Engineered PP impact copolymers in a single reactor as efficient method for determining their structure and properties

Impact polypropylene (PP) copolymers (IPCs) are important materials for many commercial applications. These usually synthetized through different methods involving two consecutive reactions in the same phase or phases. Here, a laboratory-scale synthesis method based on sequential liquid- and gas-phase two-step process single reactor is developed. Propylene homopolymers IPCs were synthesized with varying amounts of comonomers hydrogen. The IPC obtained fully characterized via analytical temperature rising elution fractionation (TREF), differential scanning calorimetry (DSC), 13C nuclear magnetic resonance (13C NMR), gel permeation chromatography an infrared detector (GPC-IR5), Charpy impact, electron microscopy (SEM), cross-fractionation (CFC). addition only ethylene to second step absence hydrogen led creation ethylene-propylene (EP) copolymer similar impact strength that propylene homopolymer. first dramatically shortened length PP chains inhibited catalytic active centers EP synthesis. This material exhibited very low molecular weight, incorporation, rubbery phases irregularly distributed along isotactic (iPP) matrix, resulting formation poor properties. without 50/50 (v/v) mixture propylene/ethylene monomers enhance facilitating adequate homogeneous heterogeneous distribution high increment amorphous ethylene-propylene-rubber (EPR) domains, which remarkably improves Additionally, criterion ratio between EEE EPE + PEP triads ranging 1 2 was also established predict resistance any heterophasic PP. Fractionation optimal sample provided detailed understanding about microstructure this study weight composition fractions GPC-IR, TREF, DSC measurements. Finally, liquid–gas-phase compared, by means SEM CFC measurements, using liquid–liquid-phase polymerization, results showed range as well molar mass molecules correlated their mechanical behavior. proves crystalline families composed high-molecular-weight can act compatibilizing agent iPP matrix elastomeric phase, allowing one improve IPC, more so than gas–gas liquid–liquid indicate resins efficient experimental fundamental research IPCs.