240 



TABLE 231.— PROPERTIES OF SOME OPTICAL PLASTICS 78 



Polymer 



Name "i> v 



Allyl methacrylate 1.5196 49.0 



Benzyl mellacrylate 1.5680 36.5 



4-cyctolaxyl-cyclohexyl metharcylate .... 1.5250 53. 



Menthyl metharcylate 1.5064 54.5 



Ethylene dimethacrylate 1.5063 53.4 



Methyl methacrylate 1.490 56.25 



Styrene 1.5916 31.0 



O-chlorostyrene 1.6098 31.0 



Pentachlorophenol methacrylate 1.608 22.5 



Vinyl naphthalene 1.6818 20.9 



78 Polaroid Corporation, NDRC Report, Library of Congress PB 28553. 

 * See Table 523. 



TABLE 232.— GENERAL PROPERTIES OF OPTICAL PLASTICS 



Cyclo- 

 hexyl- 

 metha- 

 crylate 



Index N D 20°C . . 1.50645 

 Index tolerance . +0015 



v values 56.9 



" " tolerance. +.5 



Partial dispersion 



Nf-Nc 00895 



Nd-Nc 00258 



Np-Nd 00638 



Sterene 



1.59165 

 +.0015 



31.0 



+.3 



.01920 

 .00536 

 .01384 



Thermal exp. coeff. ... 

 Thermal conductivity. 



Index charge per °C. . 

 Max. operating temp.. 



Cyclo- 

 hexyl- 

 metha- 

 crylate 



9.0Xl0" 5 / o C 

 2.31 X10" 4 



(cgs) 

 -.000131 

 150°F 



Density 1.095 g/cm* 



Moles hardness 2-3 



Over-all visual trans- 

 mittance through sam- 

 ple I in. thick 99.1% 



Sterene 



8.0Xl0- 5 /°C 

 2.21 X10- 4 

 cal sec" 1 cm" 10 C 

 —.000136 

 150°F 



1.049 g/cm 3 

 2-3 



99.9% 



SMITHSONIAN PHYSICAL TABLES 



