The relation between chemical structure of branched amide nucleating agents and nucleation effect in isotactic polypropylene

• Published in: Journal of thermal analysis and calorimetry Vol. 145; no. 6; pp. 3053 - 3066
• Main Authors: Xia, Min-Qiang, Zhang, Yue-Fei
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2021; Springer; Springer Nature B.V
• Subjects: Amides; Analytical Chemistry; Benzamide; Benzene; Calorimetry; Chains; Chemistry; Chemistry and Materials Science; Crystallization; Hydrocarbons; Inorganic Chemistry; Isotacticity; Measurement Science and Instrumentation; Nucleation; Physical Chemistry; Polymer Sciences; Polypropylene; Substitutes; Branched amide compound; Aliphatic C5; Structure; Nucleation effect; Isotactic iPP; Nucleating agent
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-020-09860-z

The relation between chemical structure of branched amide compounds as nucleating agents and the nucleation effect of them in isotactic polypropylene (iPP) was investigated through studying the crystallization and melting behavior of iPP nucleated with these nucleating agents by differential scanning calorimetry (DSC). The crystallization peak temperature ( T c ) of nucleated iPP had different degrees of increase after the amide groups were introduced into the benzene ring. The nucleation efficiency of 1,3,5-benzenetrisamide was superior to that of terephthalamide due to the existence of benzamide. At the same time, the nucleation effect of different side chain-substituted amide compounds on iPP was investigated. The results showed that the crystallization peak temperature of iPP nucleated with ring-substituted amides was higher than that of iPP nucleated with chain-substituted amides, that of the 6-membered ring-substituted amides was better than that of the five-membered ring-substituted amides and that of the cyclohexyl group substitution was superior to that of the benzene ring. Besides, the amide compounds with different central group were also studied as iPP nucleating agents. The results show that the sequence of nucleating efficiency from high to low is six carbons > benzene >  ten carbons. In addition, the optimum contents of 1,3,5-benzenetricarboxylic acid tris(cyclopentylamine) (BTA-CP), 1,3,5-benzenetricarboxylic acid tris(tert-pentylamine) (BTA-TP) and 1,3,5-benzenetricarboxylic acid tris(iso-pentylamine) (BTA-IP) in iPP were 0.20 mass%, 0.20 mass% and 0.15 mass%, respectively. Under the optimum content of BTA-CP, BTA-TP and BTA-IP, the crystallization peak temperature of nucleated iPP was increased from 117.6 °C of pure iPP to 127.2°C, 125.7°C and 123.4 °C, respectively.