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The Flory–Fox equation relates the number-average molecular weight, M n, to the glass transition temperature, T g, as shown below: =, where T g,∞ is the maximum glass transition temperature that can be achieved at a theoretical infinite molecular weight and K is an empirical parameter that is related to the free volume present in the polymer sample.
Trimethylolpropane triglycidyl ether (TMPTGE) is an organic chemical in the glycidyl ether family. [2] [3] It has the formula C 15 H 26 O 6 and the IUPAC name is 2-[2,2-bis(oxiran-2-ylmethoxymethyl)butoxymethyl]oxirane, and the CAS number 3454-29-3.
Because it achieves an unusually high degree of polymerization, chain entanglements can be relied upon as anchor points to achieve the thermally induced shape-memory effect. Therefore, this polymer relies solely on physical anchor points. When heated up to Tg, the material abruptly changes from a rigid state to a tapered state (softens).
That is, is the total number of polymer segments (monomers) in the solution, so is the number of nearest-neighbor sites to all the polymer segments. Multiplying by the probability ϕ 1 {\displaystyle \phi _{1}} that any such site is occupied by a solvent molecule, [6] we obtain the total number of polymer-solvent molecular interactions.
The relative amount of each isomer in the polymer is dependent on the mechanism of the polymerization reaction. [citation needed] Anionic chain polymerization, which is initiated by n-Butyllithium, produces cis-1,4-polyisoprene dominant polyisoprene. 90–92% of repeating units are cis-1,4-, 2–3% trans-1,4- and 6–7% 3,4-units. [3]
[4] [5] Such conventions include a constant cooling rate (20 kelvins per minute (36 °F/min)) [2] and a viscosity threshold of 10 12 Pa·s, among others. Upon cooling or heating through this glass-transition range, the material also exhibits a smooth step in the thermal-expansion coefficient and in the specific heat , with the location of these ...
In the example, there is a bromo-substituted -CH 2-CH 2 - subunit. 1-Bromoethane-1,2-diyl is chosen in preference to 2- bromoethane-1,2-diyl as the former has a lower locant for the bromo-substituent. The preferred CRU is therefore oxy(1-bromoethane-1,2-diyl) and the polymer is thus named poly[oxy(1-bromoethane-1,2-diyl)].
It was the first conductive inorganic polymer discovered [1] [2] and was also found to be a superconductor at very low temperatures (below 0.26 K). [3] [4] It is a fibrous solid, described as "lustrous golden on the faces and dark blue-black", depending on the orientation of the sample. It is air stable and insoluble in all solvents.