Polyformals containing

Polyformals containing secondary allylic and benzylic groups undergo complete acidolytic decomposition to volatile products such as an aromatic com-... 

Telechelic aromatic-aliphatic polyformals containing only primary alcohol chain ends can be conveniently synthesized from a bisphenol and an a,ft>-bis(chloromethoxy)alkane in the presence of a phase transfer catalyst as outlined in Scheme 66. This is in spite of some competing side reactions that are discussed elsewhere. ... 

Elemental analyses of the polyformals agreed with or were reasonably close to the calculated values therefore, the polymers contained substantially no poly-(methylene oxide) in the chains. Since excess formaldehyde was used in preparing the prepolymers, presumably their chains were terminated with hydroxymethyl groups. Both water and formaldehyde must then be eliminated during the buildup of polymers ... 

Effective catalysts for preparing the polyformals were p-toluenesulfonic acid, camphorsulfonic acid, methanedisulfonic acid, and perchloric acid. Various other acidic compounds were evaluated as catalysts with tetramethylcyclobutanediol. In these experiments, 0.5 to 1.0 gram of acidic compound per mole of tetramethylcyclobutanediol was normally added. If insufficient water was obtained, more catalyst was added. If the prepolymer was obtained but an appreciable amount of brown color was present, less catalyst was then used. Compounds which did not catalyze the reaction (no water obtained) were phosphoric acid, zinc chloride, trifluoroacetic acid, and heptafluorobutyric acid. Incomplete reactions (insufficient water) took place with concentrated hydrochloric acid, concentrated nitric acid, zinc fluoroborate, or Amberlite IRC-50 ion exchange resin as catalyst. A prepolymer was obtained when boron trifluoride etherate was used, but buildup did not take place in the solid phase (catalyst probably too volatile). Brown or speckled-brown polymers (after solid-phase buildup) were obtained with catalysts containing sulfonic acid groups (benzenesulfonic, dodecylbenzenesulfonic, sulfo-acetic, methanetrisulfonic, sulfuric, p-toluenesulfonic, camphorsulfonic, and methanedisulfonic acids). To obtain white polymers from tetramethylcyclobutanediol it was necessary to treat the solvent and prepolymer reaction mixture as previously described. (White polyformals were obtained from the other diols without this treatment.)... 

In addition, the formal unit itself offers a new opportunity for monitoring chain motion relative to the polycarbonates since the carbonate unit contains no protons. The spin-lattice relaxation times, T s of all protons and all carbons with directly bonded protons are reported for the polyformal. Also the carbon and proton Tj s are measured at two different Larmor frequencies to expand the frequency range covered by the study. 

The synthesis of aliphatic polyformals (X) been known for many years and is relatively straightforward. As shown in equation 1, aliphatic diols can be reacted directly with formaldehyde or dialkyl formals to produce these polymers. The principal complication of the reaction occurs when the diol used contains 2, 3 or 4 carbon atoms in which case the formation of the cyclic formal is favored. Musser and Jackson have more... 

A sample of containing <1% cyclics was injection molded at ca 410 F to give colorless, transparent parts whose preliminary properties were determined (see Table 3). For purpose of comparison, properties are also reported for a sample of BPA polycarbonate. The polyformal of BPA has a lower Tg and notched Izod impact than the corresponding polycarbonate. 

Preliminary information on new aromatic polyformals based on other bisphenols is contained in Table 7. Most of these materials have been made only once and no extensive characterization of the polymers has been made. None of these polyformals were examined for cyclic oligomers. Where possible, the T for the corresponding polycarbonate is also given. All polymerizations were run in NMP/ CH9CI9 mixtures except when the bisphenol contained an electron 0... 

The chlorobenzene mixture was allowed to cool to room temperature (overnight) and the white solid (NaCl) was removed by filtration. The resulting filtrate was acidified with acetic acid until a haze-free solution was obtained, and the pol3nner was isolated by a reverse precipitation. This procedure involved the addition of l of a 50 50 (by vol) MeOH acetone mixture to l of the polymer solution in a blender. The nonsolvent was added at a uniform rate over a period of ten minutes. The resulting solid was filtered and dried in a 65 C vacuum oven. In this fashion a total of 440.80 (86% yield) of BPA polyformal was collected. This material had an [n] (CHCI3) = 0.54 dl/g and contained 1.0% cyclics... 

High-Performance Polymers Aromatic Heterocyclic Monomers Thermally Stable Polymers High-Performance Composites Reactive Oligomers Aromatic Polyformals Star and Comb Shape Copolymers Polymers in Phase Transfer Catalysis Organometallic Polymers Poljmiers in Medical Applications Nitrogen-Containing Polymers Vinyl Organometallic Monomers Functionalized Polymers Anionic Copolymerizations Macromers... 

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