The chemical structure of the amorphous phase of propylene–ethylene random copolymers in relation to their stress–strain properties

Agarwal, Vipin; Erp, Tim B. van; Balzano, Luigi; Gahleitner, Markus; Parkinson, Matthew; Govaert, Leon Le; Litvinov, V. M.; Kentgens, A.P.M.

doi:10.1016/j.polymer.2013.12.051

Cited by 24 publications

(18 citation statements)

References 56 publications

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“…In the CPMAS spectra obtained for polypropylene homopolymer (Figure A) there is a marked development of additional signals to the methylene and methine carbons at 46.5 and 28.5 ppm, respectively with increasing temperature. These resonances were also detected in the 60 °C TREF fractions of samples with higher total ethylene contents (refer to Figure D) as well as in the random copolymers analyzed by Agarwal et al . and were assigned to methylene and methine carbons in amorphous polypropylene.…”

Section: Resultsmentioning

confidence: 66%

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The Use of Solid‐State NMR to Investigate the Development of Segmental Mobility in Commercial Heterophasic Ethylene Propylene Copolymers (HEPCs)

Botha

Sinha

Duveskog

et al. 2015

Macro Reaction Engineering

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The effect increasing ethylene incorporation on the development of commercial heterophasic ethylene propylene copolymers (HEPCs) was previously evaluated in terms of particle morphology, chemical composition, crystallinity, and microstructure. These polymers were obtained from a commercial gas-phase process and enabled the visualization of the early development of the copolymer phase while including the effects of large-scale production processes on the resulting polymer properties. Based on the ethylene-dependent changes observed for the HEPCs as well as some semi-crystalline TREF fractions, further variable temperature solid-state 13 C NMR experiments were done to observe temperature-dependent shifts in localised mobility within the bulk samples during a heating/melting profile. From these experiments, the development of amorphous polypropylene signals was observed with increasing temperature, which could indirectly be related to the introduction of ethylene defects. It was also observed that polypropylene components with high rigidity remained at high temperatures for the HEPCs but not for the homopolymer. T 1 r experiments were used to differentiate between changes in crystalline and non-crystalline phases based on ethylene incorporation as well as during melting. In this publication, the observations from the perspective of the solid-state analyses are outlined and placed in the context of the evolution of microscopic, chemical, microstructural, and mechanical properties.

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Section: Resultsmentioning

confidence: 66%

“…Agarwal et al . investigated the chain dynamics of the amorphous phase of a series of commercial random ethylene–propylene copolymers and a single HEPC using solid‐state 1 H NMR experiments . Lovisi et al .…”

Section: Introductionmentioning

confidence: 99%

The Use of Solid‐State NMR to Investigate the Development of Segmental Mobility in Commercial Heterophasic Ethylene Propylene Copolymers (HEPCs)

Botha

Sinha

Duveskog

et al. 2015

Macro Reaction Engineering

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“…It shows that the r E ′ · r P ′ value of alloy‐1 is 21.4, almost twice that of alloy‐2, indicating higher blockiness of the s‐EP chains formed in the presence of CHMDMS. In addition, the proportion of alternating triads PEP in alloy‐1 is lower than that in alloy‐2, which also shows a weaker blockiness in alloy‐2 . The average sequence length of the ethylene unit ( n E ′) in these two alloys is almost the same, however, the average sequence length of the propylene unit ( n P ′) of alloy‐1 is larger than that of alloy‐2.…”

Section: Resultsmentioning

confidence: 94%

Preparation and characterization of high MFR polypropylene and polypropylene/poly(ethylene‐co‐propylene) in‐reactor alloys

Zhang

Fan

et al. 2015

J of Applied Polymer Sci

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In this work, high melt flow rate (MFR) polypropylene (HF-PP) and polypropylene/poly(ethylene-co-propylene) inreactor alloys (HF-PP/EPR) with MFR % 30 g/10 min were synthesized by spherical MgCl 2 -supported Ziegler-Natta catalyst with cyclohexylmethyldimethoxysilane (CHMDMS) or dicyclopentyldimethoxysilane (DCPDMS) as external donor (De). The effects of De on polymerization activity, chain structure, mechanical properties, and phase morphology of HF-PP and HF-PP/EPR were studied. Adding CHMDMS caused more sensitive change of the polymers MFR with H 2 than DCPDMS, and produced PP/EPR alloys containing more random ethylene-propylene copolymer (r-EP) and segmented ethylene-propylene copolymer (s-EP). CHMDMS also caused formation of s-EP with higher level of blockiness than DCPDMS. HF-PP/EPR alloy prepared in the presence of DCPDMS exhibited higher flexural properties but lower impact strength than that prepared with CHMDMS. Toughening efficiency of the rubber phase was nearly the same in the alloys prepared using CHMDMS or DCPDMS as De, but stiffness of the alloy can be improved by using DCPDMS.

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“…Impact poly(propylene) copolymers (IPCs) have been used extensively for many applications in the automotive, packaging, and electrical appliances industries since these materials have superior properties over traditional poly(propylene) (PP) materials due to their multiphase morphology where ethylene–propylene rubber particles are incorporated in an isotactic poly(propylene) ( it ‐PP) matrix . As such, IPC materials have increased impact strengths and tensile‐fracture properties as compared to it ‐PP.…”

Section: Introductionmentioning

confidence: 99%

Exploring the Compositional Heterogeneity of Vis‐Broken Impact Poly(propylene) Copolymers by Advanced Fractionation Methods

Phiri

Pasch

2016

Macro Chemistry & Physics

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Vis‐breaking or rheology control is an important technical process to improve the processability of impact poly(propylene) copolymers (IPCs). In the vis‐breaking process the molar mass and its dispersity are reduced and the crystallinity changes and polar carbonyl functionalities are introduced due to the reaction of the polymer with peroxide. Although the fundamental principles of vis‐breaking are well understood, not much research has been devoted to the investigation of the molecular changes brought about by the vis‐breaking process. In the present study, the effect of vis‐breaking on the molecular parameters of IPCs is elucidated using advanced fractionation methods. After the analysis of the bulk sample properties, the samples are fractionated using preparative temperature rising elution fractionation and the fractions are analyzed by Fourier transform infrared spectroscopy, differential scanning calorimetry, crystallization analysis fractionation, and high temperature high performance liquid chromatography techniques. For the first time, an effective multidimensional analytical approach is established to study compositional heterogeneities in vis‐broken IPC materials.

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The chemical structure of the amorphous phase of propylene–ethylene random copolymers in relation to their stress–strain properties

Cited by 24 publications

References 56 publications

The Use of Solid‐State NMR to Investigate the Development of Segmental Mobility in Commercial Heterophasic Ethylene Propylene Copolymers (HEPCs)

The Use of Solid‐State NMR to Investigate the Development of Segmental Mobility in Commercial Heterophasic Ethylene Propylene Copolymers (HEPCs)

Preparation and characterization of high MFR polypropylene and polypropylene/poly(ethylene‐co‐propylene) in‐reactor alloys

Exploring the Compositional Heterogeneity of Vis‐Broken Impact Poly(propylene) Copolymers by Advanced Fractionation Methods

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