Linear chain copolymers

Ethylene-Chlorotrifluoroethylene Copolymer. Ethylene-chlorotrilluoroethylene copolymer consists of linear chains in which the predominant 1 1 alternating copolymer is... 

One of the main uses of the linear a-olefins prepared by oligomerization of ethylene is in the preparation of linear low-density polyethylene. Linear low-density polyethylene is a copolymer produced when ethylene is polymerized in the presence of a linear a-olefin such as 1-decene [H2C=CH(CH2)7CH3]. 1-Decene replaces ethylene at random points in the growing polymer chain. Can you deduce how the structure of linear low-density polyethylene differs from a linear chain of CH2 units ... 

The possibility, through living cationic polymerization processes, to produce linear chain phosphazene copolymers [486]... 

The effects of architecture and block mass on the morphology and properties of linear multiblock copolymers was investigated by Spontak et al. [43]. They compared two matched series of compositionally symmetric (PS-fc-PI) block copolymers with 1 < n < 4, one possessing a constant chain mass and the other one having a nearly constant block mass. 

Figure 14. The phase diagram of the gradient copolymer melt with the distribution functions g(x) = l — tanh(ciit(x —fo)) shown in the insert of this figure for ci = 3,/o = 0.5 (solid line), and/o — 0.3 (dashed line), x gives the position of ith monomer from the end of the chain in the units of the linear chain length. % is the Flory-Huggins interaction parameter, N is a polymerization index, and/ is the composition (/ = J0 g(x) dx). The Euler characteristic of the isotropic phase (I) is zero, and that of the hexagonal phase (H) is zero. For the bcc phase (B), XEuier = 4 per unit cell for the double gyroid phase (G), XEuier = -16 per unit cell and for the lamellar phases (LAM), XEuier = 0.

The molecular weight (M 10,200,000) represents the highest molecular weight known to date for a linear, synthetic copolymer. DFT calculations suggest that steric congestion, derived from the triethylsilyl group and the amine moiety, near the polymerization reaction center diminishes the rates of chain termination or transfer processes yet permits the monomer access to the active site and the monomer s insertion into the metal-carbon bond (Fig. 21). 

The most simple diblock copolymers are linear chains, in which one part of the chain consists of one type of monomer, say polystyrene (PS), and the other one of another type, say polybutadiene (PB), as illustrated in Figure 14. PS and PB usually phase separate at low temperatures however, because of their chemical connectivity, block copolymers cannot unmix on a macroscopic scale. They can only phase separate on a microscopic scale, the size of which is determined by the length of the polymers. 

Copolymer molecules comprising a single species of linear chain Rule 3... 

In naming non-linear copolymer molecules having linear subchains of two or more types, the italicized connective for the skeletal structure is placed between the source-based names of the types of constituent linear subchains. In the case of branched and comb-like macromolecules, the linear chain named before the connective is that which forms the main chain, whereas that (those) named after the connective forms (form) the side-chain(s). The names of different species of side-chain are separated by semicolons. In the case of variegated star macromolecules the prefix is placed before the name of the macromolecule with the different species of arms separated by semicolons. 

The broad applicability of ATRP in the ionic liquid [BMIMjPFg was shown by extending it to the polymerization of N-substituted maleimides with styrene. The ATRP was initiated with dendritic polyaryl ether 2-bromoisobutyrate as the initiator at room temperature. The dendritic-linear block copolymers formed in the ionic liquid were characterized by low polydispersity (1.05chain-extension polymerization, suggesting the living nature of the polymerization 247). 

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