A review on the development of liquid chromatography systems for polyolefins

Abstract

Polyolefins are the most widely produced synthetic polymer commodity and are found in countless applications ranging from bottles, packaging films to bullet-proof jackets, etc. Such widely different applications rely on high variability in the physical properties of polyolefins, which is a result of variations in microstructure, chemical composition and molar mass. Though polyolefins contain only carbon (C) and hydrogen (H) atoms, the microstructures of polyolefins are extremely variable, differing in the nature of the monomers (e.g. ethylene versus propylene), the degree of branching, chemical composition in the case of copolymers and finally their molar masses. Production, research and development of polyolefins require the analysis of polyolefin samples in terms of all these parameters. Development of efficient and robust analytical techniques based on the interactive LC is reviewed. The needed computational/theoretical studies to understand the retention mechanism in the newly developed chromatography systems are discussed.

Recent Advances in High-Temperature Fractionation of Polyolefins

“…Full or partial adsorption of PE and isotactic PP on different column packings were found; see a summary in Table 4 [143]. The pores of some zeolites, e.g., SH-300, correspond to the diameter of PE in its linear conformation but are smaller than the corresponding diameter of PP.…”

Separation of bimodal high density polyethylene using multidimensional high temperature liquid chromatography

“…4). 1-decanol was chosen as adsorption promoting liquid as the retention of HDPE is larger in comparison with other solvents like 2-octanol and 2-ethyl-1-hexanol and furthermore dissolution was good in 1-decanol [59][60][61][62][63][64][65][66][67][68][69][70][71][72][73]81] and TCB, which is the solvent commonly used in SEC of polyolefins, was applied as desorption promoting liquid. Fig.…”

Interactions of complex polymers with nanoporous substrate

“…Several excellent reviews, mostly focusing on experimental results and procedures, have been written on this subject. [4][5][6][7][8][9][10] Here we will focus on the microscopic picture of how a complex polymer interacts with nanoporous materials in these elution modes. It will become clear that there is an interesting fundamental question encountered in understanding the elution of complex polymers in polymer liquid chromatography, namely, the existence of a Critical Adsorption Point (CAP) of a polymer on the column substrate.…”