Comprehensive branching analysis of polyethylene by combined fractionation and thermal analysis. Issue 2 (14th March 2018)

• Record Type: Journal Article
• Authors: Ndiripo, Anthony; Eselem Bungu, Paul Severin; Pasch, Harald
• Is Part Of: Polymer international. Volume 68:Issue 2(2019)
• Page Start: 206
• Page End: 217
• Publication Date: 2018-03-14
• Subjects: polyethylene -- branching -- temperature rising elution fractionation -- crystallization fractionation -- differential scanning calorimetry -- size exclusion chromatography; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.7
• DOI: 10.1002/pi.5547
• Languages: English
• ISSNs: 0959-8103

Abstract

Abstract: Linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) differ significantly in their branching types and branching distributions. For a comprehensive analysis, preparative temperature rising elution fractionation and/or preparative molar mass fractionation are used to fractionate typical LLDPE and LDPE bulk resins into narrowly distributed fractions. The chain structures of the bulk resins and their fractions are further analysed using SEC, crystallization analysis fractionation, DSC and high‐temperature HPLC to provide detailed information on short chain branching in LLDPE and long chain branching in LDPE. For LDPE it is shown that the multiple fractionation approach is a powerful source of sample libraries that may have similar molar masses and different branching structures or alternatively similar branching but different molar masses. The analysis of these library samples by thermal analysis provides a much deeper insight into the molecular heterogeneity of the samples compared to bulk sample analysis. © 2018 Society of Chemical Industry Abstract : Linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) differ significantly in their branching distributions. For comprehensive analysis, a multidimensional analytical approach is used that is based on the combination of preparative fractionation and advanced analytical methods.