Stabilized rosin

Rosin ester resins are used extensively in pressure-sensitive adhesives as tackifiers. The adhesive is formulated by blending the resin with a polymer in solution or as aqueous emulsions. Typical compositions may contain about 50% resin. The glycerol or pentaerythritol esters of stabilized rosins are often used because they are stable on aging. 

The effects of storage time of an unstabilized and a stabilized rosin ester tackifier on the properties of an EVA HMA are illustrated in Figs. 15-17. Significant effects on the initial color of the EVA HMA (Fig. 15) are observed when using an unstabilized tackifier. An increased level of hydroperoxides is also noted. In this situation, the addition of an antioxidant to the HMA will not correct the problem. However, the addition of an antioxidant to the HMA may reduce further discoloration during compounding or end-use applications. 

Glycerol Ester of Highly Stabilized Rosin Pentaerythr itol Ester of Stabilized Rosin Pentaerythritol Ester of Highly Stabilized Rosin Poly a-Pinene Poly (vinyl cyclohexane)... 

Studies of polymers dissolved in various oils indicate general agreement, with the volume fraction exponent reported to be 2 to 2.3 (5,6). In a recent study, W.W. Graessley and co-workers (7) reported exponents of 2.22 and 2.26 for polybutadiene and hydrogenated polybutadiene in various diluents. G. Kraus and K.W. Rollmann (8) reported on the only study of resins as the polymer diluent. Using a styrene-isoprene-styrene block copolymer, they found exponents of 2.28 for the glycerin ester of stabilized rosin and 2.62 for a C -stream resin. Plateau modulus was identified as G in the rubbery plateau where tan 6 was a minimum in a temperature scan of the systems. 

Chem. Descrip. Noncryslallizing stabilized rosin CAS 8050-09-7 EINECS/ELINCS 232-475-7... 

Chem. Descrip. Stabilized rosin sol n. in Rule 66/3 mineral spirits... 

Fortified rosin can also be converted to high free-rosin emulsions by using various stabilizers. Typically, these are 35% soHds emulsions, which exhibit exceUent stabiHty in relation to storage and mechanical action, such as is found in transfer pumps. Generally, fortified rosin emulsions are more efficient sizes than their soap-based Hquid or paste counterparts. 

In disproportionation, rosin is heated over a catalyst to transfer hydrogen, yielding dehydro (5) and dihydro (8) resin acids. The dehydro acids are stabilized by the aromatic ring the dihydro acids contain only an isolated double bond in place of the less stable conjugated double bonds. 

Rosin ester resins are used as modifiers in the formulation of chewing gum. The rosin derivative modifies the physical properties of the polymer used, providing the desired masticatory properties. The glycerol ester of hydrogenated rosin is the predominant choice, because stabilized materials have improved aging resistance, which extends the shelf life of the gum. 

The most commonly used emulsifiers are sodium, potassium, or ammonium salts of oleic acid, stearic acid, or rosin acids, or disproportionate rosin acids, either singly or in mixture. An aLkylsulfate or aLkylarenesulfonate can also be used or be present as a stabilizer. A useful stabilizer of this class is the condensation product of formaldehyde with the sodium salt of P-naphthalenesulfonic acid. AH these primary emulsifiers and stabilizers are anionic and on adsorption they confer a negative charge to the polymer particles. Latices stabilized with cationic or nonionic surfactants have been developed for special apphcations. Despite the high concentration of emulsifiers in most synthetic latices, only a small proportion is present in the aqueous phase nearly all of it is adsorbed on the polymer particles. 

Carbon tetrachloride [56-23-5] (tetrachloromethane), CCl, at ordinary temperature and pressure is a heavy, colorless Hquid with a characteristic nonirritant odor it is nonflammable. Carbon tetrachloride contains 92 wt % chlorine. When in contact with a flame or very hot surface, the vapor decomposes to give toxic products, such as phosgene. It is the most toxic of the chloromethanes and the most unstable upon thermal oxidation. The commercial product frequendy contains added stabilizers. Carbon tetrachloride is miscible with many common organic Hquids and is a powerhil solvent for asphalt, benzyl resin (polymerized benzyl chloride), bitumens, chlorinated mbber, ethylceUulose, fats, gums, rosin, and waxes. 

On the other hand, not only initial colour but colour change (discolouration) of the resin under UV light and heat is important. Colour retention of a resin is related to the chemical stability and increases as the degree of non-aromatic conjugated unsaturation of the resin molecule decreases. Thus, for rosins a high level of abietic-type resin acids lead to relatively unstable resins. Hydrogenation and disproportionation as well as esterification provide improved stability and colour retention to rosins. 

For rosins and rosin esters, the produets having high aeid numbers are the most susceptible to oxidation and have inferior viscosity stability and colour stability in adhesive formulations. Thus, when stability properties are essential in adhesives, rosin esters rather than high aeid number rosins are used. However, the high acid number resins are polar and display better adhesion to polar elastomers and polymeric surfaces. 

BW Erickson, RB Merrifield. Acid stability of benzylic protecting groups used in solid-phase peptide synthesis. Rearrangement of O-benzyltyrosine to 3-benzylty-rosine. J Am Chem Soc 95, 3750, 1970. 

Inert Simulants for High Explosives. In certain physical tests on weapons explosives, eg the effects of humidity and temp cycling on the dimensional stability of the weapon, it is desirable to simulate the explosive filler by an inert filler. Many such inert simulants have been proposed and tested (Refs 1, 2 3). Simulants for Comp B TNT have been patented (Ref 4). The simulant for Comp B consists of a mixt of 30% of 1,2 hydroxystearic acid, 5% wood rosin 65% dead-burned gypsum. The simulant for TNT is a 40/60 mixt of hydroxystearic acid dead-burned gypsum... 

The principal constituents of rosin (qv) are abietic and related acids. Tall oil (qv) is a mixture of unsaturated fatty and alicydic acids of the abietic family. Refined tall oil may be high in rosin acids or unsaturated acids, depending on the refining process. Ethoxylates of rosin acids, eg, dehydro abietic acid, are similar to fatty acid ethoxylates in surfactant properties and manufacture, except for their stability to hydrolysis. No noticeable decomposition is observed when a rosin ester of this type is boiled for 15 min in 10% sulfuric acid or 25% sodium hydroxide (90). Steric hindrance of the carboxylate group associated with the alicyclic moiety has been suggested as the cause of this unexpectedly great hydrolytic stability. 

Such substances as vaseline (added to nitroglycerine powders of the cordite type), castor oil and rosin are also capable of stabilizing powder. 

G-L. Griffith, G.A. Lyte F.B. Wells, USP 3366053(1968) CA 68, 70809(1968) [Free-flowing, inorg nitrate based expl mixts sensitized to initiation by incorporation of 1—4% powd Al and 1—6% water, are described. Expl sensitizers, such.as NS (preferred), NG, TNT, PETN, RDX, Pentolite or Comp B 5-7, carbonaceous fuels 0.4, stabilizers-antacids (such as CaCO a or MgO) up to 0.4, and materials (such as rosin, metallic resinates, hexamine, waxes or mineral oil) 0.4% could also be present. A mixt listed in CA contg AN 70.68, NaN03 8.91, Al powd 1.57, NS... 

The explosibility of AN with approx 7% rosin was investigated by Hopper (Ref 9), who found that rosin increased the sen si tiv- ity to initiation and rendered the mixt less hygroscopic. The mixt was also satisfactory with respect to stability, brisance and impact sensitiviry, being unaffected in the rifle bullet and pendulum friction tests. Marshall (Ref 23) and Banik(Ref 26) studied the explosibility of Amer FGAN contg 1% petrolatum and 5% kaolin in comparison with Brit FGAN contg... 

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