Long-chain branching (LCB) is a very important polymer architectural attribute for polyethylene resins and has been extensively studied since the creation of the first polyethylene resin made using peroxide catalyst under high temperature and high pressure (i.e. LDPE). The presence of LCB not only affects polymer processability but also polymer mechanical properties. Depending on applications, the right amount, type, and distribution of LCB are necessary in order to produce products that meet the desired processability and end-use properties. In this talk, we will present LCB characterization of LDPE, and polyethylene resins made using the Phillips catalyst, Ziegler-Natta catalyst and metallocene catalyst under low pressure and low temperature using size-exclusion chromatography (SEC, also known as gel-permeation chromatography, GPC) hyphenated with multi-angle light scattering (MALS) (i.e. SEC-MALS) in conjunction with other spectroscopic, rheological and fractionation techniques. Some of these results will be compared to those obtained via asymmetrical flow field-flow fractionation (AF4) coupled with MALS (i.e. AF4-MALS). Polymer architectural characteristics of these four types of PE resins will also be discussed in this presentation.

Not all long chain branching in polyethylene is created equal

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.