Introduction to farnesene-based polyols / Herbert Chao in ADHESIVES & SEALANTS INDUSTRY (ASI), Vol. 25, N° 4 (04/2018)  

[article]  inADHESIVES & SEALANTS INDUSTRY (ASI) > Vol. 25, N° 4 (04/2018) . - p. 21-27 Titre : Introduction to farnesene-based polyols Type de document : texte imprimé Auteurs : Herbert Chao, Auteur ; Steve Henning, Auteur ; Nan Tian, Auteur ; Tomas Tmka, Auteur Année de publication : 2018 Article en page(s) : p. 21-27 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Hydrophobie Polyaddition Polyfarnesène Polymères -- Synthèse Polyols Polyuréthanes Rhéologie Index. décimale : 668.3 Adhésifs et produits semblables Résumé : A new hydrophobic polyol derived from a renewable source offers lower viscosity than hydroxyl-terminated polybutadienes (HTPBs) of the same molecular weight. Hydroxyl-terminated polybutadiene (HTPB) resins are known to have a higher viscosity than polyether polyols of the same molecular weight. A new hydrophobic polyol derived from renewable resources, namely polyfarnesene diol, has been developed having lower viscosity than the HTPBs of the same molecular weight.Hydroxyl-terminated polybutadiene (HTPB) resins are known to have a higher viscosity than polyether polyols of the same molecular weight. A new hydrophobic polyol derived from renewable resources, namely polyfarnesene diol, has been developed having lower viscosity than the HTPBs of the same molecular weight. Trans-b-farnesene* was used in the present study for the anionic processes (farnesol and other oxygenated byproducts removed). Trans-b-farnesene is produced in small quantities in natural processes, but typically both a- and b-isomers are present. The supplier has modified the common yeast Saccharomyces cerevisiae to efficiently produce large amounts of trans-b- farnesene. Sugar is fermented to the target molecule in a manufacturing-ready strain that used 21 enzymatic steps in a native pathway. Only the b-isomer is active in polymerization, making this fermentation route especially attractive industrially. This article summarizes the preparation of polyols based on trans-b-farnesene via anionic polymerization. Polyurethanes derived from polyfarnesene diol (PFD), poly(farnesene-co-butadiene) diol, and polyol blends of polyfarnesene diol and hydroxyl-terminated polybutadiene are evaluated and compared. Note de contenu : - ANIONIC POLYMERIZATION - POLYURETHANE SYNTHESIS - RESULTS AND DISCUSSION : Miscibility of polyfarnesene diols with other polyols - Polyurethanes derived from polyol mixture containing diols - POlyurethanes derived from copolymer diols based on different ratios of farnesene and butaniene - Polyurethane derivef rom th epolyol mixture conatining polyfarnesene diol and poly bd polyol - Viscosity of polyol blends and copolymer polyols - FIGURE : Viscosity of polyol blends and polyols of copolymers made from farnesene and butadiene in various ratios - TABLES : 1. Compatibility results of polyfarnesene diol and hydrogenated polyfarnesene diol - 2. Polyurethanes of 30% hard segment content derived from polyol blends of PFD 2000 and Krasol LBH 2000 resin - 3. Polyurethanes of 40% hard segment content derived from polyol blends of PFD 2000 and Krasol LBH 2000 resin - 4. Polyurethanes of 30 % hard segment content derived from polyols based on farnesene and butadiene random copolymers - 5. Polyurethanes of 40 % hard segment content derived from polyolss based on farnesene and butadiene random copolymers - 6. Polyurethanes of 30 % hard segment content derived from polol blends of PFD 2000 and poly bd R45HTLO resin - 7. Polyurethanes of 40 % hard segment content derived from poloyl blends of PFD 2000 and poly bd R45HTLO resin - 8. Polyurethanes of 30 % hard segment content derived from poloyl blends of PFD 2000 and poly bd R20LM resin - Polyurethanes of 40 % hard segment content derived from poloyl blends of PFD 2000 and poly bd R20LM resin - TABLES : En ligne : https://www.adhesivesmag.com/articles/96166-introduction-to-farnesene-based-poly [...] Format de la ressource électronique : Web Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30632 [article]

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Novel products / Herbert S. Chao in ADHESIVES AGE, Vol. 45, N° 10 (10/2002)  

[article]  inADHESIVES AGE > Vol. 45, N° 10 (10/2002) . - p. 26-30 Titre : Novel products : New resins with low hydroxyl functionality provide urethane prepolymers with low viscosity and excellent storage stability Type de document : texte imprimé Auteurs : Herbert S. Chao, Auteur ; Nan Tian, Auteur Année de publication : 2002 Article en page(s) : p. 26-30 Langues : Américain (ame) Catégories : Hydroxyle En chimie organique, un hydroxyle (ou oxhydryle) peut désigner deux entités. Un groupement -OH, appelé aussi hydroxy, qui se rencontre en particulier dans les alcools et les phénols. Un radical : HO^{\bullet}. Il est produit par exemple lors de réactions de dissociation de peroxydes, en présence d'ions de métaux de transition (Fe(II), Cu(I), réaction de Fenton), de chauffage ou de rayonnement. Polybutadiène Polyuréthanes Stabilité au stockage Urethanes Index. décimale : 668.3 Adhésifs et produits semblables Résumé : Poly bd resins with lower hydroxyl functionality than the standard R45HTLO have been developed by Sartomer Co. These products, LF-1, -2, and -3, provide urethane prepolymers with lower viscosity and better storage stability compared with those derived from the product R45HTLO of the same NCO index. Furthermore, low-functionality Poly bd resins, polyurethanes, with and without chain-extenders, were prepared via two-step and one-step syntheses, respectively. As anticipated, more thermoplastic properties were noticed for the polyurethanes derived from Poly bd resins with low-hydroxyl functionality. Poly bd resin, a hydroxyl-terminated polybutadiene liquid, has been widely used in adhesives, sealants and electrical applications owing to its low-glass transition temperature (-75 degrees C), hydrophobicity, acid-base resistance and excellent dielectric properties. As a hydrocarbon-based polyol, Poly bd resin has been widely used in polyurethane and polyester chemistries by reacting with polyisocyanates or carboxylic acid derivatives, respectively. In contrast to polyester or polyether polyols, Poly bd resin-based thermoset resins having low surface tension can easily accommodate a large quantity of inorganic fillers and hydrocarbon plasticizers, such as bitumen and soybean oil. The fillers and plasticizers can improve mechanical properties of the products and lower cost. Although Poly bd resin contains a predominantly linear backbone structure, it also contains a small portion of branched polymer, resulting from the radical polymerization process. Thus, the commercial product has a hydroxyl functionality of 2.4 to 2.6 per chain on average. This branched structure occasionally imposes limitations on customers' processes or product performance especially when they seek design flexibility between thermoplastic and thermoset properties. To offer more choices and flexibility in the Poly bds, three new grades-- LF-1, -2, and -3-with lower hydroxyl functionality of 2 to 2.3 are introduced. Note de contenu : - Gumstock properties derived from low functionality Poly bd resins - Prepolymer viscosity from Poly bd resins with regular and low functionality - Stability of prepolymer viscosity from Poly bd R45HTLO and LF materials - Two-step urethane elastomer from prepolymers 2-ethyl-1,3-hexandiol - Procedures of preparing prepolymers - Two-step urethane elastomer from prepolymers and 2-ethyl-1,3-hexandiol. Procedures for preparing urethanes via two-steps process En ligne : https://drive.google.com/file/d/14VsLrYsbwfgKWQWmklB6G8Tojnd1cz4y/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=20029 [article]

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