Design of high impact thermal plastic polymer composites with balanced toughness and rigidity: Toughening with core-shell rubber modifier

Copolymer Distribution in Core–Shell Rubber Particles in High-Impact Polypropylene Investigated by Atomic Force Microscopy–Infrared

“…This structure is thermodynamically unstable because the PP in the core is expected to migrate and merge with the PP matrix whenever possible in order to reduce the interfacial energy. This, together with the lack of a suitable technique for in situ structure and composition analysis until recently, probably is the main reason why this kind of structure is rarely reported. , However, the most recent theoretical work by Jiang et al indicates that when everything else is equal, HIPP with a crystalline PP core in the rubber particle is superior to the one with a crystalline PE core in rigidity of the composite and may be the direction leading to the next generation HIPP . Therefore, exploring this kind of unusual structure and understanding its formation mechanism are important.…”

“…For multiphasic composite systems, such as HIPP, the morphological structure is also crucial to the mechanical properties. ,, Our in situ composition analysis by AFM–IR, as discussed above, has revealed that the rubber particles in HIPP-1 contain crystalline PE cores, whereas the ones in HIPP-2 contain crystalline PP cores. Jiang et al have recently established a theoretical model on toughening with the core–shell rubber modifier, which predicts that core–shell rubber particles result in less rigidity loss of the toughened composite than the one-phase impact modifier, and the effect is more pronounced when the modulus of the core is higher . More specifically, for HIPPs, core–shell rubber particles with PP cores are beneficial to the rigidity than the ones with PE cores because the modulus of PP is about 1.6 times that of PE .…”

“…30,31 However, the most recent theoretical work by Jiang et al indicates that when everything else is equal, HIPP with a crystalline PP core in the rubber particle is superior to the one with a crystalline PE core in rigidity of the composite and may be the direction leading to the next generation HIPP. 44 Therefore, exploring this kind of unusual structure and understanding its formation mechanism are important. We attribute the presence of a large portion of PP in the core in HIPP-2 mainly to the more balanced structure of the EbP, which allows it to phase-separate in a significant amount with the EsP first and compatibilize some PP trapped in the process to form the core.…”

“…Jiang et al have recently established a theoretical model on toughening with the core−shell rubber modifier, which predicts that core−shell rubber particles result in less rigidity loss of the toughened composite than the one-phase impact modifier, and the effect is more pronounced when the modulus of the core is higher. 44 More specifically, for HIPPs, core−shell rubber particles with PP cores are beneficial to the rigidity than the ones with PE cores because the modulus of PP is about 1.6 times that of PE. 44 Our result is in line with this theoretical prediction and provides first experimental evidence that the unusual morphological structure of PP cores in the rubber particles in HIPP can be formed with a suitable copolymer structure and composition, which in turn contributes to the better rigidity and toughness of the PP impact copolymer.…”

“…44 More specifically, for HIPPs, core−shell rubber particles with PP cores are beneficial to the rigidity than the ones with PE cores because the modulus of PP is about 1.6 times that of PE. 44 Our result is in line with this theoretical prediction and provides first experimental evidence that the unusual morphological structure of PP cores in the rubber particles in HIPP can be formed with a suitable copolymer structure and composition, which in turn contributes to the better rigidity and toughness of the PP impact copolymer.…”