Hardness molar refractivity index

In order to gauge both homo and hetero aromaticity, hardness (ii) [88-92] is expresssed in terms of molar refractivity index as shown in Equation 2.17... 

The error in (a) is stated to compare favourably with calibration from benzene, since the absolute value of R90 is hardly known to this accuracy. In (b) the concentration of DNA was measured spectrophotometrically via the molar phosphorous extinction coefficient of 6415 (with a standard deviation of 2%). The low error in (c) arises from low levels of dust achieved as well as the integration over a period of 10 secs of the readings on a digital output. The specific refractive index increment used in (d) was an experimental one from the literature. In point of fact the assess-... 

Molar refractivity is easily derived from the refractive index. Hardness measured in this way correlates with other aromaticity criteria such as resonance energy per electron for a variety of hydrocarbons and heterocyclic molecules (see p. 141) ... 

The experimental results have shown that the BEPTES/ESDGEBA cured resins have a high refractive index that increases linearly with the content of BEPTES. The introduction of ESDGEBA into the copolymerization system can improve both surface hardness and the Eg of the cured resins. For the BEPTES/TDI system, the refractive index increases linearly with the increase of molar ratio of BEPTES to TDI. 

The optical properties of interest are refractive index and molecular refraction, polarisation, double refraction (birefringence) of isotropic and oriented PE, clarity, transparency, haze, and gloss (see Tables 3.1 and 3.9). PE granules are white and translucent, but the final appearance varies from hard, rigid, brightly coloured, glossy, flexible or transparent film to high-tenacity fibre. In the melt state the refractive index is 1.4297 and 1.4432 and the molar refractivity is 0.3297 and 0.32986 for HDPE and LDPE, respectively. 

---