Polyester diols

Polyester blends Polyester carbonates Polyester containers Polyester-cotton blends Polyester, cross-linked Polyester diols... 

In addition, polyester polyols are made by the reaction of caprolactone with diols. Poly(caprolactone diols) are used in the manufacture of thermoplastic polyurethane elastomers with improved hydrolytic stabiHty (22). The hydrolytic stabiHty of the poly(caprolactone diol)-derived TPUs is comparable to TPUs based on the more expensive long-chain diol adipates (23). Polyether/polyester polyol hybrids are synthesized from low molecular weight polyester diols, which are extended with propylene oxide. 

Polyester and polyether diols are used with MDI in the manufacture of thermoplastic polyurethane elastomers (TPU). The polyester diols are obtained from adipic acid and diols, such as ethylene glycol, 1,4-butanediol, or 1,6-hexanediol. The preferred molecular weights are 1,000 to 2,000, and low acid numbers are essential to ensure optimal hydrolytic stabihty. Also, caprolactone-derived diols and polycarbonate diols are used. Polyether diols are... 

Polyester diols are often combined with polyether diols to provide green strength through crystallization or elevated r . Most prevalent and least expensive is hexamethylene diol adipate (HDA) with a Tm of about 60°C. A variety of polyesters are available with various levels of crystallinity — from wax-like to amorphous — and crystallization rate, and with values ranging well below 0°C to above room temperature. Polybutadiene diols are the most expensive and most hydrophobic. They provide low surface tension and thus good wet out of non-polar surfaces. 

Technical Data Sheet — Polyester Diol S-105. Ruco Polymer Corporation, Oct. 1995. Trappe, G., In Buist, J. and Gudgeon, H. (Eds.), Advances in Polyurethane Technology. Maclaren, 1968, p. 80. 

TPU is usually made from hydroxyl-terminated polyether or polyester diols, diisocyanates, and bifunctional chain extenders. Since the composition, the synthetic method, molecular weight, and its distribution are all changeable, there are numerous types of TPUs available, and their prices and properties vary significantly. 

The major PET manufacturers are depolymerizing scrap PET with glycols (glycolysis) or methanol (methanolysis) to form low-molecular-weight polyester diols (and BHET) and dimethyl terephthalate.3 The purified products are then used to make new products. Goodyear uses glycolysis to make REPETE, a new product which contains 10-20% recycled PET. Hoechst Celanese used methanolysis to produce DMT for repolymerization. Eastman Chemicals uses depolymerization of PET to recover used X-ray scrap. 

Semi-rigid foams take much longer to return to their original dimensions after deformation than flexible foams. They offer exceptional shock absorbance, which suits them for many protective applications, especially in automobiles. In general, we use polyester diols in semirigid foams because of their superior mechanical properties. 

Polyester-6/oe/ -polycarbonate, 7 646 Polyester bottles, recycling, 20 54-56 Polyester can coatings, 13 39 Polyester carbonates, 19 822 Polyester-carboxyl powder coatings 1998 production, 7 49 Polyester composites, cross-linked, 20 114 Polyester composition, determining, 20 21 Polyester diols, 25 476... 

Linear saturated polyesters of low Molecular weight (less than 10,000) can be obtained by condensing a diol with a diacid. Molecular weight can be controlled by adding a monohydric alcohol or monocarboxylic acid. These polymers are used as plasticisers or as polyester diols for making polyurethanes. 

A direct esterification procedure by which a linear polyester diol can be modified with p-hydroxybenzoic acid (PHBA) was demonstrated. The products are oligomers in which phenolic end-groups appear to predominate. They are heterogeneous and are probably liquid-crystalline when 30 wt% or more of PHBA is incorporated. The procedure has the advantage that appears adaptable to large scale production but the disadvantages that the polyols are predominately phenolic and are contaminated with small amounts of phenol and unreacted PHBA. 

One of the more advanced technical offerings from castor oil is a line of polyester diols, triols, and higher functional polyols derived from 100% castor oil as products for the preparation of polyurethane prepolymers and elastomers [68]. The Polycin line of polyols are prepared by transesterification of ricinoleic acid and derivatives. The producers (Vertellus) offer diol and triol products, as well as a recently developed series of diol and triol glyceryl ricinoleate esters that are stated to be prepared from 100% castor oil, making them fully renewable in content. The products are recommended for coatings, sealants, and adhesive applications. 

PU elastomers based on a polyester diol as the soft block and isocyanate groups coupled via a chain extender as the rigid block, have been investigated. The role of the chain extender is to induce some mobility and disorder within the hard microdomains. The elastomers are selectively deuterated in the rigid block. 2H NMR spectra show the coexistence of a solid and a mobile fraction [89]. The solid fraction shows no onset of fast molecular motions at all, while the mobile fraction increases with temperature. These results suggest that some of the hard microdomains (perhaps the most disordered ones) melt successively when temperature is raised. 

In our lab., the poly transesterification was used to obtain polyester diols [25] ... 

The saturated analogue of MDI, 4,4 -dicy-clohexyl methane diisocyanate, has found limited use as an aiphatic isocyanate in adhesives. This material is known by a variety of names including Desmodur W (Bayer), hydrogenated MDI (or HMDI or Hl2MDI), reduced MDI (RMDI), and saturated MDI (SMDI), It is a low-viscosity liquid with a fairly high vapor pressure, so it too must be handled with care. In adhesive compositions, the diisocyanate usually is used to make an isocyanate functional prepolymer by reacting excess diisocyanate with a hydroxyl or amine functional polymer such as a polyester diol. 

Figure 7. Examples of different modes of chromatography (a) calibration curves (schematic), (b) SEC separation of oligomeric polyesters with different molar mass, (c) critical chromatogram (LACCC) of polyester diole terminated sample is main compound, and (d) gradient HPLC run of the same polyester sample showing multiple distributions.

Preparation of Microcellular Foams. The major polyols for microcellular elastomers include aliphatic polyester diols having a molecular weight of about 1,000 to 3,000, and poly-epsilon-caprolactones. Poly(oxytetramethylene) glycols (PTMEG) can also be used. The polyisocyanates to be used for microcellular elastomers are TDI-prepolymers and liquid MDI, i.e., carbodiimide-modified MDI or urethane-modified MDI. Low-molecular-weight, active-hydrogen compounds such as chain extenders (difunctional compounds) and... 

As an alternative to polyester diols, polyethers (such as polypropylene glycol) that are even more flexible are often used. These are bonded to smaller (150-nm) rigid domains from the (aromatic) isocyanate. The chain extender in the formulation may be either flexible or rigid. 

The materials employed in these formulations consisted of bitolylene diisocyanate (3,3 -dimethyl-4,4 -biphenylene diisocyanate, 136T Upjohn Co.) referred to as T0DI, a polyether diol (tetramethyleneoxide polyol, Polymeg 2000, Quaker Oats Co.), a polyester diol (caprolactone polyol, PCP-200, Union Carbide Corp.) and a chain extender, 1,4-butanedio1 (Aldrich Chemical Co.). The formulations were prepared by a two-step procedure. In... 

These improved properties may be related to 1) increased hydrogen bonding due to the increased polyester diol content, 2) increased hard segment content, and 3) evidence of crystallinity in the hard segment domain. All effects result in a higher modulus material. The structure-property relationships of these formulations in terms of their crystalline morphology are discussed in another paper. ... 

The two-phase polyurethanes were synthesized in the usual way starting from a polyester diol which is reacted with a diisocyanate and finally the chain extension reaction is achieved by... 

The first urethane was synthesised, by this route, as early as 1849 by Wurtz [6,16,22,30]. In 1937, following very systematic and intensive research works at IG Farbenindustrie, in Germany, Dr. Otto Bayer synthesised the first polyurethane, by the reaction of a diisocyanate with a polyester having two terminal hydroxyl groups (called polyester diol, in fact an a,(o-telechelic polymer with terminal hydroxyl groups) [1,2] ... 

Chapter 12.5). Polyester polyols in reality, have the theoretical functionality, which is a great advantage for many polyurethane applications. For polyester diols the functionality is 2 OH groups/mol. This structural aspect results in the polyester diols giving PU elastomers with excellent physico-mechanical properties, superior to all polypropylene glycols obtained by anionic PO polymerisation. 

It is very clear, that the reaction between a dicarboxylic acid with a glycol always results in a polyester diol, the functionality being exactly 2 OH groups/mol. The functionality of a branched polyester polyol is calculated by the Chang equation [22] ... 

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