Linear aliphatic diols

H. Tetsuka, Y. Doi, H. Abe, Synthesis and thermal pct i es of novel periodic poly(ester-amide)s derived from adipate, butane-l,4-diamine, and linear aliphatic diols. Macromolecules 39 (2006) 2875-2885. 

Table 1.7 Polymerization of linear aliphatic diols catalyzed by the complex 8 under vacuum and nitrogen purge."...

Physical properties are related to ester-segment structure and concentration in thermoplastic polyether-ester elastomers prepared hy melt transesterification of poly(tetra-methylene ether) glycol with various diols and aromatic diesters. Diols used were 1,4-benzenedimethanol, 1,4-cyclo-hexanedimethanol, and the linear, aliphatic a,m-diols from ethylene glycol to 1,10-decane-diol. Esters used were terephthalate, isophthalate, 4,4 -biphenyldicarboxylate, 2,6-naphthalenedicarboxylate, and m-terphenyl-4,4"-dicarboxyl-ate. Ester-segment structure was found to affect many copolymer properties including ease of synthesis, molecular weight obtained, crystallization rate, elastic recovery, and tensile and tear strengths. 

RIM elastomers based on aromatic diisocyanates and short linear diols are more inclined to form crystalline aggregates than the identical formulations based on cycloaliphatic and linear aliphatic diisocyanates and short linear diols. 

Poly(carbonate-linked ethylene glycols) of the general structure, HO-(R-0-CO-0)n-R-0H, PPG s Duracarb 120, ( 2.85), where R represents a difunctional linear, aliphatic moiety such as PPG (molecular weight 850-1500), suitable for the preparation of flexible PURs, while the analogous diol in which R represents an alicyclic moiety, PPG s Duracarb 140 ( 2.93 molecular weight 600-1000) is suitable for the preparation of rigid PURs. 

Linear aliphatic fluorinated polyurethanes have been tested with respect to the location of the fluorine atoms in the diol or diisocyanate component. Fluorine atoms introduced into the diisocyanate unit increase the stability of the urethane group, but the presence of these atoms in the diol unit favours dissociation of the urethane group to monomer. Comparison of PTFE and perfluoroamidine polymers shows that introduction of triazine rings in fluoromethylene chains enhances their stability. 

Lipase-catalyzed synthesis of aliphatic polyesters via diacid/diol polycondensation reactions have been explored by us and others at temperatures of 90°C and below (4,5). The substrates used in previous studies are a,a)-linear aliphatic diacid and/or diol monomers with six or more carbons. Herein we report a new method that allowed the first lipase-catalyzed synthesis of high molecular weight PBS fi om practical monomer precursors. 

Linear aliphatic chols are widely used as raw materials for polymers. Polymers synthesized from even-carbon diols tend to show excellent polymer properties. 1,4-Butanediol is very important as raw material for various polymers such as urethanes and polybutylene terephthalate (PBT), which is an engineering plastic. Since Celanese Corporation described a PBT resin in 1970, the demand for PBT resin, which is mainly used for automotive, electrical, and electronic equipment parts, has been expanding rapidly [1]. THF is also a major 1,4-butanediol derivative as a raw material for poly(tetramethylene ether) glycol used for artificial leather and elastic fibers in addition to being a high-performance solvent. Significant growth in demand for these 1,4-butanediol derivatives is expected in Asia, primarily in China. 

Poly(8-caprolactone) 1 is a simple, linear, aliphatic polyester formed by the ringopening addition polymerisation of 8-caprolactone, normally initiated by an alcohol or diol in the presence or absence of a catalyst. The polymer has a regular structure and is crystallisable. PCL crystallises to about 50% in the form of spherulites [10]. 

In the last decade, extensive and systematic studies were imdertaken of the synthesis structure, properties, and application of linear thiopolyesters (123) prepared by melt polymerization from various new aliphatic-aromatic thiodicarboxyhc acids and aliphatic diols as well as aliphatic-aromatic bis[4-(2 -hydroxyethylthiomethyl)phenyl]methane (EM) (291-296,302,303). 

The growing interest in polyurethane elastomers because of their unique properties, as well as in sulfur-containing pol5uners, prompted scientists in the last decade to undertake studies on the synthesis and properties of a novel class of thiopolyurethanes containing thioether linkages in the main chain, derived from various new diol components as aliphatic-aromatic simple thiodiols (308-314) and linear thiopolyester diols (293,295,296). 

Although PET and PBT are widely used, better thermal and mechanical properties are desired for some applications. Higher performance in semiaromatic polyesters was obtained from polyalkene naph-thalates. These semicrystalline polyesters are prepared by the condensation polymerization of naphtha-lene-2,6-dicarboxylic acid and flexible aliphatic diols. The naphthalene moiety imparts stiffness to the linear polymer backbone, leading to improved physical and mechanical, barrier, chemical resistance properties, and UV-ray screening performance. Poly(ethylene naphthalene-2,6-dicarboxylate), PEN, became commercially available from Teijin Ltd. in the early 1970s. PEN has a Tg and of 125 and 268°C, respectively [34]. Its structure appears in Fig. 1.18. 

According to O. Bayer, the latter procedure, which is used especially for the preparation of elastomeric polyurethanes, is carried out in two separate stages. First, a carefully dried, relatively low-molecular-weight, aliphatic polyester or polyether with hydroxy end groups is reacted with an excess of diisocyanate. A chain extension reaction occurs in which two to three linear diol molecules are coupled with diisocyanate, so as to yield a linear polymer with some in-chain urethane groups and with isocyanate end groups. 

Structure, Size, and Orientation of the Adsorbed Organic Molecule. In general, hydrocarbon chains, whether linear or branched, are expected to interact relatively weakly, both with water molecules and with the electrode material. Aliphatic molecules with functional groups (e.g., diols, sugars, or thiourea) may interact strongly with water molecules via H bonds and this interaction affects... 

Polyester Polyols. Polyester polyols are based on saturated aliphatic or aromatic carboxylic acids and diols oi mixtures of diols. The carboxylic add of choice is adipic acid because of its favorable cost/performance ratio. For elastomers, linear polyester polyols of ca 2000 mol wt are preferred. Branched polyester polyols, formulated from higher functional glycols, are used for foam and coatings applications. Phthalates and terephthalates are also used. 

Probably the simplest polymer formation reaction involving phosgene is that with the dihydric aliphatic alcohols, such as ethylene, propylene or butylene glycol viz. ethane-1,2-diol, propane-1,3-diol or butane-1,4-diol) this reaction results in the formation of linear, wax-like polymers suitable for the impregnation of materials requiring water barrier properties [1133]. 

---