|Kristiansen, P.M.; Greß, A.; Smith, P.; Hanft, D.; Schmidt, H.-W.: Phase behavior, nucleation and optical properties of the binary system isotactic polypropylene/N,N',N''-tris-isopentyl-1,3,5-benzene-tricarboxamide, Polymer, 47, 249-253 (2006) -- DOI: 10.1016/j.polymer.2005.08.053|
The phase behavior of the binary system consisting of previous termisotactic polypropylenenext term (i-PP) and N,N′,N″-tris-isopentyl-1,3,5-benzene-tricarboxamide (1)a selected member of a class of novel, versatile designer nucleating/clarifying agentswas investigated over the entire additive concentration range by means of differential scanning calorimetry (DSC) and optical microscopy. Experimental phase diagrams were constructed from data obtained in melting and crystallization studies, and a simple monotectic is advanced, very similar to the previously studied binary system i-PP/1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (DMDBS). In contrast to the latter, the crystallization temperature in the present system i-PP/1 was found to increase to not, vert, similar120 °C already at the lowest additive concentration employed and remained constant at further increasing additive concentration. Liquidliquid phase separation was observed at elevated temperatures for i-PP/1 mixtures comprising more than not, vert, similar2 wt% of 1. A study on the optical properties of the i-PP/1 system revealed that the values for haze and clarity of injection-molded plaques progressively decreased and increased, respectively, in the concentration range up to 0.15 wt%. An intermediate region of fairly concentration-independent optical properties was found between 0.15 and 1 wt%, followed by a rapid increase in haze at concentrations exceeding 2 wt%.