New Thermoplastic Elastomers. Styrene Grafts on Lithiated Polydienes and Their Hydrogenated Counterparts

1973 ◽  
Vol 46 (4) ◽  
pp. 1044-1054 ◽  
Author(s):  
J. C. Falk ◽  
R. J. Schlott ◽  
D. F. Hoeg ◽  
J. F. Pendleton
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Room Temperature ◽  
Graft Copolymers ◽  
Gel Permeation Chromatography ◽  
Thermoplastic Elastomers ◽  
Proper Choice ◽  
Melt Flow ◽  
Gel Permeation ◽  
Poly Ethylene

Abstract Metalation of diene polymers such as poly (butadiene) and poly(isoprene) with sec-butyllithium and tetramethylethylenediamine in cyclohexane at room temperature forms lithiated polydienes. Reaction of the polylithiodienes with styrene or α-methylstyrene forms graft copolymers. The extent of metalation is much greater than previously reported metalations with n-butyllithium and tetramethylethylenediamine. The grafting efficiencies, determined by acetone extraction and gel permeation chromatography, are greater than 95 per cent. Graft copolymers of poly (styrene) on EPDM rubbers may also be prepared using this technique. The physical properties of the graft copolymers are a function of molecular weight, graft site level, and composition. Products at specific compositions and graft levels are thermoplastic elastomers. Their properties are comparable to SBS rubbers, and offer as an advantage high melt flow. Graft copolymers of poly(styrene) on poly(ethylene) and poly(ethylene-co-butene-1) result from the hydrogenation of the butadiene moeities of graft copolymers of poly (styrene) on 1,4-poly(butadiene) and 1,2 and 1,4-butadiene copolymers, respectively. Complete hydrogenation results in graft copolymers of poly(vinylcyclohexane) on poly(ethylene) and on poly(ethylene-co-butene-1). In both of these cases thermoplastic elastomers result if the proper choice of composition and graft level is made.

Study on Structure and Tanning Properties of Copolymer of Resorcinol and 3,5-Dihydroxyl Benzoic Acid

2012 ◽  
Vol 487 ◽  
pp. 48-52
Author(s):  
Sheng Hua Lv ◽  
Gong Rui ◽  
Di Li
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Gel Permeation Chromatography ◽  
Radical Copolymerization ◽  
Mass Ratio ◽  
Monomer Composition ◽  
Chrome Tanning ◽  
Gel Permeation

The radical copolymerization of resorcinol (RSC) and 3,5-dihydroxyl benzoic (DHBA) was carried out in water by the initiator of horseradish (HRP)/H2O2. It was discussed that the effects of monomer composition on the properties of the copolymer. The best monomer mass ratio of RSC:DHBA was 60:40 and the shrink temperature can reached to 88.5oC. The tanning result indicated that the copolymer of RSC and DHPA has particularly excellent tanning properties and can be served as leather tannage substitute for chrome tanning materials. And also the mechanism of the HRP initiated copolymerization was proposed. The structure and molecular weight of the copolymer was characterized by Fourier Transform Infrared spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). The copolymer can be as tannage and retannage in making leather process. The results showed that it has excellent tanning properties and retanning effects.

scholarly journals Correlations between retention volume and molecular size parameters in gel permeation chromatography of small molecules

1975 ◽  
Vol 28 (1) ◽  
pp. 189 ◽  
Author(s):  
RA Shanks
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Organic Molecules ◽  
Retention Volume ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Molar Volumes ◽  
Small Organic Molecules ◽  
Molecular Dimension ◽  
Gel Permeation

Gel permeation columns of Bio Beads S-X8 have been used to provide separation of oligomers and other small organic molecules. Results show successful separations up to molecular weight c. 600. The retention times of compounds have been correlated with the largest molecular dimension of the molecules and also with molar volumes.

Alternative Tanning Agent for Leather Industry from a Sustainable Source

2021 ◽  
Vol 116 (3) ◽  
Author(s):  
Cigdem Kilicarislan Ozkan ◽  
Hasan Ozgunay
Keyword(s):  
Molecular Weight ◽  
Corn Starch ◽  
Periodate Oxidation ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Leather Industry ◽  
Sodium Metaperiodate ◽  
Gel Permeation ◽  
Aldehyde Content

Dialdehyde starches with different aldehyde content from native corn starch were prepared by sodium periodate oxidation to be used as a tanning agent in leather making. For this purpose, native corn starch was oxidized with sodium metaperiodate in different molar ratios. After oxidation processes, the yields, solubility in water and aldehyde contents of the obtained dialdehyde starches were determined as well as structure characterizations by Proton Nuclear Magnetic Resonance Spectroscopy, Fourier Transform Infrared Spectroscopy and Gel Permeation Chromatography. Evaluating the gel permeation chromatography data, the dialdehyde starch samples which were thought to be in appropriate molecular weight/size to penetrate into skin fibers were selected to be used in the tanning process. Their tanning abilities were evaluated by investigating hydrothermal stabilities, filling and fiber isolation characteristics and physical properties determined by mechanical tests and organoleptically. From the evaluation of the results, it was revealed that sodium metaperiodate oxidized starches which have appropriate molecular weight and adequate aldehyde content has a remarkable tanning effect and can be utilized as a tanning agent with the advantages of not necessitating pickling process which means saving time and simplifying the production but more importantly offering an important advantage from an environmental point of view.

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