Effect of Bimodality on the Adhesive Properties of Pressure Sensitive Adhesives: Role of Bimodal Particle Size and Molecular Weight Distributions

2010 ◽  
Vol 49 (16) ◽  
pp. 7303-7312 ◽  
Author(s):  
Gabriela E. Fonseca ◽  
Timothy F. L. McKenna ◽  
Marc A. Dubé
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Adhesive Properties ◽  
Pressure Sensitive Adhesives ◽  
Molecular Weight Distributions ◽  
Pressure Sensitive ◽  
Weight Distributions

Titanium pyridyl-phosphinimide complexes — Synthesis, structure, and ethylene polymerization catalysis

2006 ◽  
Vol 84 (5) ◽  
pp. 755-761 ◽  
Author(s):  
Chad Beddie ◽  
Pingrong Wei ◽  
Douglas W Stephan
Keyword(s):  
Molecular Weight ◽  
Key Words ◽  
Ethylene Polymerization ◽  
Olefin Polymerization ◽  
Polymerization Catalysts ◽  
Pyridyl Group ◽  
Molecular Weight Distributions ◽  
Polymerization Catalysis ◽  
Weight Distributions

A series of Ti–pyridyl-phosphinimide complexes of the form Cp′TiX2[NPR2(2-CH2Py)] (Cp′ = Cp, Cp*, R = i-Pr, t-Bu, X = Cl, Me) have been prepared and characterized. These complexes generate ethylene polymerization catalysts upon activation with MAO or B(C6F5)3. The resulting polymers exhibit broad molecular weight distributions. The role of the pyridyl group is discussed in light of stoichiometric reactions of CpTiCl2[NPR2(2-CH2Py)] with B(C6F5)3.Key words: phosphinimide complexes, pyridyl-phosphinimides, olefin polymerization.

Molecular Weight Dependence of Relaxation Spectra of Amorphous Polymers in the Rubbery Region. VIII. Comparisons of Experimental Relaxation Spectra of Commercial Synthetic Rubbers with those Estimated from Molecular Weight Distributions

1967 ◽  
Vol 40 (2) ◽  
pp. 484-492 ◽  
Author(s):  
Genichi Yasuda
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Mechanical Relaxation ◽  
General Validity ◽  
Relaxation Spectra ◽  
Molecular Weight Distributions ◽  
Synthetic Rubber ◽  
Weight Distributions

Abstract Synthetic rubber of different species, types, and degrees of mastication were used to examine the general validity of the proposed relationship between mechanical relaxation spectra in the rubbery region and molecular weight distribution. Results show that the proposed relationship can be well used to discuss quantitatively the role of molecular weight distribution in the theoretical behavior of a raw rubber while being processed.

Adhesion mechanisms at soft polymer interfaces

2007 ◽  
Vol 366 (1869) ◽  
pp. 1425-1442 ◽  
Author(s):  
Liliane Léger ◽  
Costantino Creton
Keyword(s):  
Adhesive Layer ◽  
Polymer Chains ◽  
Polymer Interfaces ◽  
Adhesive Failure ◽  
Adhesive Properties ◽  
Extraction Mechanism ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive ◽  
Soft Polymer

Based on several significant examples, we analyse the adhesion mechanisms at soft polymer interfaces with a special emphasis first on the role of connector molecules, that is, polymer chains bound to the interface and which transmit stress through a stretching and extraction mechanism, and second on the necessary relay that must be taken by additional dissipation mechanisms acting at larger scales if one wants to reach typical fracture toughnesses in the range of a few 10 J m −2 . Examples of such bulk dissipation mechanisms will be discussed for interfaces between polymer melts and for pressure-sensitive adhesives in contact with a solid surface. We shall particularly point out the fact that the level of adhesion results from a competition between adhesive failure usually driven by both the interactions and the friction properties of the interface and bulk strong deformations which take place in the bulk of the adhesive layer. Controlling the friction properties of the interface then becomes a tool to finely tune adhesive properties.

Sign in / Sign up

Export Citation Format

Share Document