Boltorn®

Similar materials, hyperbranched polyesters based on bis-MPA and a polyol are now commercially available [11] from Perstorp AB under the trade name Boltorn [12], Figure 8.1. The average number of hydroxyl groups per molecule can be tailored between 8 and 64 and molecular weight can be varied between c. 2000 and 11 000. The co-polymerization of bis-MPA and a polyol core keeps the molecular weight distribution fairly low, typically below 2. 

Figure 8.1 A schematic representation of the hydroxy-functional hyperbranched polyester Boltorn H20, based on ethoxylated pentaerythritol and 2,2-bis(methylol)propionic acid [10]...

The use of aliphatic monomers for hyperbranched polyesters has been debated because aliphatic monomers are said to be prone to thermal degradation reactions such as decarboxylation, cyclization, or dehydration [77]. The only commercial hyperbranched polymer is a hydroxy-functional aliphatic polyester, Boltorn, available from Perstorp AB, Sweden. 

Parquette et al. reported on a disaccharide synthesis on a hyperbranched polyester support (Boltorn hyperbranched polymer) (16) (Fig. 7.9) [44]. This polymer was obtained in a one-step synthesis and offers low cost, high-loading capacities (8.8 mmol OH-groups g ), and the intermediates were soluble in most aprotic solvents. 

Scheme 7.4 Disaccharide synthesis using a hyperbranched polymer (Boltorn polymer) as a soluble support.

Figure 1. Schematics of Boltorn hyperbranched aliphatic esters. Insert shows the network formed by covalent linking of hyperbranched molecules with diisocyanate.

Figure 5. Stress-strain behavior of Boltorn H40/HDI networks.

Table I. Oxygen barrier characteristics of pure Boltorn H40 and H40/HDMI networks at 0% and 50% RH.

To avoid some limitations of PEGs, as for instance low loading, hyperbranched polyester such as Boltorn H40 and H50 have been successfully investigated in glycosylation reactions with 0-glycosyl trichloroacetimidates [121]. For simple mono- and disaccharide synthesis optimization of the reaction conditions led to practically quantitative transformations. 

Fig. 11 A fragment of a perfect Boltorn polymer and a schematic representation of the prepared dendrimers [114]...

Commercially avaUahle hyperhranched polymers possess in some cases low molecular weights and are usually less defined with broad molecular weight distributions. Examples are poly(ethylene imine) (BASF), Boltorn polyesters (Perstorp), polyglycerol (Hyperpolymers) and Hyhrane polyesteramides (DSM)... 

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. 

At an early stage, the addition of a core molecule By(y > 2) was explored (Scheme 24.1), mainly to provide a better control over the molar mass but also to control the resulting geometric shape [21]. When using a core molecule, the resultant products should no longer exhibit the focal unit A, though this will limit the molar mass build-up such that the molar mass will be controlled by the ratio ByiAB ,. The most prominent example of this is the polycondensation of 2,2-bis(hydroxymethyl)propionic acid in the presence of l,l,l-tris(hydroxymethyl)propane. In this case, control over the reaction is achieved by the successive addition of monomer portions this process is used for the industrial synthesis of Boltorn . However, the complete incorporation of the core molecule into each hb macromolecule, in aU molar mass fractions, is not trivial and cannot always be achieved. 

Figure 24.5 SEC-MALLS chromatograms and molar mass versus elution volume for Boltorn H40. (a) In dimethylacetamide (DMAc) for two different solution concentrations injected. (Scheme provided by E.

Figure 10.20 Schematic iiiustrations of in situ crosslinking of HBP (Boltorn H2004 ) in the PLA melt with the help of a polyanhydride (PA-18 (LV)) and related morphologies (up) as well as morphologies of tensile...

Fig. 2. Hyperbranched polyester based on bis-MPA and a polyol, commercially available from Perstorp AB (http //www.perstorp.com) under the trade name Boltorn.

Fig. 14. Hyperbranched resins have much shorter drying times than conventional resins (alkyd resin made from Boltorn). Reference alkyds and -B- dendritic alkyds.

Fig. 15. Ring-opening polymerization of s-caprolactone using Boltorn and stannous oc-tanoate as a macroinitiator (66).

This review is devoted to the description of synthetic strategies for glycodendrimers synthesis. Dendrimers can be classified into three categories carbohydrate-coated, carbohydrate-centered and carbohydrate-based dendrimer. In this paper we will focus on the third one, in which the core unit is originated from a monosaccharide. Compare to classical Pamam, Boltorn cores, carbohydrate units add much more three dimension information, coded in the chirality in almost each carbon. Various coupling chemistry have been developed and are presented here glycosylation, amide bound formation, and click chemistry (thiol-ene reaction, epoxide - thiol reaction). 

Domanska, U. and Zrfek-Tryznowska, Z. (2010) Measurements of mass-fraction activity coefficient at infinite dilution of aliphatic and aromatic hydrocarbons, thiophene, alcohols, water, ethers, and ketones in hyperbranched polymer, Boltorn H2004, using inverse gas chromatography. J. Chem. Thermodyn., 42, 363—370. 

Xiao and co-workers have constructed unimolecular micelles from the biocompatible hyperbranched polymer Boltorn , modified with poly(L-glutamate) and PEG chains... 

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