Oligoester

Studying the reaction of carboxylic oligoesters with monohydric alcohols, Sorokina and Barshtein2231 found the reaction orders 1 and 0.5 with respect to acid and alcohol. However, they did not determine the reaction order relative to catalyst. According to these authors, the most important steps are ... 

The polymerization of cyclic low-molar-mass polycarbonates, polyarylates, and PBT to high-molar-mass thermoplastics has been extensively studied by the General Electric Company during the last decade.57,58 Due to very low viscosity, cyclic oligoesters can be processed like thermosetting resins but retain thermoplastic properties in the final state, after polymerization in the presence of suitable... 

The transesterification of PET with 2-ethylhexanol produces dioctyl terephthalate and small amounts of octyl(2-hydroxyethylene)terephthalate and terephthalate oligoesters. This mixture is used as a plasticizer for polyvinyl chloride.12... 

Cyclic esters, ring-opening polymerization of, 85-87 Cyclic lactams, 174 Cyclic oligoesters, 31 Cyclic oligomers, 63, 542 formation of, 39... 

In connection with studies on the ring-opening polymerization of cyclic acetals, we have undertaken investigations on the polymerization of bicyclic acetals, bicyclic oxalactone, and bicyclic oxalactam, which yield polysaccharide analogs, macrocyclic oligoesters, and a hydrophilic polyamide, respectively, some of which can be expected to be useful as novel speciality polymers. The monomers employed in the studies were prepared via synthetic routes presented in Scheme 1, starting from 3,4-dihydro-2H-pyran-2-carbaldehyde (acrolein dimer) I. 

Macromolecular Materials and Engineering 286, No.ll, 30thNov.2001, p.695-704 UV CURABILITY AND MECHANICAL PROPERTIES OF NOVEL BINDER SYSTEMS DERIVED FROM POLY(ETHYLENE TEREPHTHALATE)(PET) WASTE FOR SOLVENTLESS MAGNETIC TAPE MANUFACTURING. I. ACRYLATED OLIGOESTERS Farahat M S Nikles D E Alabama,University... 

The effect of incorporating p-hydroxybenzoic acid (I) into the structures of various unsaturated polyesters synthesised from polyethylene terephthalate (PET) waste depolymerised by glycolysis at three different diethylene glycol (DEG) ratios with Mn acetate as transesterification catalyst, was studied. Copolyesters of PET modified using various I mole ratios showed excellent mechanical and chemical properties because of their liquid crystalline behaviour. The oligoesters obtained from the twelve modified unsaturated polyesters (MUP) were reacted with I and maleic anhydride, with variation of the I ratio with a view to determining the effect on mechanical... 

Lipase catalysis induced the enantioselective polymerization, yielding optically active oligoesters and polyesters. The polymerization of racemic bis(2-chloroethyl) 2,5-dibromoadipate with excess of 1,6-hexanediol using lipase A catalyst produced optically active trimer and pentamer [46]. 

Crosslinked polymer particles with a rather complex structure, which have also been designated by the name microgels and recommended as components of metal effect paints, consist of carboxyl-terminated oligoesters of 12-hydroxy stearic acid which were reacted with glycidyl methacrylate, subsequently copolymerized with MMA and hydroxymethyl methacrylate and then crosslinked by hydroxy melamine [346]. 

Macrocyclic lattice hosts, 14 111 Macrocyclic mercuracarboranes, 4 216-217 Macrocyclic oligoesters, 25 125 Macrocyclic polymers, 14 252 Macrocyclic polythioethers, 23 707 Macrocylic ligands, 7 576 Macroemulsions, 10 113 16 433-434 Macrofouling organisms, in industrial water treatment, 26 149-150 Macrolide antibiotics, 15 271-320. See also Macrolides... 

Ruddick, C. L., Hodge, P., Zhuo, Y., Beddoes, R. L., and Helliwell, M., Cyclo-depolymerization of polyundecanoate and related polyesters characterisation of cyclic oligoundecanoates and related cyclic oligoesters, J. Mater. Chem., 9, 2399 (1999). 

Burch, R. R., Lustig, S. R. and Spinu, M., Synthesis of cyclic oligoesters and their rapid polymerization to high molecular weight, Macromolecules, 33, 5053 (2000). 

Oligoester l-2h (G) l-2h (G) Primarily adhesive, but with some resin degradation in cathodic polarization. 19... 

Oligoester Reaction product of 1,4-butanediol diglycidyl ether, 2-ethyl-1, 3-hexanediol, and 4-methy1-1,2-cyclohexane dicarboxylic acid anhydride MW 830 f = 4 r - 0.75. 

Liquid Crystalline Oligoester Diols as Thermoset Coatings Binders... 

Liquid crystalline (LC) oligoester diols were synthesized and characterized. They were crosslinked with a hexakis(methoxymethyl)melamine resin (HMMM) to form enamels of high crosslink density. Crosslinking... 

Here we report synthesis, properties, and crosslinking of thermotropic LC oligoester diols, and comparison of the properties of crosslinked enamels to those of enamels made from crystalline and amorphous diols. 

DIMIAN AND JONES Liquid Crystalline Oligoester Dials... 

Two types of non-LC oligoester diols were prepared for comparison. In one type, 2a-2g, liquid crystallinity was disrupted by substituting adipoyl chloride for terepthaloyl chloride in TOBC. 

Clear coatings containing oligoester diols 1, 2, and 3 crosslinked with a hexakis(methoxymethyl)melamine (HMMM) resin were prepared, baked and tested. 

Enamel Preparation. Soluble oligoester diols (Ib-ld, 2a-2g, and 3a-3g), HMMM, methyl isobutyl ketone (MIBK) and -toluenesulfonic acid ( -TSA) were thoroughly mixed in a 70/30/30/0.3 wt. ratio. The solution was cast on panels and baked at 150" for 30 min. Less soluble LC diols le-lg were melted, dispersed in MIBK, mixed with HMMM and -TSA in the above proportions and immediately cast as films. Oligoester diol la was too insoluble for enamel formation. 

Oligoester Diols. The physical properties of LC oligoester diols la-lg measured by GPC, VPO, DSC, and polarizing optical microscopy are summarized in Table I. 

All enamels had excellent adhesion, solvent resistance, and flexibility. Enamels made from LC diols Ib-lg were far superior to those made from control diols 2a-2g and 3a-3g in both hardness (5H-6H vs. H-2H 5H corresponded to about 20 KHN on a Tukon tester) and impact resistance (50 to >80 in-lb vs. 8 to 15 in-lb). Odd spacers lb and Id afforded the best properties in these formulations. Spacer variations did not measurably affect enamel properties in the control oligoesters. 

Oligoesters Diols. The synthetic method used to make ollgoester diols la-lg was adapted from Bilibin s method (17) for making main chain LC high polymers. A five-fold excess of H0(CH2)n0H as used to suppress molar mass. Spectral, chromatographic and analytical evidence indicated that the expected products were obtained. 

LC oligoester diols can be crosslinked with HMMM by carrying out the crosslinking reaction at temperatures between Tm and Tj. Crosslink density is high. Certain film properties of enamels made from LC diols are far superior to those of enamels made from non-LC diols. Films are hardened without substantially increasing Tg, and they retain the elasticity associated with low Tg. The mechanism of this property enhancement is uncertain, but the effect is substantial. Inclusion of LC diols in enamels offers vast possibilities for manipulation and improvement of film properties. 

Synthesis of Cross-Linkable Heterogeneous Oligoester Diols by Direct Esterification with p-Hydroxybenzoic Acid... 

This chapter is a preliminary report of our results. We found a procedure by which PHBA can be reacted with pre-formed amorphous oligoester diols at 230°C with minimal formation of phenol, an undesirable by-product. The products of such reactions are oligomers containing amorphous and ordered phases. They appear liquid crystalline. While the oligomer structures formed in the procedure described here differ from those of the previous paper, they form baked enamel films of exceptional hardness, toughness, and adhesion. 

Synthetic procedure. A linear oligoester diol was prepared by heating a mixture of PA, AA and NPG in a 1 1 3 mol ratio under No at 230° with removal of H2O until the acid number was 5 to 10 mg KOH/g. 

The linear oligoester diol was heated with salycilic acid and with MHBA using a similar procedure to yield modified polyols. Only 60% to 80% of theoretical distillate was obtained. 

WANG JONES Cross-Linkable Heterogeneous Oligoester Diols... 

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