Rheological, thermal and crystallisation properties of ethylene, propylene and α-olefin copolymers. II Thermal and crystallisation properties

Abstract

A series of random ethylene, propylene/1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene copolymers, ethylene and propylene homopolymers were prepared and investigated. The thermal and crystallisation properties of copolymer samples with different co-unit content and molecular masses were determined and compared with the properties of homopolymers. The effects of the length of co-unit and the comonomer content were investigated. The thermodynamic melting point was determined by linear and non-linear methods. The melting points and crystallinity decrease with the length of co-unit and with the increase in comonomer content. The crystallisation kinetics was investigated with the Avrami equation.

Precision Polyethylene: Changes in Morphology as a Function of Alkyl Branch Size

“…( range of applications. [16][17][18][19][20][21][22][23][24] Furthermore, metallocene copolymerization of ethylene with nonlinear, bulkier R-olefins such as 3-methyl-1-butene, [25][26][27][28] 4-methyl-1-pentene, [29][30][31][32] vinylcyclohexene, [33][34][35][36] and norbornene 28 has created a new class of materials with better impact strength than that of traditional ethylene linear R-olefin copolymers. By its nature, copolymerization of ethylene with R-olefins via chain-propagation chemistry incorporates structural defects via head-to-head or tail-to-tail monomer coupling.…”

“…Copolymerization via metallocene chemistry of ethylene with odd-carbon-number α-olefins (e.g., 1-pentene or 1-heptene) is also feasible, because such compounds are available using the Fischer−Tropsch olefin synthesis process. These possibilities have led to the creation of a significant number of ethylene/α-olefin copolymers with a wide range of applications. − Furthermore, metallocene copolymerization of ethylene with nonlinear, bulkier α-olefins such as 3-methyl-1-butene, − 4-methyl-1-pentene, − vinylcyclohexene, − and norbornene has created a new class of materials with better impact strength than that of traditional ethylene linear α-olefin copolymers.…”

The existence of human TII B cells remains unproven: Comment on the article by Daridon et al

“…However, there are few works on ethylene‐1‐pentene and propylene‐1‐pentene copolymers and to our knowledge any work on ethylene‐propylene‐1‐pentene terpolymers. Ethylene‐1‐pentene copolymers have been studied concerning their chemical distribution14 and thermal, crystallization, and reological properties15 and propylene‐1‐pentene random copolymers having high impact strength, good tensile and reological properties, excellent optical properties and a large processing window have been prepared 16. The 13 C NMR spectroscopy is the most successful analytical tool to study molecular structure of polymers and allows researchers to obtain comonomer sequences, short‐chain and long‐chain branch distributions, and quantitative analyses of the composition 17, 18.…”

Investigation on chain structure of LLDPE obtained by ethylene in-situ copolymerization with DSC and XRD

“…The molecular structure of LLDPE has been investigated from different angles, such as the average content of comonomer, the intramolecular comonomer sequence distribution, and the distribution of comonomer among polymer chains, in addition to average molecular weights and molecular weight distribution. Halasz et al [1] studied a series of ethylene/1-pentene, ethylene/1-hexene, and ethylene/1-octene copolymers and concluded that the melting temperatures and the crystallinity decrease with increasing chain length of the comonomer and the comonomer content. Moreover, they have investigated the crystallization kinetics of these copolymers.…”