Polymers and polyfunctionality

Carothers, Wallace H.

doi:10.1039/tf9363200039

Cited by 465 publications

(337 citation statements)

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“…The result shows that the extent of reactions at this region varies from 63.33 to 78.57% for samples IV -I. Although these values are relatively lower than the range 75-80% obtained for reaction between phthalic anhydride and glycerol (Nagata, 1969;Carothers 1936), they indicate a significant degree of conversion. However, sample I (78.57%) falls within the range of the reactivity of phthalic anhydride and glycerol, with appreciable degree of conversion consistent with the ideal ratio of 1:2 for XASO: Glycerol for the alcoholysis reaction.…”

Section: Resultsmentioning

confidence: 56%

Formation and Characterization of Paint Based on Alkyd Resin Derivative of Ximenia americana (Wild Olive) Seed Oil

Oladipo¹,

Eromosele²,

Folarin³

2013

ENRR

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Alcoholysis-polyesterification method was used in the investigation of utilization of Ximenia americana seed oil in the formulation of alkyd resins. The extracted oilseed gave an oil yield of 45.7% (w/w) and the physicochemical characterization indicated it is semi-drying in nature with iodine value of 152.3 g I 2 100 g -1. The fatty acid analysis of the oil carried out earlier revealed oleic and linolenic as dominant fatty acids, having values of 72.1 and 10.3% respectively. Four grades of alkyds were formulated at 40% (I), 50% (II), 60% (III) and 70% (IV) oil lengths. The reaction progression was followed by determining the acid value of the aliquots for the reaction mixture at various time intervals beside the volume of water evolved. Kinetic studies showed that the reaction was second-order with values of 3.12 x 10 -4 , 2.44 x 10 -4 , 2. The 40 and 50% oil length alkyd films were resistant to acid, brine and water with little resistance to alkali. Characterization of paint based on two alkyd resin derivatives, 40 and 50% oil lengths, gave values for surface drying and tack-free property of less than 2 and 5 hours respectively in respect of the 40% oil length.

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Section: Resultsmentioning

confidence: 56%

Formation and Characterization of Paint Based on Alkyd Resin Derivative of Ximenia americana (Wild Olive) Seed Oil

Oladipo¹,

Eromosele²,

Folarin³

2013

ENRR

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“…[17][18][19][20] This point is critical as highly pure monomers are a prerequisite for achieving any substantial molecular weights in subsequent polycondensation reactions, owing to the correlation DP n = 1/(1Àp) between the degree of polymerization (DP n ) and the functional group conversion (p). [21] Exposure of methyl oleate to carbon monoxide and methanol in the presence of catalytic amounts of Pd(OAc) 2 -diol catalyzed by titanium alkoxides afforded the novel polyester 1 (Scheme 1, x = 1). GPC reveals molecular weights M w of typically 2 10 4 g mol À1 (M w /M n = 2); this data agrees with M n determined from 1 H NMR spectroscopic analysis of the end groups.…”

Section: Dorothee Quinzler and Stefan Mecking* Dedicated To Hans Brinmentioning

confidence: 99%

Linear Semicrystalline Polyesters from Fatty Acids by Complete Feedstock Molecule Utilization

2010

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“…The direct synthesis of PLA by polycondensation of lactic acid features the typical drawbacks of step-growth polymerizations: [26] owing to the correlation DP n = 1/(1Àp) between the degree of polymerization (DP n ) and the conversion (p) high molecular weights are only achieved at very high conversions (> 99 % conversion for a degree of polymerization of 100), and monofunctional impurities such as ethanol or acetic acid from fermentation limit the molecular weights attainable. [27] Nonetheless, high molecular weight PLA (M w 3 10 5 g mol À1 ) can be obtained by employing highly pure lactic acid and removing the water formed azeotropically during the polycondensation.…”

Section: Angewandte Chemiementioning

confidence: 99%

Nature or Petrochemistry?—Biologically Degradable Materials

2004

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Naturally occurring polymers have been utilized for a long time as materials, however, their application as plastics has been restricted because of their limited thermoplastic processability. Recently, the microbial synthesis of polyesters directly from carbohydrate sources has attracted considerable attention. The industrial‐scale production of poly(lactic acid) from lactic acid generated by fermentation now provides a renewable resources‐based polyester as a commodity plastic for the first time. The biodegradability of a given material is independent of its origin, and biodegradable plastics can equally well be prepared from fossil fuel feedstocks. A consideration of the overall carbon dioxide emissions and consumption of non‐renewable resources over the entire life‐cycle of a product is not necessarily favorable for plastics based on renewable resources with current technology—in addition to the feedstocks for the synthesis of the polymer materials, the feedstock for generation of the overall energy required for production and processing is decisive.

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Polymers and polyfunctionality

Cited by 465 publications

References 0 publications

Formation and Characterization of Paint Based on Alkyd Resin Derivative of Ximenia americana (Wild Olive) Seed Oil

Formation and Characterization of Paint Based on Alkyd Resin Derivative of Ximenia americana (Wild Olive) Seed Oil

Linear Semicrystalline Polyesters from Fatty Acids by Complete Feedstock Molecule Utilization

Nature or Petrochemistry?—Biologically Degradable Materials

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