Pluronic® series

In our work, we calculate the equilibrium moisture from the dry and saturated mass of samples. The method was described by Thomson. We use more hydrophilic polyols, for example, hydrophiUc polyurethanes and polyethylene glycol homopolymers are used. More commonly, however, we will be using polyols from the Pluronic series of block copolymers discussed in Chapter 2. 

Of the triblock copolymers, the Pluronic series are the most popular. According to the product information by BASF, the nomenclature of Pluronic surfactants can be described based on the molecular weight ranges of the hydrophobe propylene oxide (PO) against the weight-percent of the hydrophile ethylene oxide (EO) present in each molecule. The letter-number combinations can be... 

Figure 6.36 The Pluronic grid for (a) the poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) [Pluronic] series and (b) the poly(oxypropylene)-poly(oxyethylene)-poly(oxypropylene) [Pluronic R] series of block copolymers.

By combining measurements of the repeat spacing from XRD measurements and pore diameters from one of the above techniques, or from modelling of the intensities of XRD peaks, the wall thickness of these materials can be calculated. The wall thicknesses of materials templated using neutral surfactants with EO headgroups, in particular the triblock copolymers such as the Pluronic series are much greater than those templated using small molecule cationic or anionic surfactants. Early measurements of the wall thicknesses of MCM-41 and MCM-48 found a width of about 8 A, equivalent to about two layers of tetrahedral SiOi units. ... 

Urethane acrylate ofigomer, rheology modifier resin, 382 Pluronic (Series)... 

The copolymers are another family of non UV-absorbing nonionic surfectants, in which the hydrophilic chain is an ethylene oxide polymer, and the hydrophobic chain is a propylene oxide polymer. The two polymers can be connected in one or several points. For example, the Pluronic series from the Wyandotte Chemicals Corporation are block copolymers with the general formula ... 

Table 2.3 Structure and Commercial Denomination of the Block Copolymer Nonionic Surfactants of the Pluronic Series ...

Mortensen and Brown (1993) investigated the conditions for formation of gels formed by spherical or rod-like micelles in a series of Pluronic PEO, PPO PEOm... 

The main disadvantage of the use of -y-irradiation is that the drug has to be incorporated at the primary emulsification step and is therefore exposed to the 7-irradiation. To overcome this difficulty Law et al (44) have synthesised a series of acryolyl derivatives of certain poloxamer surfactants. Bredimas et al (45) have shown that it is possible to stabilise an unstable o/w emulsion by polymerisation of diacrylate surfactant molecules in surface crosslinking reactions. We have confirmed this (44) and have succeeded in stabilizing w/o/w emulsions, the primary emulsion comprising isopropyl myristate with 5% Span 80 and 0.9% of the diacryloyl derivative of Pluronic L44 in the aqueous phase (0 =... 

To illustrate the capabilities of the system shown in Fig. 16.12, we present new, previously unpublished results from our laboratory. In Fig. 16.13, we illustrate results for three fluorescent probe molecules (pyrene, DCM [4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran], and PRODAN [6-propionyl-2-(/V,/V-dimethylamino)naphthalene]) that were doped within a series of PFFA/Pluronic P104 BP blends. In the initial experiments, 16 BP formulations were prepared manually using micropipettes, while subsequent experiments utilized the ALHS to prepare 21 BP formulations. These formulations were spun cast into thin films employing quartz microscope slides as substrates. To characterize the local microenvironment surrounding each probe within a given formulation, steady-state fluorescence measurements using a conventional spectrofluorometer were performed. 

Pluronic [BASF], TM for a nonionic series of 28 related difunctional block-polymers terminating in primary hydroxyl groups with molecular weights ranging from 1,000 to more than 15,000. They are polyoxyalkylene derivatives of propylene glycol. Available in liquid, paste, flake powder, and cast-solid forms. 

Inhibition of Lipid Absorption - Agents which decrease the absorption of dietary lipids specifically by inhibiting pancreatic lipase may be suitable for the treatment of obesity. The reduced rate of lipid absorption produced by fenfluramine in rats is probably due to an inhibition of pancreatic lipase. The structural features of a series of phenethylamines, including fenfluramine, required for lipase inhibition have been described using partially purified rat and human pancreatic lipase. Pluronic L-101, a hydrophobic surfactant is a potent inhibitor of pancreatic lipase vitro and reduces body weight gain and carcass lipid after chronic administration to rats. Fecal excretion of dietary lipid is enhanced by Pluronic L-101, thus supporting its action as a lipase inhibitor. 

Poly( ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) is another kind of thermosensitive polymer, known as poloxamer (25,26). Poloxamers are a series of surfactant polymers that are commercially available. Among these, poloxamer 407 (Pluronic F127) has been of particular interest, since this amphiphilic triblock copolymer can form micelles at low concentration in water and, with increasing concentration, can form a hydrogel at body temperature via... 

Ionic detergents, such as cetyltrimethylammonium bromide or sodium dodecyl sulfate, give pore sizes between 2 and 4 nm, whereas nonionic surfactants such as the Pluronics and the Tween surfactant series (ethoxylated sorbitan esters) give materials with larger pores (around 10 nm) and thicker walls (Table 18.1). 

Formulation can be specific to the crude oil emulsions such as was shown for Buchan crade by Mohammed et al. (67). They used nonionic surfactants from the Pluronic (PE) and Tetronic series, which differed basically in die degree of EO/POcopolymers added to straight chains or branches. In combination with wetting agents and octy- or... 

Meroxapol 105-, Meroxapol 777 Meroxapol 172-, Meroxapol 774 Meroxapol 252-, Meroxapol 254 Meroxapol 258 Meroxapol 311 Nopcowax 22-DS Pluronic 10R5 Pluronic 17R4 Pluronic 25R4 Polyacrylamide binder, iatex modification Polyvinyl methyl ether binder, iatex paints Alpha-Cel Methocel 310 Series Methocel E15LV Methocel J5MS binder, ieather finishes Hycar 2671... 

HLB calculated from glc relative retention ratios except tor PLURONIC R series estimated ranges Not compielety soluble tns Insoluble... 

Pluronic is a generic name for a series of block copolymers composed of different ratios of more hydrophobic propylene oxide (PPO) monomers flanked by more hydrophilic ethylene oxide (PEO) monomers. Several commercially available analogs of Pluronics are shown in Figure 28.6 with the weight fraction of the hydrophilic PEO units ranging from 0.1 to 0.8. 

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