Viscoelastic behavior of styrene/n-butyl-methacrylate/potassium methacrylate polymers

2007 ◽  
Vol 45 (1) ◽  
pp. 139-151 ◽  
Author(s):  
Peter F. Erhardt ◽  
James M. O'Reilly ◽  
W. Conrad Richards ◽  
Meurig W. Williams
Keyword(s):  
Viscoelastic Behavior ◽  
Butyl Methacrylate ◽  
Methacrylate Polymers

Structure and Dynamics of Syndiotactic Poly(n-Butyl Methacrylate) Near the Glass Transition

1990 ◽  
Vol 215 ◽  
Author(s):  
G. D. Paiterson ◽  
P. K. Jue ◽  
J. R. Stevens
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Relaxation Function ◽  
Butyl Methacrylate ◽  
Time Range ◽  
Pure Liquid ◽  
Relaxation Rates ◽  
Relaxation Functions ◽  
Methacrylate Polymers

AbstractAn optically homogeneous sample of highly syndiotactic poly(n-butyl methacrylate) (PBMA) has been prepared. The glass transition temperature was observed to be Tg=55C. Measurements of the scattered intensity of the sample followed the expected behavior for a pure liquid above Tg. The intensity rose as the sample was cooled further towards the glass transition temperature for atactic PBMA. These results illuminate the importance of regions of different stereoisomers in methacrylate polymers. Measurements of the Rayleigh- Brillouin spectrum were carried out from -15 to 130 C. The ratio of the the central peak intensity to the Brillouin intensities at temperatures above Tg was consistent with a viscoelastic liquid and had a magnitude near 3. The Brillouin linewidth remained large near Tg. and decreased continuosly with no apparent change in slope in the glass transition region. The presence and importance of rapid motions in polymers near the glass transistion is demonstrated by these results. Slowly relaxing density fluctuations near Tg. were measured by photon correlation spectroscopy. Relaxation functions were obtained from 10−6 to 10 s. Average relaxation times <τ> were obtained from the integral of the relaxation function and were found to follow the relation <τ>=Aexp(B/(T−T0)), where for our sample B=2940K and T0=273K. The observed relaxation function decayed over a wider time range as the sample was cooled. Quantitative analysis of this effect using the Williams-Watts empirical function yielded a decrease in β from 0.35 at 90 C to 0.18 at 65 C. The relaxation functions were also analyzed to give a distribution of relaxation rates. The observed distributions were bimodal at 70 and 80 C. The two features behaved in a manner consistent with the primary and secondary relaxations observed for methacrylate polymers by other techniques.

scholarly journals Insertion of Degradable Thioester Linkages into Styrene and Methacrylate Polymers

2022 ◽  
Author(s):  
Matthew Rix ◽  
Samuel Higgs ◽  
Eleanor Dodd ◽  
Simon Coles ◽  
Nathaniel Bingham ◽  
...  
Keyword(s):  
Free Radical ◽  
Uniform Distribution ◽  
Radical Polymerization ◽  
Degradation Product ◽  
Free Radical Polymerization ◽  
Butyl Methacrylate ◽  
Ether Cleavage ◽  
Tert Butyl ◽  
Methacrylate Polymers ◽  
First Time

The thionolactone 3,3-dimethyl-2,3-dihydro-5H-benzo[e][1,4]dioxepine-5-thione (DBT) is shown to homopolymerize and, for the first time, copolymerize with styrene and methacrylates, introducing degradable thioester backbone functionality. The rapid copolymerization with styrene was exploited to produce copolymers through free-radical polymerization in a starve-fed semi-batch setup. The copolymerization of DBT with tert-butyl methacrylate under RAFT conditions was hypothesized to involve selective retardation of DBT-terminal chains that led to a more uniform distribution of degradable thioester linkages between chains. Surprisingly, the aminolysis of DBT homopolymers was accompanied by the intramolecular ether cleavage within the primary degradation product leading to the formation of 2,2-dimethylthiirane and salic-ylamides.

Viscoelastic behavior of poly(butyl methacrylate) densely grafted on silica nanoparticles

2011 ◽  
Vol 60 (8) ◽  
pp. 1194-1200 ◽  
Author(s):  
Kenichi Hayashida ◽  
Hiromitsu Tanaka ◽  
Osamu Watanabe
Keyword(s):  
Silica Nanoparticles ◽  
Viscoelastic Behavior ◽  
Butyl Methacrylate

Polarized Light-Induced Anisotropy in Polymer Films Doped with Az Dyes in the Photostationary State Studied by IR Spectroscopy

1997 ◽  
Vol 488 ◽  
Author(s):  
K. Tawa ◽  
K. Kamada ◽  
T. Sakaguchi ◽  
K. Ohta
Keyword(s):  
Ftir Spectroscopy ◽  
Polymer Films ◽  
Dynamical Behavior ◽  
Polarized Light ◽  
Butyl Methacrylate ◽  
Absorption Bands ◽  
Photostationary State ◽  
Methacrylate Polymers ◽  
Polarized Ftir ◽  
Polarized Ftir Spectroscopy

AbstractThe anisotropy induced in a series of methacrylate polymers doped with Disperse Orange 3 (DO3, NO2-phenyl-N=N-phenyl-NH2) was investigated by polarized FTIR spectroscopy. Three kinds of methacrylate polymers with different glass transition temperature (Tg), poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and poly(butyl methacrylate) (PBMA), were used as polymer matrices. Observed infrared absorption bands of DO3 in the polymer films were assigned to symmetric (NO2s) and antisymmetric (NO2as) stretching modes of NO2, and the C-N stretching mode of C-NH2 (C-N). The infrared dichroism was observed in these bands under the irradiation. The orientation factors, Kzfn, (f=x, y, z, n=trans, cis), for both isomers of DO3 were determined in the photostationary stite for every polymer matrix. The factors indicate that it is difficult for NO2 group to move in the PMMA during trans-cis-trans isomerization and that it is difficult for NH2 group to move in the PBMA. The dynamical behavior of DO3 molecules which depends on the kind of polymers could be interpreted from orientation factors. This study shows that polarized FTIR spectroscopy is one of the most powerful methods available to analyze the physical mechanisms of photoinduced anisotropy.

Nonlinear Viscoelastic Finite Element Analysis of Adhesive Joints

1988 ◽  
Vol 16 (3) ◽  
pp. 146-170 ◽  
Author(s):  
S. Roy ◽  
J. N. Reddy
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Viscoelastic Behavior ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Element Analysis ◽  
Adhesively Bonded Joints ◽  
Nonlinear Viscoelastic ◽  
Structural Failures ◽  
Updated Lagrangian

Abstract A good understanding of the process of adhesion from the mechanics viewpoint and the predictive capability for structural failures associated with adhesively bonded joints require a realistic modeling (both constitutive and kinematic) of the constituent materials. The present investigation deals with the development of an Updated Lagrangian formulation and the associated finite element analysis of adhesively bonded joints. The formulation accounts for the geometric nonlinearity of the adherends and the nonlinear viscoelastic behavior of the adhesive. Sample numerical problems are presented to show the stress and strain distributions in bonded joints.

Sign in / Sign up

Export Citation Format

Share Document