**6. References**

Alfrey, T. & Doty, P. (1945). J. Appl. Phys., Vol. 16, 700


to TSSR measurements and from the initial slope of the TSSR stress temperature curves the crosslink densities of the samples were determined, by considering the entropy effect. Additionally, TPV based on EPDM/HDPE which was designed for hard/soft - combinations with HDPE and UHMW-PE. Due to better compatibility of EPDM and HDPE, the phase morphology and also the properties differ from EPDM/PP based TPV. From the results of TSSR measurements the differences with respect to rubber elasticity and heat resistance be-

Although TSSR tests are relatively fast and easy to perform, an accelerated test procedure has been developed for rapid determination of crosslink density of TPV. Based on a theoretical approach a basic equation has been developed to separate the phenomenon of stress relaxation from the initial part of the experimentally observable stress - temperature curve. Thus, reliable

Anthony, R. L., Caston, R. H. & Guth, E. (1942). Equations of State for Natural and Synthetic

Barbe, A., Bökamp, K., Kummerlöwe, C., Sollmann, H., Vennemann, N. & Vinzelberg, S.

Bittmann, E. (2004) Elastisch und maßgeschneidert. *Kunststoffe,* Vol. 94**,** No. 12,

Dickens, B. (1982) Thermal-Degradation Study of Isotactic Polypropylene Using Factor-Jump Thermogravimetry. *J. Polym. Sci. Pol. Chem.*; Vol. 20, No. 5, pp. 1169-1183 Eisele, U. (1979) Einflüsse der Molekülstruktur auf Verarbeitungs- und Festigkeitseigen-

Ferry, J. D. (1980). *Viscoelastic Properties of Polymers (Third Edition),* John Wiley & Sons, ISBN

Gent, A. (Ed.) (2001). *Engineering with Rubber: How to Design Rubber Components (Second* 

Ghosh, P., Chattopadhyay, B. & Sen, A.K. (1994) Thermoplastic elastomers from blends of

Grinberg, F. , Garbaraczyk, M. & W. Kuhn (1999) Influence of the cross-link density and the

Holden, G., Kricheldorf, H. R. & Quirk, R. P. (Eds.) (2004) *Thermoplastic Elastomers (Third* 

*Edition)*, Carl Hanser Verlag, ISBN 3-446-22375-4, Munich

(2005) Investigation of Modified SEBS-Based Thermoplastic Elastomers by Temperature Scanning Stress Relaxation Measurements. *Polymer Eng. and Science*, Vol. 45,

schaften von hauptvalenzmäßig vernetzten Elastomeren. *Progr. Colloid & Polymer* 

polyethylene and ethylene-propylene-diene rubber: influence of vulcanization technique on phase morphology and vulcanizate properties. *Polymer*, Vol. 35**,** pp.

filler content on segment dynamics in dry and swollen natural rubber studied by the NMR dipolar-correlation effect. *J. Chem. Phys.*, Vol. 111, No. 24, pp. 11222-

values of crosslink density can be obtained even at strongly reduced test duration.

Rubberlike Materials. I. *J. Phys. Chem.,* Vol. 46, pp. 826 - 840

Alfrey, T. & Doty, P. (1945). J. Appl. Phys., Vol. 16, 700

come clearly obvious.

**6. References** 

pp. 1498 – 1507

pp. 109 – 111

3958-3965

11231

*Sci*., Vol. 66, pp. 59 - 72.

0-471-04894-1, New York

*Edition),* Hanser, ISBN 3-446-21403-8, Munich


**18** 

*Romania* 

**New Thermoplastic Ionic Elastomers Based on** 

Ionic thermoplastic elastomers or ionomers are copolymers involving a major non-polar constituent (which can be crystallized or not) and a minor ionizable constituent, partly or entirely neutralized with mono- and divalent inorganic ions as a salt at a concentration not

In order to obtain ionic thermoplastic elastomers, one or more of the techniques listed

a. Synthesis of elastomers containing ionizable monomers or just preparing the thermoplastic ionic elastomers on the same equipment where polymerization, copolymerization or polycondensation of the basic monomers in the polymer chain are performed, but adding small amounts (5-7%) of other monomers resulting in ionic or

b. Converting chemically some elastomers containing double bonds in their

c. Processing elastomers containing ionizable groups with metal salts, metal alkali or metal oxides which can react with the functional groups in the ionizable groups, thus yielding ionic ranges; fillers, ionic plasticizers, polyolefins, antioxidants etc. can be also added in order to obtain ionic thermoplastic elastomer compounds with a large variety

The ionic elastomer compounds resemble highly with the traditional rubber compounds but there are some differences. Because the former are thermoplastics, there is no curing stage and, therefore, no sulfur and vulcanization accelerators or peroxides are added. Another significant difference is the use of an ionizing agent - ionic plasticizer in preparing ionic thermoplastic elastomers. It plays the role of promoting the ionic break-up of the ionic interactions at high temperatures to enable the shearing flow of the compound; at room

exceeding 10 mol % (Andrei & Dobrescu, 1987; Stelescu, 2011).

of applications depending on their composition (Zuga, 2005).

ionizable groups in the polymer chain.

**1. Introduction** 

bellow can be used:

macromolecules.

Corresponding Author

 \*

**MA-g-EPDM with Advanced Characteristics** 

Anton Airinei1, Mihaela Homocianu1,

 Daniel Timpu1 and Daniela Maria Stelescu2,\* *1"Petru Poni" Institute of Macromolecular Chemistry, Iasi,* 

> *2National Research and Development Institute for Textile, Leather and Footwear Research, Bucharest,*

Zhao, F., Ping, Z., Zhao, S., Jian, Y. & Kuhn, W. (2007) Characterization of Elastomer Networks by NMR Parameters Part II. *Kautsch. Gummi Kunstst.,* Vol. 60, No. 12, pp. 685 - 688
