PlumX Metrics
Embed PlumX Metrics

Monte carlo simulation of short chain branched polyolefins: Structure and properties

Macromolecules, ISSN: 0024-9297, Vol: 45, Issue: 20, Page: 8453-8466
2012
  • 28
    Citations
  • 0
    Usage
  • 35
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    28
    • Citation Indexes
      28
  • Captures
    35

Article Description

The effect of higher α-olefin comonomer on physical properties of short chain branched (SCB) polyethylene (PE) melts at 450 K has been studied using connectivity altering Monte Carlo simulations. The calculated chain dimensions per molecular mass scale with backbone weight fraction, β, as 〈S 〉/M ∼ β for the radius of gyration S and 〈R 〉/M ∼ β for the end-to-end distance R, in very good agreement with the experiment-based result 〈R 〉/M ∼ β . The observed dependence is consistent with the decrease in the fraction of trans states along the backbone. The entanglement tube diameter, a , computed for SCB melts scales as 〈a 〉 ∼ β , which is close to the result for model concentrated (〈R 〉 = const) PE solutions created by deleting randomly chosen chains from equilibrated melt configurations of linear PE (〈a 〉 ∼ β ). The latter result agrees very well with the scaling based on rheological experiments on concentrated hydrogenated polybutadiene (HPB)/C H solutions at 413 K (〈a 〉 ∼ β ). The tube diameter in model athermal PE solutions scales as 〈a 〉 ∼ β , in excellent agreement with the scaling based on the neutron spin-echo experiments on athermal HPB/C D solutions at 509 K (〈a 〉 ∼ β ). The computed scaling relationships for both SCB melts and model PE solutions are close to the binary contact model (a ∼ β ) and disagree with the packing model (a ∼ β ). The solubility parameters calculated for poly(ethylene-co-1-butene) (PEB) melts are in excellent agreement with relative solubility parameters based on SANS analysis of appropriate SCB blends, which scale as δ ∼ β . The SANS-derived relative solubility parameters for poly(ethylene-co-1-hexene) (PEH) and poly(ethylene-1-octene) (PEO) systems scale more weakly (δ ∼ β ) and suggest breakdown of a universal correlation. This pattern is followed by simulated relative solubility parameters. © 2012 American Chemical Society.

Bibliographic Details

Krzysztof Moorthi; Kazunori Kamio; Javier Ramos; Doros N. Theodorou

American Chemical Society (ACS)

Chemistry; Materials Science

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know