Polymerization alcohol

Under acidic conditions, furfuryl alcohol polymerizes to black polymers, which eventually become crosslinked and insoluble in the reaction medium. The reaction can be very violent and extreme care must be taken when furfuryl alcohol is mixed with any strong Lewis acid or Brn nstad acid. Copolymer resins are formed with phenoHc compounds, formaldehyde and/or other aldehydes. In dilute aqueous acid, the predominant reaction is a ring opening hydrolysis to form levulinic acid [123-76-2] (52). In acidic alcohoHc media, levulinic esters are formed. The mechanism for this unusual reaction in which the hydroxymethyl group of furfuryl alcohol is converted to the terminal methyl group of levulinic acid has recendy been elucidated (53). 

The chemistry of furfuryl alcohol polymerization has received much attention over the years. Several recent reviews have been written (5,6,54). Based on the accumulated data, furfuryl alcohol has to be considered a bifimctional monomer in the initial stage and its "normal" reactions give linear chains or oligomers containing essentially two repeating units (15,16) with (16) predominating. 

Equation 20 is the rate-controlling step. The reaction rate of the hydrophobes decreases in the order primary alcohols > phenols > carboxylic acids (84). With alkylphenols and carboxylates, buildup of polyadducts begins after the starting material has been completely converted to the monoadduct, reflecting the increased acid strengths of these hydrophobes over the alcohols. Polymerization continues until all ethylene oxide has reacted. Beyond formation of the monoadduct, reactivity is essentially independent of chain length. The effectiveness of ethoxylation catalysts increases with base strength. In practice, ratios of 0.005—0.05 1 mol of NaOH, KOH, or NaOCH to alcohol are frequendy used. 

Alcohol production, 13 768, 798 Alcohol sulfates, 2 19, 20 rat oral LD50 values, 8 445 Alcohol sulfation, 23 536-537 Alcohol testing, 12 96 Alcoholysis, 10 490, 491, 499, 503 18 519 in silicone chemistry, 22 554 in vinyl alcohol polymerization, 25 608-609... 

Batch saponification, in vinyl alcohol polymerization, 25 610 Batch scale up, pilot plant, 79 460 Batch sequencing and logic control,... 

Belt-conveyor scales, 26 244—245 Belt filter press, 25 913 Belt saponification, in vinyl alcohol polymerization, 25 609-610 Benard instability, 11 764 Benazepril hydrochloride, molecular formula and structure, 5 149t Benchmark dose and margin-of-exposure method, 25 244... 

Commercial hybrid materials, silicon-based, 73 538—540 Commercial hydrazines, physical properties of, 73 565t Commercial hydrolysis, in vinyl alcohol polymerization, 25 609, 612t Commercial immunoassays, for clinical applications, 74 140 Commercial inks, 74 320 Commercial laundering, detersive systems for, 8 413t... 

Continuous reforming operations, 25 166 Continuous salt mining, 22 806 Continuous saponification, 22 737—738, 741 in vinyl alcohol polymerization, 25 609-610... 

Ally I Type Alcohol, Polymerized. See under Polymerized Alcohols... 

Allyl Type Alcohols, Polymerized. See under Polymerized Alcohols Aliyiene(Propyne or Propine), CH3. C CH, mw 40.06- Gas, mp -102.7°, bp -23.2° SI sol in w, sol in ale eth. Its toxicity and fire Si expln hazards are discussed in Ref 3 It was reported that an expln occurred when an attempt was made to carry out the reaction HC C. CH2C1 + 2NH3 = NH4C1 +... 

J. Bilbao, M. Olazar, A. Romero, J.M. Arandes, Design and operation of a jet spouted bed reactor with continuous catalyst feed in the benzil alcohol polymerization, Ind. Eng. Chem. Res. 26 (1987) 1297-1304. 

The efficiency with which resin is formed from the weight of resin forming material taken up within the wood was calculated on the basis of one mole of water being lost for each mole of furfuryl alcohol polymerized (0.815) and all catalyst and water lost as vapor or from leaching subsequent to the final water soak. 

An adjunct to the understanding of this mechanism is the evidence obtained that polymerization of 2,5-bis(hydroxymethyl) furan produces no 2,2,-difuryl methane or higher homologues (35). Analysis by thin-layer chromatography shows such resin having greater than 95% difunctional components (terminal hydroxymethyl groups) as compared to less than 50% for the resin from a conventional furfuryl alcohol polymerization (35). 

Yeliseyeva et ai. (1976) studied the polymerization kinetics of polar acrylic monomers using ethyl acrylate. The dependence of the polymerization rate on the initiator concentration (ammonium persulfate) was examined at equal ionic strength in the presence of two emulsifiers, sodium dodecylsuDate and oxyethylaled (30) cetyl alcohol- Polymerization was carried out hi a dilatometer at 4S C, monomer-water phase ratio 1 9, and ammonium persulfate concentration 0.44-4.4 x 10 mol/dm. The obtained loagrithinic dependence is shown in Fig. 16. In each cases the... 

Rash pt 70 F open cup) 5 F closed cup) autoig-nition temp 7l3 F. 72.3% of the alcohol with 27.7% water forms a constant boiling mixture, bp at 87.5. Miscible with water, alcohol chloroform, ether, petr ether. Keep lightly closed. Upon storage for several years allyl alcohol polymerizes and a thick syrup is formed (insol in water, so] in chloroform) which on treatment with ether yields a brittle resin -oid mass Blicke. J. Am. Chem. Soc. 45, 1563 (1923) LDs0 orally in rats 64 mg/kg, Smyth, Carpenter J. Ind. Hyg. Tivcicot. 30, 63 (1948). 

Internal melt lubrication Metal stearates fatty amides, ester, acids, or alcohols polymeric agents Increased output Reduced melt viscosity and temperature Process energy savings and reduced torque Improved mold-filling Part-surface contamination possible (and reduced printability) Lower physical properties (or higher, depending on the processing aid)... 

Ozonides are reasonably stable in neutral environments, but they will decompose readily imder the influence of heat or various reducing agents to yield such chain scission products as aldehydes, ketones, acids, and alcohols. Polymeric peroxides may be formed initially from the carbonyl oxide, but these are unstable and will eventually decompose to yield chain scission products. 

A CO2/N2 selectivity of around 1,800 for cross-linked polyvinyl alcohol polymeric membranes containing amine functionality in the form of 2-aminoisobutyric acid-potassium salt (mobile amine carrier) and poly (allylamine) (fixed carrier), at 110 °C was reported by Zou et al. [13], The main differences between this study and that reported by Zou et al. [13] are as follows (1) they used two types of amine carriers while suggesting that the mobile carriers connibuted more to the CO2 flux than the fixed carriers as opposed to APTS-modified membranes where the carriers were fixed [attached to the pore walls], (2) in their study, water was used both on the feed and permeate side, enhancing the reaction rate of CO2 with... 

Of some interest is the fact that many solvents act as chain transfer agents and are used to control the molar mass of the product. Also Kalb et al. [456] mentioned the possibility of adding telogens (chain-terminating agents) to reduce the intrinsic viscosity of the product. Fie studied the effect using methanol or other alcohols. Polymerization with solvents such as toluene [452] and benzene [456] yielded a low-molar-mass polymer, and the conversion did not increase over 17% even when the pressure was raised to 9 x 10 Pa. 

The first product of furfuryl alcohol polymerization is thought to be a linear polymer, formed as follows ... 

---