Polyethylene

Functional Polyethylenes by Organometallic-Mediated Radical Polymerization of Biobased Carbonates

“…Moreover, the copolymers synthesized at 50 and 500 bar presented a semicrystalline behavior as a result of their high ethylene content, >78 mol % (entries 4 and 5, Tables and ; Figure S15). The melting temperatures ( T m ) of the copolymers with high polar monomer content were strongly reduced, down to 46 °C (entry 4, Tables and ), compared with regular PE ( T m = 110–130 °C) and were observed to be broad, that is, over a large range of temperatures (Figure S15), which is analogous to previously reported ethylene copolymers containing polar comonomers. ,,, As a result of this broad T m , a clear identification of a T g was not possible for P­( E - co - M2 ) synthesized at 500 bar (Figure S15b). It should be noted that the copolymers do not have the same M n , which strongly impacts their crystallinity, as observed for P­( E - co - M1 ) synthesized at 50 and 500 bar, which contained the same amount of polar monomer (16 mol %) but had different crystallinities (4.5 and 9.5%, respectively; entries 4 and 5, Table ).…”

Functional Polyethylenes by Organometallic-Mediated Radical Polymerization of Biobased Carbonates

“…Moreover, the copolymers synthesized at 50 and 500 bar presented a semicrystalline behavior as a result of their high ethylene content, >78 mol % (entries 4 and 5, Tables and ; Figure S15). The melting temperatures ( T m ) of the copolymers with high polar monomer content were strongly reduced, down to 46 °C (entry 4, Tables and ), compared with regular PE ( T m = 110–130 °C) and were observed to be broad, that is, over a large range of temperatures (Figure S15), which is analogous to previously reported ethylene copolymers containing polar comonomers. ,,, As a result of this broad T m , a clear identification of a T g was not possible for P­( E - co - M2 ) synthesized at 500 bar (Figure S15b). It should be noted that the copolymers do not have the same M n , which strongly impacts their crystallinity, as observed for P­( E - co - M1 ) synthesized at 50 and 500 bar, which contained the same amount of polar monomer (16 mol %) but had different crystallinities (4.5 and 9.5%, respectively; entries 4 and 5, Table ).…”

Aliphatic Polyester Materials from Renewable 2,3-Butanediol

“…The reduced crystallinity, resulting from the presence of methyl branches, can account for these differences. The observed properties are in the range of properties found for LDPE ( E t = 240 MPa, σ y = 12 MPa, ε tb = 653%) …”

Polyethylene materials with in-chain ketones from nonalternating catalytic copolymerization

“…Indeed, tensile tests on injection molded test bars showed a ductile behavior comparable to commercial HDPE (Fig. 3D): modulus of elasticity E = 1062 ± 53 MPa and tensile strength σ y = 26.7 ± 0.2 MPa, compared with literature values of E = 900 MPa and σ y = 27 MPa for HDPE, and E = 240 MPa and σ y = 12 MPa for LDPE ( 31 ). No evidence for undesirable cross-linking that could hamper melt processing was observed; cross-linking promoted by keto motifs has previously been an issue in the thermoplastic processing of commercial polyketone resins ( 32 ).…”

Functional Polyethylenes by Organometallic-Mediated Radical Polymerization of Biobased Carbonates

“…Moreover, the copolymers synthesized at 50 and 500 bar presented a semicrystalline behavior as a result of their high ethylene content, >78 mol % (entries 4 and 5, Tables and ; Figure S15). The melting temperatures ( T m ) of the copolymers with high polar monomer content were strongly reduced, down to 46 °C (entry 4, Tables and ), compared with regular PE ( T m = 110–130 °C) and were observed to be broad, that is, over a large range of temperatures (Figure S15), which is analogous to previously reported ethylene copolymers containing polar comonomers. ,,, As a result of this broad T m , a clear identification of a T g was not possible for P­( E - co - M2 ) synthesized at 500 bar (Figure S15b). It should be noted that the copolymers do not have the same M n , which strongly impacts their crystallinity, as observed for P­( E - co - M1 ) synthesized at 50 and 500 bar, which contained the same amount of polar monomer (16 mol %) but had different crystallinities (4.5 and 9.5%, respectively; entries 4 and 5, Table ).…”

Aliphatic Polyester Materials from Renewable 2,3-Butanediol

“…The reduced crystallinity, resulting from the presence of methyl branches, can account for these differences. The observed properties are in the range of properties found for LDPE ( E t = 240 MPa, σ y = 12 MPa, ε tb = 653%) …”

Polyethylene materials with in-chain ketones from nonalternating catalytic copolymerization

“…Indeed, tensile tests on injection molded test bars showed a ductile behavior comparable to commercial HDPE (Fig. 3D): modulus of elasticity E = 1062 ± 53 MPa and tensile strength σ y = 26.7 ± 0.2 MPa, compared with literature values of E = 900 MPa and σ y = 27 MPa for HDPE, and E = 240 MPa and σ y = 12 MPa for LDPE ( 31 ). No evidence for undesirable cross-linking that could hamper melt processing was observed; cross-linking promoted by keto motifs has previously been an issue in the thermoplastic processing of commercial polyketone resins ( 32 ).…”

Functional Polyethylenes by Organometallic-Mediated Radical Polymerization of Biobased Carbonates

“…Moreover, the copolymers synthesized at 50 and 500 bar presented a semicrystalline behavior as a result of their high ethylene content, >78 mol % (entries 4 and 5, Tables and ; Figure S15). The melting temperatures ( T m ) of the copolymers with high polar monomer content were strongly reduced, down to 46 °C (entry 4, Tables and ), compared with regular PE ( T m = 110–130 °C) and were observed to be broad, that is, over a large range of temperatures (Figure S15), which is analogous to previously reported ethylene copolymers containing polar comonomers. ,,, As a result of this broad T m , a clear identification of a T g was not possible for P­( E - co - M2 ) synthesized at 500 bar (Figure S15b). It should be noted that the copolymers do not have the same M n , which strongly impacts their crystallinity, as observed for P­( E - co - M1 ) synthesized at 50 and 500 bar, which contained the same amount of polar monomer (16 mol %) but had different crystallinities (4.5 and 9.5%, respectively; entries 4 and 5, Table ).…”

Aliphatic Polyester Materials from Renewable 2,3-Butanediol

“…The reduced crystallinity, resulting from the presence of methyl branches, can account for these differences. The observed properties are in the range of properties found for LDPE ( E t = 240 MPa, σ y = 12 MPa, ε tb = 653%) …”

Polyethylene materials with in-chain ketones from nonalternating catalytic copolymerization

“…Indeed, tensile tests on injection molded test bars showed a ductile behavior comparable to commercial HDPE (Fig. 3D): modulus of elasticity E = 1062 ± 53 MPa and tensile strength σ y = 26.7 ± 0.2 MPa, compared with literature values of E = 900 MPa and σ y = 27 MPa for HDPE, and E = 240 MPa and σ y = 12 MPa for LDPE ( 31 ). No evidence for undesirable cross-linking that could hamper melt processing was observed; cross-linking promoted by keto motifs has previously been an issue in the thermoplastic processing of commercial polyketone resins ( 32 ).…”