Thermodynamic and kinetic aspects of cocrystallization and phase segregation phenomena of polyethylene blends between the D and H species as viewed from DSC, FTIR and synchrotron X‐ray scattering

Abstract

Cocrystallization and phase segregation phenomena of polyethylene (PE) blends between fully deuterated high-density PE (DHDPE) and hydrogeneous PE with various degrees of ethyl branching have been investigated on the basis of DSC, FTIR, synchrotron X-ray scattering, and neutron scattering measurements. When the blend between DHDPE and linearlow-density PE [LLDPE(2) with 17 ethyl branches/1000 carbons is cooled slowly from the molten state, it exhibits an almost perfect cocrystallization o f the D and H species in the same crystalline lamellae. For the blends of DHDPE with LLDPE(3) with higher branching content (41 branches/lOOOC) or with HDPE without branching, the cocrystallization and/or phase segregation phenomena have been observed to vary systematically depending on the D/H content and on the crystallization condition.The spatial arrangement of the D and H stems in the lamella, the aggregation state of the lamellae in the spherulites, etc. were investigated for these blend samples. Differences in crystallization behavior between the meltcooled sample and the solution-grown sample were clarified on the basis of DSC, FTIR, and X-ray diffraction data. The time-resolved FTIR and small-angle X-ray scattering measurements have revealed that the crystallization rate is one of the important factors to govern the cocrystallization and phase segregation phenomena in addition to the thermodynamic stability of the blends.

X-ray diffraction of polymer under load at cryogenic temperature

“…The calculated E t values for the ͑200͒ plane of polyethylene were 10.2 GPa ͑4 K͒, 19 10.5 GPa ͑0 K͒, 20 and 10.9 GPa ͑0 K͒. 21 The calculated values agree with the experimentally determined moduli at 18 K within the experimental error.…”

X-ray diffraction of polymer under load at cryogenic temperature

“…The calculated E t values for the ͑200͒ plane of polyethylene were 10.2 GPa ͑4 K͒, 19 10.5 GPa ͑0 K͒, 20 and 10.9 GPa ͑0 K͒. 21 The calculated values agree with the experimentally determined moduli at 18 K within the experimental error.…”

Ethylene polymerization and copolymerization reactions with Ti( O R ) 4 – Al 2 ( C 2 H 5 )

“…Crystallization from dilute solution produces thick crystallites (lamellae) and very short tight folds, which form small amorphous regions. When PE crystallizes from the melt, the lamellae are thinner and the folds are larger 25–32 . In the present research, nascent polymers were formed at 50 °C in toluene/polymer slurry.…”

“…When PE crystallizes from the melt, the lamellae are thinner and the folds are larger. [25][26][27][28][29][30][31][32] In the present research, nascent polymers were formed at 50°C in toluene/polymer slurry. PE chains are very flexible (the rotation time for the CH 2 -CH 2 bond is merely ca 40 ps 33 ) and the chain crystallization process during the polymerization reactions is similar to crystallization from solution; it leads to the formation of thick regular lamellae with a high melting point and a high crystallinity degree.…”

Metropolis Monte Carlo Simulation of Two-Dimensional Small-Angle X-ray Scattering Patterns of Oriented Polymer Materials

“…The ratio of the total area of particles to the whole area of the cell is a measure of the degree of crystallinity, which is 31% ( N = 4800) to 69% (for N = 10,000). The actual SAXS data was collected for the LLDPE sample with 17 ethyl branches/1000 carbon atoms whose degree of crystallinity was approximately 50% (by X-ray diffraction data and DSC data) . The models of N = 6400 (crystallinity of 44%) and 8000 (55%) may correspond to the actual sample.…”

X-ray diffraction of polymer under load at cryogenic temperature

“…The calculated E t values for the ͑200͒ plane of polyethylene were 10.2 GPa ͑4 K͒, 19 10.5 GPa ͑0 K͒, 20 and 10.9 GPa ͑0 K͒. 21 The calculated values agree with the experimentally determined moduli at 18 K within the experimental error.…”

Ethylene polymerization and copolymerization reactions with Ti( O R ) 4 – Al 2 ( C 2 H 5 )

“…Crystallization from dilute solution produces thick crystallites (lamellae) and very short tight folds, which form small amorphous regions. When PE crystallizes from the melt, the lamellae are thinner and the folds are larger 25–32 . In the present research, nascent polymers were formed at 50 °C in toluene/polymer slurry.…”

“…When PE crystallizes from the melt, the lamellae are thinner and the folds are larger. [25][26][27][28][29][30][31][32] In the present research, nascent polymers were formed at 50°C in toluene/polymer slurry. PE chains are very flexible (the rotation time for the CH 2 -CH 2 bond is merely ca 40 ps 33 ) and the chain crystallization process during the polymerization reactions is similar to crystallization from solution; it leads to the formation of thick regular lamellae with a high melting point and a high crystallinity degree.…”

Metropolis Monte Carlo Simulation of Two-Dimensional Small-Angle X-ray Scattering Patterns of Oriented Polymer Materials

“…The ratio of the total area of particles to the whole area of the cell is a measure of the degree of crystallinity, which is 31% ( N = 4800) to 69% (for N = 10,000). The actual SAXS data was collected for the LLDPE sample with 17 ethyl branches/1000 carbon atoms whose degree of crystallinity was approximately 50% (by X-ray diffraction data and DSC data) . The models of N = 6400 (crystallinity of 44%) and 8000 (55%) may correspond to the actual sample.…”

X-ray diffraction of polymer under load at cryogenic temperature

“…The calculated E t values for the ͑200͒ plane of polyethylene were 10.2 GPa ͑4 K͒, 19 10.5 GPa ͑0 K͒, 20 and 10.9 GPa ͑0 K͒. 21 The calculated values agree with the experimentally determined moduli at 18 K within the experimental error.…”

Ethylene polymerization and copolymerization reactions with Ti( O R ) 4 – Al 2 ( C 2 H 5 )

“…Crystallization from dilute solution produces thick crystallites (lamellae) and very short tight folds, which form small amorphous regions. When PE crystallizes from the melt, the lamellae are thinner and the folds are larger 25–32 . In the present research, nascent polymers were formed at 50 °C in toluene/polymer slurry.…”

“…When PE crystallizes from the melt, the lamellae are thinner and the folds are larger. [25][26][27][28][29][30][31][32] In the present research, nascent polymers were formed at 50°C in toluene/polymer slurry. PE chains are very flexible (the rotation time for the CH 2 -CH 2 bond is merely ca 40 ps 33 ) and the chain crystallization process during the polymerization reactions is similar to crystallization from solution; it leads to the formation of thick regular lamellae with a high melting point and a high crystallinity degree.…”

Metropolis Monte Carlo Simulation of Two-Dimensional Small-Angle X-ray Scattering Patterns of Oriented Polymer Materials

“…The ratio of the total area of particles to the whole area of the cell is a measure of the degree of crystallinity, which is 31% ( N = 4800) to 69% (for N = 10,000). The actual SAXS data was collected for the LLDPE sample with 17 ethyl branches/1000 carbon atoms whose degree of crystallinity was approximately 50% (by X-ray diffraction data and DSC data) . The models of N = 6400 (crystallinity of 44%) and 8000 (55%) may correspond to the actual sample.…”