Crystallization of isotactic polypropylene in the presence of a β‐nucleating agent based on a trisamide of trimesic acid

Abstract

Tris-2,3-dimethyl-hexylamide of trimesic acid (TATA) is an new type of b-nucleating agent for isotactic polypropylene (iPP). The crystallization, melting characteristics, and the supermolecular structure of iPP nucleated with TATA were studied on the samples crystallized under nonisothermal and isothermal conditions. The b-nucleating ability of TATA was rather high even at low concentration. It was established that TATA possessed dual nucleating ability generating samples with mixed (a and b) polymorphic compositions. The b-content showed an maximum value at low concentrations (10-100 ppm) of TATA. The b-content decreased with increasing concentration of TATA in the higher concentration range. The highest b-content (about 80%) was achieved at the crystallization temperature T c ¼ 110-120 C at low concentration of TATA. The crystallization curves registered at constant cooling rate or under isothermal condition have a single peak in spite of the formation of two polymorphic modifications. The crystallization isotherms cannot be linearized according to the Avrami equation because of simultaneous crystallization of the a-and b-forms, having different nucleation and growth rate. It was also found that the b-content increased with increasing conversion during isothermal crystallization because of the higher growth rate of the b-phase. The b-phase formed in the presence of TATA consist of lamellar crystallites. In the early stage of the crystallization, hedritic structure is formed.

Melting and crystallization behaviors, morphology, and mechanical properties of β‐polypropylene/polypropylene‐graft‐maleic anhydride/calcium sulfate whisker composites

“…The enthalpies of the α form ( ) and β form were obtained by separating the areas of the α and β melting peaks by a “vertical line” method. The crystallinity values of the α ( X α ) and β forms ( X β ) as well as the β crystalline form content ( K DSC ) were calculated as follows: …”

Influence of different beta-nucleating agents on the morphology of isotactic polypropylene and their toughening effectiveness

“…Varga et al found for the beta-nucleating agent (N,N 0 ,N 00 -tris(2,3-dimethylcyclohexyl))-1,3,5-benzenetricarboxamide) a concentration-dependent behavior in iPP with a MFR of 0.35 and a maximum amount of beta modification at very low concentrations (around 100 ppm). However, no data regarding the mechanical properties of the beta-nucleated iPP were given [26]. In a previous study, we were able to show that this nucleating agent could be used to effectively increase the toughness of a high-MFR iPP [27].…”

Glass fiber reinforced and β‐nucleating agents regulated polypropylene: A complementary approach and a case study

“…Among these, the use of β‐NAs is considered as the most efficient and convenient way to prepare β‐phase . There are four categories of β‐NAs: (1) γ quinacridone (permanent Red E3B), (2) dicarboxylic acids and their group IIA salts, (3) aromatic amide compounds and its derivatives, such as N , N ′‐dicyclohexylterephthalamide, N , N ′‐dicyclohexylsuc‐cinamide, and N , N ′‐2,6‐naphthalene dicarboxamide, and (4) rare earth metal complexes . Moreover, an aromatic amide type β‐NA N , N ′‐dicyclohexyl‐2,6‐napthalene‐dicarboxamide (TMB‐5) has been reported as a highly efficient nucleating agent for PP to form β‐phase .…”