Molar mass of a monomer

For polymers, the degree of polymerization P is often used instead of the molar mass M. The degree of polymerization describes how many monomer units make up a polymer molecule. The molar mass M can be calculated from the degree of polymerization, if the molar mass of a monomer unit in the chain M is known ... 

The molar mass of a monomer unit can be calculated through simple addition... 

Number average molar mass Molar mass of a monomer unit Mass average molar mass Centrifuge average molar mass Viscosity average molar mass... 

Mm describes the molar mass of a monomer). In addition, one introduces a modified second virial coefficient, A2, defined as... 

The number of monomers per chain is also called degree of polymerization Nop. The degree of polymerization is linked to the molar mass of a polymer by NdpMj. Here, Mr is the molar mass of a monomer. Molar masses of a polymer can be measured in different ways, for example, by gel permeation chromatography (GPC) or high-pressure liquid chromatography (HPLC). For polymers in solution, the molar mass can be determined from the depression of the melting point, vapor pressure decrease, and osmotic pressure measurements. 

Relate the molar mass of a polymer to the number of monomer units. 

C13-0084. Compute the molar mass of a polyethylene molecule that has 744 monomer units. 

Quantitative characteristics of a macromolecule or an assembly of macromolecules, such as mass and mole fractions or percentages as well as the degrees of polymerization and molar masses, may be expressed by placing corresponding figures after the complete name. The order of citation is the same as for the monomer species in the name. Some characteristics cannot be defined for all types of macromolecules and assemblies dealt with in this document, e.g. molar mass of a network. 

Consistent notation is adopted throughout this book. Diblock copolymers are written poly(monomer A) poly (monomer B) or PA-PB, where examples of PA and PB are illustrated in Fig. 1.2. Similarly, triblock copolymers are written poly(monomer A)-poly(monomer B)-poly(monomer C) or PA-PB PC. Deuterated blocks are denoted dpoly(monomer A) or dPA. The molar mass of a copolymer is denoted by M, or Af corresponding to the weight- or number-average respectively, and the composition is specified by the volume fraction of one component,/. In solution, the volume fraction of a copolymer is denoted [Pg.3]

Let us consider a homopolymer of initial molar mass Mn0 (molar mass of the monomer unit m0) and a critical molar mass (entanglement threshold... 

Molar mass—The average mass of a polymer molecule equals DP times molar mass of the monomer ... 

Fig.1. Dry thickness h0 of various PDMS layers irreversibly adsorbed on the silica surface of a silicon wafer, as a function of the scaling variable Nm 0m. N is the polymerisation index of the surface anchored chains and(])0 is the polymer volume fraction in the incubation bath. The triangles correspond to 4>0=1, i.e., to the maximum surface density of anchored chains for the particular molecular weight. The range of molecular weights used is 29.6 kg mol-1

The number-average is the common average used, for example, to determine the average denomination of the coins in your pocket. The number traction of each type of coin (n ) is multiplied by its denomination Mm)-Substituting Eq. (1.27) into Eq. (1.23) shows that the ratio of the molar mass of a polymer with AT monomers and the number-average molar mass Mn relates the number fraction and weight fraction of molecules ... 

The values of the Kuhn length b and corresponding molar mass of a Kuhn monomer Mq for various polymers are listed in Table 2.1. Throughout this book, we will use the equivalent freely jointed chain to describe all flexible polymers and will call N the degree of polymerization or number of monomers (short for Kuhn monomers) and call b the monomer length (instead of the Kuhn monomer length) and... 

The typical experimental concentration used in defining intrinsic viscosity is the polymer mass per unit volume of solution, c = 4)Mq/ PNAy) where Mq is the molar mass of a Kuhn monomer [see Eq. (1.18)]. The intrinsic "viscosity then follows ---------------------------... 

Consider tor example, a melt of 1,4-poly butadiene linear chains with M—130000gmol The molar mass of a polybutadiene Kuhn monomer is Mo= I05gmol (see Table 2.1) so this chain has N = MjMo 1240 Kuhn monomers. At 25 °C, this polymer is 124 K above its glass transition and its oscillatory shear master curve is shown in Fig. 9.3. The time scale for monomer motion is tq = 0.3 ns, An entanglement strand of 1,4-polybutadiene has molar mass M — I900gmol (see Table 9.1) and therefore contains N — M jMQ= % Kuhn monomers. The whole chain has N/Ne = MjMs 68 entanglements. The Rouse time of the entanglement strand Te = 0.1 ps [Eq. (9,16)]. 

Consider a PDMS melt with molar mass A/ = 6 X 10 g mol . The relaxation time of a Kuhn monomer is tq — 10 s. The molar mass of a Kuhn monomer is Mo = 381g moC and the molar mass of an entanglement strand is jWg 12000g mol ... 

Nylon was designed to be a synthetic silk, (a) The average molar mass of a batch of nylon 66 is 12,000 g/mol. How many monomer units are there in this sample (b) Which part of nylon s structure is similar to a polypeptide s structure (c) How many different tripeptides (made up of three amino acids) can be formed from the amino acids alanine (Ala), glycine (Gly), and serine (Ser), which account for most of the amino acids in silk ... 

The degree of polymerization, P, and the molar mass (or molecular weight), M, are some of the most important characteristics of a macromolecular substance. They indicate how many monomer units are linked to form the polymer chain and what their molar mass is. In the case of homopolymers, the molar mass of a macromolecule is given by... 

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