Univ. Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France; Laboratório de Pesquisa em Petróleo - LAPET, Universidade Federal do Rio Grande do Norte, 59078970 - Natal, RN - Brazil.
Laboratório de Pesquisa em Petróleo - LAPET, Universidade Federal do Rio Grande do Norte, 59078970 - Natal, RN - Brazil.
Carbohydr Polym. 2018 Mar 15;184:108-117. doi: 10.1016/j.carbpol.2017.12.053. Epub 2017 Dec 24.
Graft copolymers based on carboxymethylcellulose (CMC) and thermosensitive polyetheramines (ethylene oxide/propylene oxide = 33/10 and 1/9) were prepared in water, at room temperature, by using a carbodiimide and N-hydroxysuccinimide as activators. SLS was applied to obtain M, A and R of CMC and its derivatives. Amide linkages were evidenced by FTIR and grafting percentage was determined by H NMR. TGA demonstrated that copolymers were thermally more stable than their precursors. DLS, UV-vis and rheological measurements revealed that properties were salt- and thermo-responsive and linked to the polysaccharide/polyetheramine ratio and the hydrophobicity of the graft. None of the copolymers showed cloud point temperature (Tcp) in water, but they turned turbid in saline media when heated. Copolymers exhibited thermothickening behaviour at 60 °C (>Tcp) in saline media. Below their Tcp, they showed the ability of keeping constant viscosity or even slight increase it, which was interpreted in terms of intermolecular hydrophobic associations.
基于羧甲基纤维素（CMC）和热敏型聚醚胺（氧化乙烯/氧化丙烯=33/10 和 1/9）的接枝共聚物在室温下于水中通过使用碳二亚胺和 N-羟基琥珀酰亚胺作为活化剂来制备。通过 SLS 获得 CMC 及其衍生物的 M、A 和 R。通过 FTIR 证实了酰胺键的存在，并且通过 H NMR 确定了接枝百分比。TGA 表明共聚物比其前体具有更高的热稳定性。DLS、UV-vis 和流变学测量表明，这些性质具有盐和温度响应性，并与多糖/聚醚胺的比例和接枝的疏水性有关。这些共聚物在水中均没有表现出浊点温度（Tcp），但在加热时在盐溶液中变得混浊。共聚物在盐溶液中在 60°C（>Tcp）下表现出热增稠行为。在低于其 Tcp 时，它们表现出保持恒定粘度甚至略微增加粘度的能力，这可以解释为分子间的疏水缔合。
