the polymerization were examined in detail. The increase in ethylene pressure and rise in polymerization temperature up to 35 oC were favorable for catalyst/MAO to raise the catalytic activity as...

Preparation of Ultra High Molecular Weight Polyethylene Using Ziegler-Natta Catalyst System: Optimization of Parameters by Response Surface Methodology

High molecular weight polystyrene as very sensitive electron beam resist

0167-9317/$ see front matter 2012 Elsevier B.V. A http://dx.doi.org/10.1016/j.mee.2012.07.005 ⇑ Corresponding author. Tel.: +1 519 729 3582. E-mail addresses: [email protected], j24 (J. Zhang). Previously we demonstrated ultra-dense patterning using 2 kg/mol polystyrene negative electron beam resist that has low sensitivity [16]. To drastically improve its sensitivity, here we studied the expos...

Absolute Molecular Orientational Distribution of the Polystyrene Surface

Vibrationally resonant sum frequency generation (VR-SFG) has been used to study the absolute molecular orientational distribution of the pendant phenyl groups at the free surface of polystyrene (PS) thin films on oxidized Si substrates. Characterization of the dependence of the VR-SFG on film thickness allows unique identification of the origin of the signal, e.g., free surface, bulk, or buried...

Rheological Method for Determining Molecular Weight and Molecular Weight Distribution