Two component polyurethane (PU) flame retardant coatings were prepared by blending trichloro modified polyesters (TCMPs) and isophorone diisocyanate isocyanurate. TCMPs were synthesized by polycondensation of trichlorobenzoic acid (TCBA), a flame retardant component, with adipic acid, 1,4 butanediol, and trimethylolpropane. The content of TCBA was varied in 10, 20, and 30 wt% for the reaction. Theses new flame retardant coatings showed various properties comparable to other non flame retardant coatings. Moreover, we carried out the combustion test and the flammability test for our flame retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TCBA were determined as no burn. The results of flammability test for the coatings with 20 wt% and 30 wt% of TCBA contents indicated the limiting oxygen index (LOI) values of 26% and 29% respectively, which implied relatively good flame retardancy.

We present BV CCD photometry for the open clusters Czernik 24 and Czernik 27. These clusters have never been studied before, and we provide, for the first time, the cluster parameters; reddening, distance, metallicity and age. Czernik 24 is an old open cluster with age 1.8 ± 0.2 Gyr, metallicity [Fe/H]=-0.41 ± 0.15 dex, distance modulus (m-M)0=13.1 ± 0.3 mag (d=4.1 ± 0.5 kpc), and reddening E(B-V)=0.54 ± 0.12 mag. The parameters for Czernik 27 are estimated to be age=0.63 ± 0.07 Gyr, [Fe/H]=-0.02 ± 0.10 dex, (m-M)0=13.8 ± 0.2 mag (d=5.8 ± 0.5 kpc), and E(B-V)=0.15 ± 0.05 mag. The metallicity and distance values for Czernik 24 are consistent with the relation between the metallicity and the Galactocentric distance of other old open clusters. We find the metallicity gradient of 51 old open clusters including Czernik 24 to be Δ[Fe/H]/ΔRgc = -0.064±0.009 dex kpc-1.