Effect of molecular weight and polymer concentration on the triple temperature/pH/ionic strength-sensitive behavior of poly(2-(dimethylamino)ethyl methacrylate). Issue 9 (13th June 2017)

• Record Type: Journal Article
• Authors: Mohammadi, Maryam; Salami-Kalajahi, Mehdi; Roghani-Mamaqani, Hossein; Golshan, Marzieh
• Is Part Of: International journal of polymeric materials. Volume 66:Issue 9(2017)
• Page Start: 455
• Page End: 461
• Publication Date: 2017-06-13
• Subjects: Aqueous ATRP -- cloud point -- PDMAEMA -- stimuli-responsive behavior; Polymers -- Periodicals; Plastics -- Periodicals; 620.19205
• DOI: 10.1080/00914037.2016.1236340
• Languages: English
• ISSNs: 0091-4037

Abstract

ABSTRACT: Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) samples were synthesized via aqueous atom transfer radical polymerization with DP n of 35, 151, 390, and 546 and dispersity of 1.13, 1.17, 1.20, and 1.18, respectively. All samples were exposed to temperature and pH variations at different concentration of polymer and salt (NaCl). Results indicated that cloud point ( T cl ) can be controlled by changing DP n, polymer concentration, and ionic strength of solution. According to results, T cl of the PDMAEMA chains shifted to lower temperatures with increasing solution pH at all molecular weight ranges due to deprotonation of tertiary amine groups in polymer structure. However, higher molecular weight polymers were more sensitive to pH variation especially in alkaline media. Also, higher polymer concentration acted as driving force to decrease cloud point of samples and formation of aggregates that was more predominant for higher molecular weights at alkaline media. T cl of PDMAEMA chains decreased with increasing ionic strength even at low pH values for low molecular weight polymers. GRAPHICAL ABSTRACT: