What are Polymers?

What are Polymers?
(Chemistry Department - Michigan State University)

Polymers
1. Introduction
2. Writing Formulas for Polymeric Macromolecules
3. Properties of Macromolecules
4. Regio and Stereoisomerization in Macromolecules

Synthesis of Addition Polymers
1. Radical Chain-Growth Polymerization
2. Cationic Chain-Growth Polymerization
3. Anionic Chain-Growth Polymerization
4. Ziegler-Natta Catalytic Polymerization

Copolymers
1. Addition Copolymerization
2. Block Copolymerization

Condensation Polymers
1. Characteristics of Condensation Polymers
2.Thermosetting vs. Thermoplastic Polymers

Procedure for publication of IUPAC Technical Reports and Recommendations

Recommendations & Reports

The "Procedure for publication of IUPAC Technical Reports and Recommendations" provides instructions for submission of the manuscripts to the IUPAC Division and the ICTNS. Guidelines of how to prepare manuscripts can be found in "Guidelines for Drafting IUPAC Technical Reports and Recommendations". As part of the review process IUPAC recommendations on nomenclature and symbols are made made available for public comment as provisional recommendations.

Lists of recent publications are available, sorted by division, i.e. discipline of chemistry, or by year. Each listing includes the report's title and reference, and when available, a link to the abstract.

Choose one of the following listings:

Year 2007 - 2006 - 2005 - 2004 - 2003 - 2002 - 2001 - 2000
---------- 1999 - 1998 - 1997 - 1996 - prior 96

Analysis of High Polymers

Analysis of High Polymers
John Mitchell, Jr., and Jen Chiu, Plastics Departmenf, E. 1. du font de Nemours & Co., Inc., Wilmington, Del. 7 9898
(Anal. Chem.; 1971; 43 (5); 267R)

THIS REVIEW covers significant developments in polymer analysis during the past two years. Stress is placed on techniques providing information on chemical and physical structure. No attempt was made to provide details of elastomers analysis, since these are reviewed in another section of this issue. However, reference is made to these materials where the techniques involved appear to provide useful background information on the more rigid polymers. References from Chemical Absfracts through November 1970 are noted.

RALPH H. COLBY PUBLICATIONS: Polymer Dynamics and Complex Fluids Rheology

RALPH H. COLBY PUBLICATIONS

Group Leader: Ralph H. Colby
Professor of Materials Science and Engineering

Polymer Science Program
Dept. of Materials Science and Engineering
The Pennsylvania State University

Favorite Journals

Acta Biomaterialia

Acta Materialia

Additives for Polymers

Advanced Engineering Materials
















Advanced Materials

Advances in Polymer Science

Advances in Polymer Technology

Biomacromolecules

Biomaterials

Polymer Chemistry Hypertext

Polymer Chemistry Hypertext provides an overview to the information included in a second semester polymer science course. The hyperlinking of the concepts allows the student to quickly obtain an overview of the concepts.

This site contains: concepts about polymer science, polymer library, and guidelines in polymer field. A example is:

How to Build a ZIMM PLOT

Chemical Company

DuPont

BASF











The Dow Chemical Company

Guías y Apuntes de Ingeniería de Materiales mención Polímeros - USB

Guías y Apuntes de Ingeniería de Materiales mención Polímeros - USB

En los siguientes días se publicarán algunos archivos vinculados a las siguientes asignaturas:

Pensum Ingeniería de Materiales mención Polímeros

MT2231: Polímeros I

Programa MT2231

MT2242: Propiedades Físicas de Polímeros I

Programa MT2242

MT2243: Propiedades Físicas Polímeros II

Programa MT2243

Bibliografía muy importante para el Curso de Propiedades,

MT3242: Caracterización de Polímeros

Programa MT3242

MC2511: Viscoelasticidad

Programa MC2511

MT3232: Polímeros II

Programa MT3232

MT2284: Laboratorio de Propiedades Físicas de los Polímeros

Programa MT2284

MC2512: Reología de Polímeros

Programa MC2512

MT2283: Laboratorio de Polímeros I

Programa MT2283

Guía Lab. I Polímeros

MT3251: Aditivos

Programa MT3251

Guía Aditivos

Agentes Nucleantes

MC2513: Tecnología del Plástico I

Programa MC2513

MC2582: Laboratorio de Tecnología del Plástico I

Programa MC2582

Guía Lab. I Tecnología del Plástico

MC2583: Laboratorio de Tecnología del Plástico II

Programa MC2583

Guía Lab. II Tecnología del Plástico

MT3283: Laboratorio de Polímeros II

Programa MT3283

MC2514: Tecnología del Plástico II

Programa MC2514

MC3127: Diseño II

Programa MC3127

Guía de Diseño II

MC2516: Elastómeros

Programa MC2516

Guía de Elastómeros

MC2515: Ingeniería de Moldes

Programa MC2515

Guía de C-MOLD y Resin Data

(guías compiladas y extraídas del portal C-MOLD Design Guide)

MC2584: Laboratorio de Tecnología del Plástico III

Programa MC2584

PROGRMAS COMPLETOS DE Ingeniería de Materiales mención Polímeros - USB

Nota: en esta sección se suministrarán archivos de ayuda y respaldo para aquellos estudiantes de esta carrera de la Universidad Simón Bolívar

Recomiendo una excelente biblioteca con libros en formato .pdf y .djvu, que es de utilidad para complementar los estudios. Lo único que deben hacer es ir a GIGAPEDIA, suscribirse y después disfrutar de la inmensa información que hay disponible gratuitamente. Otras vías son emplear programas P2P, como por ejemplo Ares Galaxy

The Glass Transition Temperature in Homologous Series of Linear Polymers

The Glass Transition Temperature in
Homologous Series of Linear Polymers
B. M. GRIEVESON*
(Polymer, Volume 1, 1960, Pages 499-512)

Members of three homologous series of linear aliphatic polyesters were synthesized and their glass transition temperatures are reported. The theory of glass transition temperatures in random copolymers is applied to polymers in homologous series by treating them ag copolymers of the first member of the series with polymethylene. It is shown that each methylene group added to a polymer to Jorm the next member of the series makes a constant specific contribution to the glass transition temperature lust as does the addition of each homopotymer unit in a random copolymer. There is a discrepancy between the observed and predicted values of the contribution made by each methylene group.

INTRODUCTION

A KNOWLEDGE of the relationship between the chemical structure and glass transition temperature (Tg) of polymers is an important aid in the search for materials with specific physical properties in a given temperature range. The effect of changing chemical structure in homologous series of polymers has been studied by many workers. Interest has been mainly concentrated on locating glass transition temperatures, although some quantitative measurements of specific volume-temperature relationships in the region of Tg have been made (1, 2). The results of these investigations have shown that the insertion of new chemical units into a polymer chain leads to a change in the glass transition temperature. The direction and amount of the change can be predicted qualitatively from a knowledge of the steric nature of the inserted unit and its effect on the configuration of the polymer and the interaction between polymer chains. From studies of glass transition temperatures in random copolyrners, Gordon and Taylor (3), Mandelkern and co-workers (1), and Wood (4) have shown that each homopolymer makes a specific partial contribution to the glass transition temperature in proportion to its own Tg and its weight fraction in the copolymer. If the quantitative relationship developed for random copolymers is applied to the insertion of a new chemical unit into a homopolymer, it should be possible to predict the resultant change in glass transition temperature.

Three homologous series of linear aliphatic polyesters have been prepared together with some random and block copolyesters and polyester melt blends. The glass transition temperatures of these polymers have been measured, and these results together with those for homologous series studied by other workers are examined in the light of the theory of glass transition temperatures in random copolymers.

EXPERIMENTAL

Preparation of polyesters

The polyesters were prepared by condensation of dibasic acids with equimolar proportions of a glycol at 200°C in a stream of oxygen-free nitrogen. In order to obtain polymers of the requisite number-average molecular weight (greater than 10,000), in a reasonable time, it was necessary to reduce the pressure in the reactor to 1 mmHg when the polymer molecular weight reached 5,000. Condensation was continued until the number-average molecular weight reached at least 10,000.

The oxalate, malonate and n-alkylmalonate polyesters were prepared from the diethyl esters of the corresponding acids since the acids themselves are unstable at the reaction temperature. The diethyl esters were heated at 150°C with equimolar proportions of the glycol until the theoretical amount of ethyl alcohol was almost completely distilled out of the reaction mixture. The temperature was then raised to 200°C and the polycondensation completed under reduced pressure. Polymers of the desired molecular weight were obtained with relative ease in some systems, but when necessary 0.01 per cent of anhydrous zinc acetate was added as a condensation catalyst.

The diethylene succinate-sebaeate random copolymers were prepared from a mixture of succinic acid and sebacic acid in the required proportions, together with an equimolar amount of diethylene glycol, by the same condensation technique as described above.

The block copolymers were prepared from poly(diethylene succinate) and poly(diethylene sebacate), both of approximately 2,000 number-average molecular weight. These low molecular weight polyesters were mixed inthe required proportions with an equimolar amount of hexamethylene di-isocyanate (H.M.D.I.) and allowed to react at 60°C to give a block copolymer having a molecular weight of approximately 20,000. Although this method of block copolymer formation involves the introduction of urethane linkages into the polyester chain, it has the advantage that it canbe performed at relatively low temperatures. At elevated temperatures, ester interchange occurs easily and would result in a disordering of the units of the two blocks, thus producing a random copolymer. The introduction of urethane linkages into the polyesters will result in changes from the Tg of the pure polymers. H.M.D.I. was chosen as the linking agent because, although it is less reactive than the aromatic di-isocyanates, its structure is much more similar to that of the linear aliphatic polyesters. It should, therefore, cause smaller deviations from the true Tg of the polyesters. For purposes of comparison, high molecular weight homopolymers of diethylene succinate and diethylene sebacate were also prepared by chain-extending polyesters of molecular weight 2,000 with H.M.D.I.

Molecular weight measurements

Number-average molecular weights were estimated by end-group analysis. The hydroxyl end-groups were measured by acetylation with pyridine/acetie anhydride reagent and the carboxyl end-groups were titrated with 0.1 N alcoholic potash. The reproducibility of the molecular weight measurements (about +/- 5 per cent at mol. wt. 2,000) became poorer at higher molecular weights, but the accuracy was sufficient to allow a molecular weight versus glass transition temperature relationship to be established for poly(diethylene adipate), Figure 1. After this relationship was obtained, molecular weight

measurements were only used to follow the polyesterification and to check that all the polyesters prepared had a molecular weight above 10,000.

Measurements of glass transition temperature

A penetrometer technique similar to that described by Edgar and Ellery (5) was used to make a preliminary approximate estimate of Tg for each polyester. A fiat-ended needle was fixed in the bottom of a vertical brass spindle which was mounted in a rigid frame so as to move freely in a vertical direction. The spindle was loaded to give a pressure of 400 g/mm^2 at the needle point. A dial gauge (reading to 0.0005 in.) was mounted in the frame to measure the vertical movement of the spindle. The polymer sample in a small tray 1 in. in diameter and 0.3 in. deep was gently heated to about 30°C above its melting point and then damped in the penetrometer frame below the needle point. The polymer and the lower part of the apparatus were immersed in n-hexane which had been cooled to -100°C and the penetrometer needle was lowered onto the polymer surface. The temperature of the hexane hath was raised by about 1°C per minute and readings of the dial gauge were taken at 2 min intervals. Figure 2 shows a typical penetrometer curve. The intersection of the tangents to the two arms of the curve gave a reproducible temperature Tb (the penetrometric brittle poin0 which generally lay about 5°C above the dilatometric glass transition temperature Tg (see Table 2). With all of the polyesters studied, smooth penetrometer curves like Figure 2 were obtained. This finding differs from that of Edgar (6) who found that with poly(ethylene terephthalate) an abrupt change occurred in the slope of the penetrometer curve at the temperature at which the dilatometric Tg was observed.

REFERENCES

1 MANDELKERN, L., MARTIN, G. M. and QUINN, F. A., J. Res. nat. Bur. Stand., 1957, 58, 137

2 ROGERS, S. S. and MANDELKERN, L., J. Phys. Chem., 1957, 61, 985

3 GORDON, M. and TAYLOR, J. S., J. Appl. Chem., 1952, 2, 493

4 WOOD, L. A., J. Polym. Sci., 1958, 28, 319

5 EDGAR, O. and ELLERY, E., J. Chem. Soc., 1952, p. 2633

6 EDGAR, O., J. Chem. Soc., 1952, p. 2638

...This paper will continue...

EINSTEIN'S ANNUS MIRABILIS 1905

EINSTEIN'S ANNUS MIRABILIS 1905

THE HIGH RESOLUTION NMR SPECTROSCOPY OF POLYMERS

THE HIGH RESOLUTION NMR SPECTROSCOPY OF POLYMERS

F. A. Bovey

Bell Telephone Laboratories, Incorporated, Murray Hill, New Jersey 07974

(Progress in Polymer Science, Volume 3, 1971, Pages 1-108)

Nuclear magnetic resonance (NMR) spectroscopy has proved to be of great significance in many aspects of polymer science. Because of the rapid expansion of this field, a review is felt to be justified at this time even though a number have appeared in recent years. ^(1-6) Earlier NMR studies have dealt with solid polymers, and the spectra obtained have been of the so-called "wide-line" type. In such spectra, as in the corresponding spectra of non-polymeric solids, analysis of the resonance lines, particularly if known as a function of temperature, can give information about the packing and motion of the polymer chains. ^(7-9) To such studies have more recently been added the measurement of the spin-lattice and spin-spin nuclear relaxation times, T1 and T2 (see below), in both solid state and solution, providing further insight into the motion and interaction of polymer chains. ^(10-21)

The present review will deal primarily with the structure and conformation of vinyl polymers, and will therefore (for reasons to be made clear in the next section) be confined to spectra of polymer solutions, since in general features providing such information cannot be resolved in solid state spectra.

The study of biopolymers has been a particularly active field of high resolution NMR spectroscopy very recently. Because of space limitations and because this area clearly deserves a review of its own, it will not be treated here.

REFERENCES

1. F.A. BOVEY and G. V. D. TIERS, Fortschr. Hochpolyrn. 3, 139 (1963).

2. D. W. MCCALL and W. P. SLICHTER, in Newer Methods of Polymer Characterization (B. KE, Ed.), Wiley-lnterscience, New York (1964).

3. F. A. BOVEY, article entitled Nuclear Magnetic Resonance, in Encyclopedia of Polymer Science and Technology, Vol. 16, Wiley-Interscience, New York (1968).

4. K. C. RAMEY andW. S. BREY,JR.,J. MacromoL Sci. C 1,263 (1967).

5. H. A. WILLIS and M. E. A. CUDBY, Applied Spectroscopy Reviews 1, 2,237 (1968).

6. J. C. WOODBREY in Vol. 3 of The Stereochemisto, ofMacromolecules (A. D. KETLEY, Ed.), Marcel Dekker, New York (1968).

7. W. P. SLICHTER, Fortschr. Hochpolym. Forsch. 1, 35 (1958).

8. J. G. POWLES, Polymer 1, 219 (1960).

9. J. A. SAUER and A. E. WOODWARD, Rev. Mod. Phys. 32, 88 (1960).

10. A.W. NOLLE and J. J. BILLINGS, J. Chem. Phys. 30, 84(1959).

11. J. G. POWLES and K. LUSZCZYNSKI, Physica 25, 455 (1959).

12. J. G. POWLES, A. HARTLAND and J. A. E. KAIL. J. Polymer Sci. 55, 361 (1961).

13. E. G. KONTOS and W. P. SLICHTER, J. Polymer Sci. 61, 61 (1962).

14. W. P. SLICHTER and D. D. DAvis, J. Appl. Phys. 34, 98 (1963).

15. W. P. SLICHTER and D. D. DAVIS, J. Appl. Phys. 35, 3103 (1964).

16. W. MCCALL and E. W. ANDERSON, Polymer4, 93 (1963).

17. J. G. POWLES, J. H. STRANGE and D. J. SANDIFORD, Polymer 4, 401 (1963).

18. J. G. POWLES, B. 1. HUNT and D. J. SANDIEORD, Polymer 5, 585 (1964).

19. W. P. SLICHTER, J. PolymerSci. C 14.33 (1966).

20. D. W. MCCALL, D. C. DOUGLASS and D. R. FALCONE, J. Phys. Chem. 71, 998 (1967).

21. W. P. SLICHTER and D. D. DAVIS, Macromolecules 1, 47 (1968).

GUERY

GUERY

Version English
Guery manufacturers of bakery equipment, pastry moulds, pastry bags, flexible silicon moulds, bread pans, elevator buckets, ducting for aspiration, ventilation, dust removal, silos.

Version French
Fabricant de matériel Boulangerie-Pâtisserie, moules à pâtisserie, poches à pâtisserie, moules souples silicone, plaques à pain, godets d’élévateur, ...

Second International Symposium on Polyvinylchloride, Lyon-Villeurbanne, France, 5-9 July 1976

Pure and Applied Chemistry

Vol. 49, Issue 5

Second International Symposium on Polyvinylchloride (PVC), Lyon-Villeurbanne, France, 5-9 July 1976

Chemical modification of PVC
T. Suzuki
p. 539 [full text - pdf 1212 kB]

Characterisation of poly(vinylchloride)
M. E. Carrega
p. 569 [full text - pdf 741 kB]

The rheology of PVC - An overview
E. A. Collins
p. 581 [full text - pdf 503 kB]

Polyvinyl chloride - Processing and structure
G. Menges and N. Berndtsen
p. 597 [full text - pdf 913 kB]

Rupture fragile des produits en PVC rigide
R. Jacob
p. 615 [full text - pdf 374 kB]

The stabilization of PVC against heat and light
H. O. Wirth and H. Andreas
p. 627 [full text - pdf 715 kB]

Combustion of PVC
M. M. O'Mara
p. 649 [full text - pdf 574 kB]

PUBLICATIONS IUPAC

Nanomechanics Lab

Nanomechanics Lab

Center of Biotechnology, TU Dresden

How does a cell work, mechanically? How do the individual components, molecules and proteins work to fulfill their cellular function?

Nanomechanics Lab

Relation Between Flow Properties, Molecular Mass and Branching of Polymer

Text taken from:

Vinogradov, Georgii Vladimirovich; Malkin, Aleksandr Yakovievich. Rheology of Polymers: Viscoelasticity and Flow of Polymers. Mir Publishers. Moscow; 1980. p. 153-154

---------

Relation Between Flow Properties, Molecular Mass and Branching of Polymer

Introduction

While considering the temperature dependence of the viscosity of linear polymers, we introduced the concept of the macromolecular segment as a molecular-kinetic unit performing elementary acts of translation in space from one equilibrium state to another. if the size of the segment is much smaller than that of the macromolecule, these transfers --the elementary acts of flow --are independent of molecular mass. However, for the macromolecule to be transferred irreversibly, it is necessary that the centre of gravity of the entire molecule be shifted as a result of the displacement of its constituent segments. But the higher the molecular mass of the polymer, i. e., the greater the number of segments in the macromolecule, the larger is the number of cooperative segment motions that must be effected for its centre of gravity to be shifted and the higher must be the viscosity.

Study of the effect of molecular mass on the flow properties of polymers is supposed to provide answers to a number of questions. How doe molecular mass affect the initial viscosity and non-Newtonian flow behavior (anomalous viscosity) of polymer? How can one compare the flow properties of polymers with the different structures of the macromolecular chain, considering that at one and the same molecular mass the chain length and flexibility may strongly differ for polymers of different nature? How does the molecular mass distribution affect the dependence of the Newtonian (initial) viscosity on molecular mass and how does the non-Newtonian flow behavior change? In evaluating the effect of molecular-mass distribution (MMD) on the flow properties of polymers there also arises the most important question: What characteristics of MMD and what values of molecular mass of polydisperse polymers about be used to compare the flow properties of various polymer?

…to be continued

Molecular Structure of Nucleic Acids: A Structure For Deoxyribose Nucleic Acid

Molecular Structure of Nucleic Acids: A Structure For Deoxyribose Nucleic Acid

See: Nature 171, 737 (1953)
(Watson and Crick: DNA)DNA

Polymer Journal: ACS Publications

Macromolecules

Vol. 40, Issue 14 July 10, 2007 Cover

On the cover: The artwork aims on describing various tools allowing the nanoscale analysis of functional polymer blends as applied for the photoactive layer of polymer solar cells. In detail, the background represents the 3D volume reconstruction of the bulk heterojunction blend MDMO-PPV/PCBM as obtained by TEM tomography (only the PCBM domains are visualized). Top left: the TEM bright-field images show the PCBM domains imbedded in the MDMO-PPV matrix. Bottom left: the AFM images show demixing of PCBM from MDMO-PPV with annealing time. Top right: the AFM tip symbolizes conductivity-AFM measurements allowing local conductivity measurements of the photoactive layer with few nanometer lateral resolution and the corresponding IV characteristics of such C-AFM measurements. See: Yang, X.; Loos, J. Macromolecules 2007, 40, 1353-1362.

Biomacromolecules
Biomacromolecules explores the interactions of macromolecules with biological systems and their environments as well as biological approaches to the design of polymeric materials. Cutting-edge research at the interface of polymer science and biological sciences.

REVIEWS ON ADVANCED MATERIALS SCIENCE
Papers on-line and free about materials science

Acta Chimica Slovenica
Acta Chimica Slovenica (ACSi) provides a forum for the publication of original and significant work in the chemical and closely related areas of research. Reviews, scientific and technical articles, and short communications are welcome.

Crystal Research and Technology
Journal for Experimental and Industrial Crystallography

Journal of Zhejiang University SCIENCE

Universidad Simón Bolívar: Clima

Plan your trip Local Radar Detailed Forecast

TOP TEN UNIVERSITIES IN THE WORLD

According to The Times Higher Education Supplement, 2006:

Rank	University
1	Harvard University
2	University of Cambridge
3	University of Oxford
4	Massachusetts Institute of Technology
5	Yale University
6	Stanford University
7	California Institute of Technology
8	University of California at Berkeley
9	Imperial College London
10	Princeton University

Taken from: http://i.cs.hku.hk/~tse/topten.html#World
(August 2007)

Massachusetts Institute of Technology (MIT) and Polymer Science

See: DSC of PCL polymer

and
Massachusetts Institute of Technology (MIT) and Polymer Science
... Open Course Ware (MIT)