Polymeric and non-crosslinked acid self-thickening agent based on hydrophobically associating water-soluble polymer during the acid rock reaction

Different from traditional crosslinked polymer diverting agents, a polymeric and non-crosslinked acid self-thickening agent (ZPAM) based on hydrophobically associating water-soluble polymer of acrylamide (AM), [2-(methacryloyloxy)ethyl]trimethylammonium chloride (DMC) and N,N′-dimethyl octadecyl allyl ammonium chloride (DOAC) was synthesized. The apparent viscosity variation of ZPAM acid solutions in acid rock reaction and rheological properties of ZPAM spent acid solutions were studied. Results showed that ZPAM acid solutions demonstrated good uninterruptedly thickening ability from low apparent viscosity to high apparent viscosity during the acid rock reaction. Meanwhile, ZPAM spent acid solutions showed good shear resistance, viscoelasticity and high temperature resistance. The thickening mechanism of ZPAM acid solutions during the acid rock reaction was explained by apparent viscosity change, rheological properties of simulative ZPAM acid solutions, and ZPAM aqueous solutions with different concentrations of CaCl₂. The results showed increasing calcium chloride concentration enhanced the hydrophobic association strength of the thickener solution, resulting in increasing solution viscosity, in other words, the self-thickening agent showed excellent salt resistance and acid resistance. In addition, the change of association strength of ZPAM acid solutions during the acid rock reaction was further confirmed via environmental scanning electron micrographs and UV spectrum. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47907.     

A Self-Thickening and Self-Strengthening Strategy for 3D Printing High-Strength and Antiswelling Supramolecular Polymer Hydrogels as Meniscus Substitutes

3D printing of high-strength and antiswelling hydrogel-based load-bearing soft tissue scaffolds with similar geometric shape to natural tissues remains a great challenge owing to insurmountable trade-off between strength and printability. Herein, capitalizing on the concentration-dependent H-bonding-strengthened mechanism of supramolecular poly(N-acryloyl glycinamide) (PNAGA) hydrogel, a self-thickening and self-strengthening strategy, that is, loading the concentrated NAGA monomer into the thermoreversible low-strength PNAGA hydrogel is proposed to directly 3D printing latently H-bonding-reinforced hydrogels. The low-strength PNAGA serves to thicken the concentrated NAGA monomer, affording an appropriate viscosity for thermal-assisted extrusion 3D printing of soft PNAGA hydrogels bearing NAGA monomer and initiator, which are further polymerized to eventually generate high-strength and antiswelling hydrogels, due to the reconstruction of strong H-bonding interactions from postcompensatory PNAGA. Diverse polymer hydrogels can be printed with self-thickened corresponding monomer inks. Further, the self-thickened high-strength PNAGA hydrogel is printed into a meniscus, which is implanted in rabbit's knee as a substitute with in vivo outcome showing an appealing ability to efficiently alleviate the cartilage surface wear. The self-thickening strategy is applicable to directly printing a variety of polymer-hydrogel-based tissue engineering scaffolds without sacrificing mechanical strength, thus circumventing problems of printing high-strength hydrogels and facilitating their application scope.     

丙烯酸酯及其共聚乳液自增稠等特性分析

本文分析了丙烯酸、甲基丙烯酸在丙烯酸丁酯、甲基丙烯酸甲酯共聚乳液中影响，尤其自增稠特性。     

自增稠多元丙烯酸酯共聚乳液的合成

以丙烯酸、丙烯酸酯以及N-羟甲基丙烯酰胺为原料,OP-10和K12为复合乳化剂,用半连续乳液聚 合工艺合成了自增稠多元丙烯酸酯共聚乳液。研究了引发剂用量、乳化剂用量以及聚合温度等因素对丙烯酸 酯共聚乳液性能的影响。     

月桂酰肌氨酸钠自增稠体系的研究

研究了月桂酰肌氨酸钠(LS)与非离子型、阴离子型以及两性离子型表面活性剂的复配体系。通过改变表面活性剂用量、配比等参数,发现对于二元复配体系,少量烷基糖苷(APG)即可实现协同增稠;而在三元复配体系中,配比对体系黏度影响极大,其中LS、椰油酰胺丙基甜菜碱(CAB)和APG复配能实现较好的自增稠效果。当在复配体系中CAB质量不低于LS时,复配体系黏度≥3 000 mPa?s,市场上流行的无硅油无硫酸盐类洗发产品可以借鉴此类自增稠方案。     

丙烯酸酯及其共聚乳液自增稠等特性分析

本文分析了丙烯酸，甲基丙烯酸在丙烯酸丁酯，甲基丙烯酸甲酯共聚乳液中的影响，尤其自增稠特性。