The synthesis and the bulk rheological properties of the highly-branched block polyethers

Abstract

Several kinds of highly branched block polyethers were synthesized via anion ring opening poly merization of propylene oxide (PO) and ethylene oxide (EO), using phenol amine resin (PA) as the initiator. The rheological properties determined by rotational rheometer all followed the regular rules of polymer systems: under a certain conditions, the bulk polyethers were pseudoplastic and non Newtonian fluid, and with the increasing of the shear rate and temperature, the apparent viscosity of the block copolymers were reduced. In addition, modulus determination showed that such polyether molecules presented preferable viscosity com pared to the elasticity, meanwhile, storage modulus, loss modulus and compound viscosity all decreased with the increasing of temperature. Storage modulus and loss modulus increased along with the scanning frequency increasing. But compared with the same kind of linear polymers, the significant difference was the low melt vis cosity, which attributed to the special three dimension space structure hindering the entanglement of chains. Furthermore, the rheological properties among the several block polyethers showed differences obviously. In other words, the number of block and the content of EO all have a significant effect on the rheological proper ties, specifically, the modulus will increase with the increasing of the block number and the EO content.

High‐performance thermosets with tailored properties derived frommulti‐armstared vanillin and carbon fiber composites

“…The higher viscosity of DGEBA is due to hydrogen bonding which is why increasing the temperature slightly to 50°C reduces its viscosity sharply (the DGEBA contains oligomers with secondary hydroxyl groups). As temperature raised, the activity of molecular chain segments achieved enhancement, and the free volume became larger, which weaken the molecular interactions and also the decreasing entanglement density further leaded to the decrease of the flow resistance 44,45 . The significantly reduced viscosity of HPVIGEP was consistent with our original design goal of multi‐arm star molecular structure.…”

“…As temperature raised, the activity of molecular chain segments achieved enhancement, and the free volume became larger, which weaken the molecular interactions and also the decreasing entanglement density further leaded to the decrease of the flow resistance. 44,45 The significantly reduced viscosity of HPVIGEP was consistent with our original design goal of multi-arm star molecular structure.…”

Effect of Different Ethylene Oxide Addition Numbers on the Performance of Polyoxyethylene Tallow Amine as a Pesticide Emulsifier

“…The reason for this result may be the small molecular weight of POEA relative to that of the high polymer. Yang et al 32 showed that the increase in the number of blocks and the EO content significantly affects the polyether's rheological performances and viscosity. Polyether viscosity increases with an increase of EO content.…”

Synthesis and Study of a New Type of Fluorinated Polyether Demulsifier for Heavy Oil Emulsion Demulsification

“…The polyether demulsifier performs well in enhancing the demulsification of the IAA-stabilized (interfacially active asphaltenes) emulsion, achieving complete water removal of the emulsions in 30 min at 60 °C and 400 ppm . Polyether demulsifiers can be divided into amines, alcohols, alkyl phenol resins, phenolamine resins, and hydrogen-containing silicone oils according to different initiators. , Poly­(propylene oxide)–poly­(ethylene oxide) and poly­(propylene oxide)–poly­(ethylene oxide)–poly­(propylene oxide) (PPO–PEO and PPO–PEO–PPO, respectively) block polyethers have good compatibility, mainly through the polymerization reaction of the starting agent and propylene oxide and ethylene oxide, which played an important role in crude oil demulsification, emulsification cleaning, sewage treatment, and other areas. , The properties of block polyether surfactants are closely related to the structure of the initiator . Linear, multibranched, dendriform polymers can be synthesized according to the amount and location of active hydrogen in the initiator. , …”

“…32,33 The properties of block polyether surfactants are closely related to the structure of the initiator. 34 Linear, multibranched, dendriform polymers can be synthesized according to the amount and location of active hydrogen in the initiator. 35,36 Fluorinated polyether demulsifier is one of the most important special surfactants and has the highest activity.…”