Polyethylene, solid-state

The reported bathochromic shift of 20 nm (solution solid state) can be explained by a model that sugggests 2° complete planarization of the conjugated PPE backbones in the polyethylene matrix by the draw-induced order. TEM investigations on materials with high PPE content but polyethylene solid-state structure would be extremely interesting. 

Della, C.N., Dongwei, S. Mechanical properties of carbon nanotubes reinforced ultra high molecular weight polyethylene. Solid State Phenom. 136, 45-49 (2008)... 

TABLE 2.11 Typical Properties of Unfilled Polyethylene terephthalate) (PET), Poly(trimethylene terephthalate) (PTT), and Poly(butylene terephthalate (PBT) Solid-State Polyester Resins... 

J. Schumacher, M. Jackel, A. Leder, M. Petesch, and Y. Sakuma, Polyethylene Terephthalate Solid-State Resins, CEH Report, SRI Consulting, Menlo Park, CA, July 1997. 

Kitamaru, R, Phase Structure of Polyethylene and Other Crystalline Polymers by Solid-State l3C/MNR.VoL 137, pp 41-102. 

There are numerous variations on the basic linear structure of polymers. Returning to our example of polyethylene, we find short chain branches and long chain branches, as shown in Figs. 1.2 and 1.3, respectively. The number and type of these branches strongly influences the way that the molecules pack in the solid state, and hence affect the physical properties. Long... 

In practice, product developers often blend two or more resins together in order to obtain a product that has the required melt flow and solid-state characteristics. Thus, we frequently combine metallocene catalyzed linear low density polyethylene, having a most probable molecular weight distribution, with low density polyethylene, having a broad molecular weight distribution. The linear low density polyethylene provides good impact resistance, while the low density polyethylene improves melt flow characteristics. 

Both polyethylene terephthalate and polybutylene terephthalate exhibit partial crystallinity in the solid state. The molecular weight of the polymer and the time permitted for cooling define the degree of crystallinity of the polymer. Very slow cooling results in high crystallinity and opacity, while fast quenching creates low crystallinity, high clarity material. 

An increase in rod-like arrangement of the macromolecules can also arise by stretching a polymer either in its solid state, either in the melt or even in solution (for polymers leading to lyotropic liquid crystals such as aromatic polyamides). This is the basis of the development of synthetic fibres including high modulus polyethylene Dyneema , polyamide Nylons and Kevlar , polyester Tergal or Dacron fibres. 

In very few cases solid-state NMR has been used to determine molecular weights for polyethylene [99]. In general solid-state NMR is not so suitable due to the long relaxation times of the end groups, which lead to long measurement times. The strength of NMR is in chemical structure characterization and also the possibility to determine the chain branching, tacticity or to obtain further details of the microstructure. 

Percent elongation at rupture as a function of the composition of mixed of polypropylene and polyethylene indicating influence of solid state phases on strength and extensibility. 

Ravindranath, K. and Mashelkar, R. A., Modeling of polyethylene terephthalate) reactors. IX. Solid state polycondensation process,./. Appl. Polym. Sci., 39, 1325-1345 (1990). 

Wu, D., Chen, F. and Li, R., Reaction kinetics and simulations for solid-state polymerization of polyethylene terephthalate), Macromolecules, 30, 6737-6742 (1997). 

Devotta, I. and Mashelkar, R. A., Modelling of polyethylene terephthalate reactors - X. A comprehensive model for a solid-state polycondensation process, Chem. Eng. Sci., 48, 1859-1867 (1993). 

Droscher, M. and Wegner, G., Polyethylene terephthalate) a solid state condensation process, Polymer, 19, 43-47 (1978). 

Moller, K. and Gevert, T. 1994, An FTIR solid-state analysis of the diffusion of hindered phenols in low-density polyethylene (LDPE) the effect of molecular size on the diffusion coefficient. J. Appl. Polym. Sci. 51 895-903. 

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