Epoxy resin hyperbranched polymers

Core-shell structures (Fig. 8.7) have also been suggested as a method of toughening epoxy resin formulations. The polymeric shell, which surrounds an elastomeric core, provides good adhesion to the epoxy matrix. Hyperbranched polymers with hydroxyl... 

Jin Jin, F.-L., Park, S.-J. Thermal properties and toughness performance of hyperbranched-polyi-mide-modified epoxy resins. J. Polym. Sci. Part B Polym. Phys. 44 (2006) 3348-3356. 

Ratiia D, Becker O, Krishnainurthy R, Simon G P and Varley R J (2003) Nanocomposites based on a combination of epoxy resin, hyperbranched epoxy and a layered silicate. Polymer 44 7449-7457. 

The use of epoxidized hyperbranched polyesters as toughening additives in carbon-fiber reinforced epoxy composites has been demonstrated (Boogh et al., 1995). Since a hyperbranched resin has a substantially lower viscosity and much shorter drying time than a conventional (less branched) resin of comparable molecular weight, hyperbranched polymers have been used as the base for various coating resins (Pettersen and Sorensen, 1994). 

Wu Wu, H., Xu, J., Liu, Y., Heiden, P. Investigation of readily processable thermoplastic-toughened thermosets. V. Epoxy resin toughened with hyperbranched polyester. J. Appl. Polym. Sci. 72 (1999) 151-163. 

Var Varley, R. J., Tian, W. Toughening of an epoxy anhydride resin system using an epoxidized hyperbranched polymer. Polym. Intern. 53 (2004) 69-77. 

Xu Xu, G., Shi, W. F., Gong, M., Yu, F., Feng, J. P. Curing behavior and toughening performance of epoxy resins containing hyperbranched polyester. Polym. Adv. Technol. 15 (2004) 639-644. 

Qie Chen, S. F., Zhang, D. H., Jiang, S. B., Jia, D. M. Preparation of hyperbranched epoxy resin containing nitrogen heterocycle and its toughened and reinforced composites. J. Appl. Polym. Sci. 123 (2012) 3261-3269. 

Toughened epoxy resins and epoxy nanocomposite systems were synthesized using DGEBA resin, diethylene famine hardener, octadecylammonium modified montmorillonite and epoxy functional dendritic hyperbranched polymer (Boltorn El, Perstorp Spedahty Chemicals, Sweden) with an epoxy equivalent weight of 875 g/eq and a molecular weight of 10500 g/mol. 

A large variety of hyperbranched polymers with acrylate, vinyl ether, allyl ether, or epoxy functions were studied as multifunctional cross-linkers in coatings and in thermosets, using thermal as well as UV curing methods Clearly, polyesters are most prominent in the field, with the Perstorp Boltom products leading in technical studies. The commercialized poly(esteramide)s from DSM, sold under the trade name Hybrane polyethylenimines from BASF AG, available under the trade name TupasoF and poly(urethane)s (PUs) and polyesters developed by BASF are examples for hyperbranched polymers suited for coatings and resin products. 

H. Deka and N. Karak, Shape-memory property and characterization of epoxy resin modified Mesua ferrea L. seed oii based hyperbranched polyurethane , J Appl Polym Sci, 2010,116,106-15. 

Boogh, L, Pettersson, B. and Manson, J. A. E. Dendritic hyperbranched polymers as tougheners for epoxy resins. Polymer (1999). 

BMI resins were modified with a wide range of other polymers in order to achieve improved properties. Toughened BMIs may be obtained by using polyetherketones (Han et al. 2009), while enhanced processing characteristics and low dielectric losses may be achieved for BMI by modification with allyl phenyl compounds, allyl epoxy resins, and epoxy acrylate resins (Liang et al. 2007). Flame retardancy was accomplished by modifying BMIs with fully end-capped hyperbranched polysilox-ane (Zhuo et al. 2011a). 

Chen X, Jiao C, Li S, Sun J (2011) Flame retardant epoxy resins from bisphenol-A epoxy cured with hyperbranched polyphosphate ester. J Polym Res 18 2229-2237... 

Huang P, Gu A, Liang G, Yuan L (2012) Synthesis of epoxy-functionalized hyperbranched poly(phenylene oxide) and its modification of cyanate ester resin. J Appl Polym Sci 123 2351-2359... 

These hyperbranched resins showed excellent adhesion, gloss, flexibility, and formability. The viscosities of epoxy functionalised polyester based coating mixtures with vernolic acid were also heavily influenced by the presence of the reactive diluent, from pure hyperbranched epoxy functionalised polymer with a viscosity of 4100 mPa s, to a formulation containing 30 wt% methyl ester of vernolic acid with a viscosity of 460 mPa... 

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