Characterization of homogeneous ethylene/1‐octene copolymers made with a single‐site catalyst. CRYSTAF analysis and calibration

Efficient Synthesis of Novel Polyethylene Graft Copolymers Containing Polyfluorosiloxane Side Chains

“…Figure displays the linear decrease in the melting temperature. This behavior resulted from the higher branch density and reduction of consecutive ethylene units, which consequently led to the reduction of lamella thickness of the semicrystalline polymer structure. , According to the findings from Monrabal et al, this linear dependency implied that PMTFPS side chains were randomly distributed in PE- g -PMTFPS graft copolymers, which was consistent with the result concluded by reactivity ratios . The successive self-nucleation and annealing characterization was conducted to further delineate the chemical composition distribution of resulting copolymers.…”

Efficient Synthesis of Novel Polyethylene Graft Copolymers Containing Polyfluorosiloxane Side Chains

“…Figure displays the linear decrease in the melting temperature. This behavior resulted from the higher branch density and reduction of consecutive ethylene units, which consequently led to the reduction of lamella thickness of the semicrystalline polymer structure. , According to the findings from Monrabal et al, this linear dependency implied that PMTFPS side chains were randomly distributed in PE- g -PMTFPS graft copolymers, which was consistent with the result concluded by reactivity ratios . The successive self-nucleation and annealing characterization was conducted to further delineate the chemical composition distribution of resulting copolymers.…”

Using Probability Models to Design the Microstructure of Linear Olefin Block Copolymers

“…The CCD becomes noticeably narrower with increasing P p (also an expected outcome), the average 1-octene content and peak locations remain practically the same, and higher P p values lead to the production of longer OBC chains (in average) but do not affect average 1-octene incorporation in C 1 or C 2 . The 1-octene fraction in the longer chains, however, will be closer to their average value in the whole population (following the law of large numbers), thus narrowing the CCD. , Similar results for random ethylene/1-olefin copolymers have been observed via simulation using the Stockmayer bivariate distribution and/or through experimental results. − The effect of propagation probabilities on the NBD was negligible as long as the ratio between P s and P t was kept constant.…”

“…Contrarily, the average 1-octene fraction increased for higher P c 1 values because we assumed that C 1 was a better 1-octene incorporator than C 2 ( P p ,2 1 > P p ,2 2 ). For random ethylene/1-olefin copolymers, the CCD broadens and the peak magnitude lowers as the fraction of 1-olefin in the copolymer increases (up to 50 mol %), − but for the simulated OBC sample, the broadest CCD was observed when P c 1 = 0.5 because, in this case, the chain-shuttling mechanism produces chains with the highest number of blocks, and thus a broader comonomer distribution. Likewise, when P c 1 = 0.5, the distribution of the number of blocks (NBD) becomes the broadest; narrower NBDs are observed when one of the catalysts is much more likely to be selected than the other (that is, P c 1 approaches 0 or 1).…”

Temperature Rising Elution Fractionation and Crystallization Analysis Fractionation

“…87 Although most single-site catalyst resins show a narrow CCD, some catalysts result in resins with broad and tailing CCD, especially with supported catalysts. The CCD of metallocene-type resins has been found experimentally to be broader for the lower M w resins 55 and this has been shown to fit well with Stockmayer's distribution prediction. 88 The commercial introduction of homogeneous singlesite catalysts (metallocenes), which result in resins with narrow CCD and molecular weight distributions, and their combination with Ziegler-type resins, through blending or multiple catalyst -reactor processes, provides broad designing capabilities for new products and the need to determine the percentages of the various components present.…”

Efficient Synthesis of Novel Polyethylene Graft Copolymers Containing Polyfluorosiloxane Side Chains

“…Figure displays the linear decrease in the melting temperature. This behavior resulted from the higher branch density and reduction of consecutive ethylene units, which consequently led to the reduction of lamella thickness of the semicrystalline polymer structure. , According to the findings from Monrabal et al, this linear dependency implied that PMTFPS side chains were randomly distributed in PE- g -PMTFPS graft copolymers, which was consistent with the result concluded by reactivity ratios . The successive self-nucleation and annealing characterization was conducted to further delineate the chemical composition distribution of resulting copolymers.…”

Using Probability Models to Design the Microstructure of Linear Olefin Block Copolymers

“…The CCD becomes noticeably narrower with increasing P p (also an expected outcome), the average 1-octene content and peak locations remain practically the same, and higher P p values lead to the production of longer OBC chains (in average) but do not affect average 1-octene incorporation in C 1 or C 2 . The 1-octene fraction in the longer chains, however, will be closer to their average value in the whole population (following the law of large numbers), thus narrowing the CCD. , Similar results for random ethylene/1-olefin copolymers have been observed via simulation using the Stockmayer bivariate distribution and/or through experimental results. − The effect of propagation probabilities on the NBD was negligible as long as the ratio between P s and P t was kept constant.…”

“…Contrarily, the average 1-octene fraction increased for higher P c 1 values because we assumed that C 1 was a better 1-octene incorporator than C 2 ( P p ,2 1 > P p ,2 2 ). For random ethylene/1-olefin copolymers, the CCD broadens and the peak magnitude lowers as the fraction of 1-olefin in the copolymer increases (up to 50 mol %), − but for the simulated OBC sample, the broadest CCD was observed when P c 1 = 0.5 because, in this case, the chain-shuttling mechanism produces chains with the highest number of blocks, and thus a broader comonomer distribution. Likewise, when P c 1 = 0.5, the distribution of the number of blocks (NBD) becomes the broadest; narrower NBDs are observed when one of the catalysts is much more likely to be selected than the other (that is, P c 1 approaches 0 or 1).…”

Temperature Rising Elution Fractionation and Crystallization Analysis Fractionation

“…87 Although most single-site catalyst resins show a narrow CCD, some catalysts result in resins with broad and tailing CCD, especially with supported catalysts. The CCD of metallocene-type resins has been found experimentally to be broader for the lower M w resins 55 and this has been shown to fit well with Stockmayer's distribution prediction. 88 The commercial introduction of homogeneous singlesite catalysts (metallocenes), which result in resins with narrow CCD and molecular weight distributions, and their combination with Ziegler-type resins, through blending or multiple catalyst -reactor processes, provides broad designing capabilities for new products and the need to determine the percentages of the various components present.…”

Efficient Synthesis of Novel Polyethylene Graft Copolymers Containing Polyfluorosiloxane Side Chains

“…Figure displays the linear decrease in the melting temperature. This behavior resulted from the higher branch density and reduction of consecutive ethylene units, which consequently led to the reduction of lamella thickness of the semicrystalline polymer structure. , According to the findings from Monrabal et al, this linear dependency implied that PMTFPS side chains were randomly distributed in PE- g -PMTFPS graft copolymers, which was consistent with the result concluded by reactivity ratios . The successive self-nucleation and annealing characterization was conducted to further delineate the chemical composition distribution of resulting copolymers.…”

Using Probability Models to Design the Microstructure of Linear Olefin Block Copolymers

“…The CCD becomes noticeably narrower with increasing P p (also an expected outcome), the average 1-octene content and peak locations remain practically the same, and higher P p values lead to the production of longer OBC chains (in average) but do not affect average 1-octene incorporation in C 1 or C 2 . The 1-octene fraction in the longer chains, however, will be closer to their average value in the whole population (following the law of large numbers), thus narrowing the CCD. , Similar results for random ethylene/1-olefin copolymers have been observed via simulation using the Stockmayer bivariate distribution and/or through experimental results. − The effect of propagation probabilities on the NBD was negligible as long as the ratio between P s and P t was kept constant.…”

“…Contrarily, the average 1-octene fraction increased for higher P c 1 values because we assumed that C 1 was a better 1-octene incorporator than C 2 ( P p ,2 1 > P p ,2 2 ). For random ethylene/1-olefin copolymers, the CCD broadens and the peak magnitude lowers as the fraction of 1-olefin in the copolymer increases (up to 50 mol %), − but for the simulated OBC sample, the broadest CCD was observed when P c 1 = 0.5 because, in this case, the chain-shuttling mechanism produces chains with the highest number of blocks, and thus a broader comonomer distribution. Likewise, when P c 1 = 0.5, the distribution of the number of blocks (NBD) becomes the broadest; narrower NBDs are observed when one of the catalysts is much more likely to be selected than the other (that is, P c 1 approaches 0 or 1).…”

Temperature Rising Elution Fractionation and Crystallization Analysis Fractionation

“…87 Although most single-site catalyst resins show a narrow CCD, some catalysts result in resins with broad and tailing CCD, especially with supported catalysts. The CCD of metallocene-type resins has been found experimentally to be broader for the lower M w resins 55 and this has been shown to fit well with Stockmayer's distribution prediction. 88 The commercial introduction of homogeneous singlesite catalysts (metallocenes), which result in resins with narrow CCD and molecular weight distributions, and their combination with Ziegler-type resins, through blending or multiple catalyst -reactor processes, provides broad designing capabilities for new products and the need to determine the percentages of the various components present.…”