Hyperbranched polyols

Figure 11.8 Zimm and Guinier plots of G4 PAMAM dendrimer and G5 hyperbranched polyol. The dendrimer fits Guinier (spherical) and the hyperbranched fits Zimm (Gaussian)...

This research was primarily funded by the Office of Naval Research, Grant No NOOO14-04-1-0703. The authors are also grateful to the National Science Foundation (MRSEC Award DMR 02138830). The authors would like to thank Perstorp Perstorp Specialty Chemicals AB for providing Boltom hyperbranched polyols. The authors thank Dr. Robert Stote for biodegradation measurements at Natick. In addition the authors thank the Polymer Performance, Degradation and Material Selection ACS Symposium Series organizers for the opportunity to present our work and for the preparation of this book. 

Fig. 17 a The chemical structure of the pyridyl-functionalized PANAM 35 and the schematic of the smectic phase which is formed upon complexation with 3-cholesteryl-oxycarbonylpropanoic acid 34 b The chemical structure of the pyridyl-functionalized hyperbranched polyol 36 and schematic of the smectic phase which is formed upon complexation with 34... 

Highly hyperbranched polyolic structures are obtained by the polyaddition of an hydroxy epoxidic compound, such as glycidol, to a polyol in cationic [1] or anionic catalysis [11-... 

A much more symmetric structure of hyperbranched polyols is obtained by using as monomer, an oxetane containing an hydroxyl group (produced industrially by Perstorp), 3-ethyl-3-methylol-oxetane, formally resulting from the intramolecular etherification of TMP (Figure 19.4). 

A variety of poly/dihydric oils are used for the preparation of glyddyl ether-type epoxy resins. These include bisphenols, namely bisphenol-A (BPA), bisphenol-F (BPF), bisphenol-S (BPS) and bisphenol-H (BPH) and so on. Other aromatic diols and polyols such as phenolic resin, MF resins and hyperbranched polyol may also be used in the preparation of vegetable oil-based epoxy resins. Bisphenol-A (2,2-bis(4-hydroxyphenyl)propane) is one of the most widely used aromatic diols for the synthesis of epoxy resin. The resins are commonly used as lacquers for coated metal products such as food cans, bottle tops and water pipes. There are also reports on the use of bisphenol-S (BPS) (bis(4-hydroxyphenyl) sulphone), in the synthesis of epoxy resin. The advantages of resistance to deformation by heat and improvement of thermal stability were observed for such epoxy resins. The presence of sulphone group (BPS-based epoxy resin) in the epoxy resin exhibits better gel time than BPA-based epoxy. Another important diol, namely bis(4-hydroxydiphenyl)methane or bisphenol-F (BPF) is used for the synthesis of low viscosity epoxy resins. BPF generally comprises several isomers such as bis(2-hydroxylphenyl)methane (i.e. ortho-ortho isomer), bis(4-hydroxylphenyl)methane (i.e. para-para isomer) and... 

Some hyperbranched polyurethanes with different compositions based on Mesua ferrea L. seed oil, sunflower oil, and so on, have been prepared by using monoglyceride and glycerol or monoglyceride with hyperbranched polyol. Hyperbranched polyurethanes have been prepared from soybean oil-modified hyperbranched polyol obtained via epoxidation and hydrofor-mylation. Castor oil-based hyperbranched polyurethanes have been synthesised using castor oil as the B3 monomer in an A2 -1- B3 approach. The A2 monomer, -NCO terminated pre-polymer was obtained by reacting MDI with PCL. The urethane reaction was carried out at ca. 110°C in the... 

Preparation of a hyperbranched polyurethane using a hyperbranched polyol core. 

Cationic UV curing Effect of the hyperbranched polyol as flexibilizer and chain-transfer agent on cationic UV curing [57]... 

Hong, X., Chen. Q., Zhang. Y, and Liu, G. Synthesis and Characterization of a Hyperbranched Polyol with Long Flexible Chains and Its Application in Cationic LTV Curing. Journal of Applied Polymer Science, 77, 1353-1356 (2000). 

In summary, anionic polymerization techniques are by far the most common approach in the synthesis of well-defined hyperbranched polymers by ROP at present, especially in the field of hyperbranched polyols. Numerous research groups are currently engaged in the preparation, modification, and characterization of such polymers for a wide variety of applications, ranging from biomedicine, advanced coatings, and rheological modifiers to novel catalyst supports. 

The best-performing composite was prepared with H30 at 8 wt. % montmorillonite. The ratio 1.83 indicated the largest enhancement of modulus relative to the pure polyurethane for the 8 wt.% containing composites. The percent elongation to failure increased from 236 15% for the pure polymer to 374 32% for the 8% loaded polyurethane-montmorillonite composite. These hyperbranched polyols provide a significant enhancement of mechanical properties for the polyurethane cure chemistry evaluated with Cloisite 30B as the dispersed-phase reinforcement. Additional work needs to be done with Cloisite 30B present during the cure to ascertain if further benefits to mechanical properties are derived from the reaction of the isocyanate with the primary hydroxyls on the quat exchanged onto the montmorillonite. 

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