Does the length of the short chain branch affect the mechanical properties of linear low density polyethylenes? An investigation based on films of copolymers of ethylene/1-butene, ethylene/1-hexene and ethylene/1-octene synthesized by a single site metallocene catalyst

Towards the understanding of the molecular weight dependence of essential work of fracture in semi-crystalline polymers: A study on poly(ε-caprolactone)

“…[19][20][21][22]) the previously mentioned entropyelastic deformations dominate the failure, thus similar observations can be made than in case of amorphous thermoplastics and elastomers [17]. The other group of investigations includes materials, which were tested (ii) above their glass transition temperature, like polyethylenes [23,24], polypropylenes [19,20,[25][26][27][28], polyesters [21], poly(vinylidenefluoride) [29], etc. In these polymers the cold-drawing in the amorphous glass is less significant and the effect of crystallinity can be emphasized.…”

“…Conversely, the crack growth resistance decreased with increasing concentration of side chains. Gupta et al [24] studied the effect of side chain length on the deformation mechanisms of linear low density polyethylenes of similar molecular characteristics and crystallinity. They found that the longer the side chain the higher the essential work of fracture, which was explained by an anchoring effect of longer chain segments.…”

Analytical Rheology of Polymer Melts: State of the Art

“…Thus, the length and distribution of SCB can be tuned to control properties [24][25][26][27][28][29][30][31][32] such as crystallization kinetics, morphology, blend miscibility, mechanical properties of blown or compression molded films such as tear and impact strengths, and resistance to crack growth. Ultimate mechanical properties and crack resistance improve as the length of the side branch increases, possibly because SCB influences morphology and tie-molecule concentration, requiring greater energy to be absorbed to initiate cracks [33].…”

Catalytic Trimerization of Ethylene with Highly Active Half‐sandwich Titanium Complexes Bearing Pendant p‐Fluorophenyl Groups

“…[1][2][3][4] Compared to conventional oligomerization processes, the selective oligomerization of ethylene is highly desirable, because it would avoid the production of unwanted olefins. 1-Hexene, which is used as a comonomer for synthesis of linear low-density polyethylene (LLDPE), [5][6][7] can be produced by catalytic trimerization of ethylene. Although most catalytic trimerization systems are based on chromium compounds, 8,9 the research on non-chromium based trimerization systems is still in process, not only for potential productivity, but also for pollution reasons.…”

“…Although most catalytic trimerization systems are based on chromium compounds, 8,9 the research on non-chromium based trimerization systems is still in process, not only for potential productivity, but also for pollution reasons. 10 In 2002, Hessen and co-workers 10 reported that the half-sandwich titanium complexes [η 5 -C 5 H 4 -(bridge)-Ar]-TiCl 3 , activated by methylalumoxane (MAO), formed a family of highly active catalysts for the trimerization of ethylene, giving 1-hexene as main product. This discovery has triggered chemist's interest in developing group 4 metal complexes used in ethylene trimerization.…”