Compatibilizers made from Copolymers that Exhibit Strong Interactions

1996 ◽  
Vol 461 ◽  
Author(s):  
Barry J. Bauer ◽  
Da-Wei Liu

ABSTRACTRandom copolymers of poly(methyl methacrylate-d8) (PMMA) and poly(methacrylic acid) (PMAA) were synthesized and blended with polyethylene oxide (PEO), and SANS was used to estimate the strength of interaction between the various polymer pairs. The addition of PMAA greatly reduced the scattering of the blend, giving a large negative Flory-Huggins interaction parameter. Copolymers of the type PMAA-g-PS, PMAA-r-PS, PMMA-g-PS, and PMMA-r-PS (g = graft, r = random) were used as compatibilizers for the melt blending of mixtures containing 80% PS and 20% PEO. Random copolymers containing half PMMA and half PS or half PMAA and half PS were ineffective compatibilizers while graft copolymers of these polymers produced a much finer dispersion of PEO in PS when blended at 190°C. Graft copolymers made with 90% PS were different, however, with PMMA grafts having only a small effect, while PMAA grafts having a large effect. Random and graft copolymers of PS and PMMA were also used to compatibilize blends of PS and PMMA. The results were similar to the same compatibilizers with blends of PS and PEO, with the graft copolymer causing a finer dispersion.

2021 ◽  
Vol 10 ◽  
pp. 27-36
Author(s):  
K. V. Allahverdiyeva ◽  

The influence of the concentration of finely dispersed aluminum and compatibilizer on the resistance to peeling of aluminum foil from the surface of a composite based on low density polyethylene and high density polyethylene is considered. To improve the compatibility of the filler with the polymer matrix, a compatibilizer was used, which is a graft copolymer of polyethylene of various grades with methacrylic acid and maleic anhydride. Copper and aluminum foil was used as a substrate. It is shown that the introduction of a compatibilizer into the composition of aluminum-filled composites improves their peeling resistance. It has been found that if an aluminum filled compatibilizer is used directly as an adhesive, then the peeling resistance of copper and aluminum foil is significantly increased. Graft copolymers of polyethylene with maleic anhydride have the highest peel resistance values. The results of the study of the influence of the pressing temperature on the type of adhesive failure are presented. It is shown that with an increase in the pressing temperature, a mixed type of adhesive destruction is observed. It has been experimentally proved that, in percentage terms, the cohesive type of fracture prevails in composites where graft copolymers are used as a polymer matrix. It was found that a 100 % cohesive type of fracture is observed in foil-clad composites pressed at a temperature of 190 °C, where a graft copolymer of polyethylene with methacrylic acid or maleic anhydride is used as an adhesive.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Thi Nhan Nguyen ◽  
Hieu Nguyen Duy ◽  
Dung Tran Anh ◽  
Thuong Nghiem Thi ◽  
Thu Ha Nguyen ◽  
...  

In this study, we investigated the improvement of the thermal and mechanical properties of Vietnam deproteinized natural rubber (DPNR) via graft copolymerization of methyl methacrylate (MMA). The graft copolymerization was achieved successfully in latex stage using tert-butyl hydroperoxide (TBHPO) and tetra-ethylenepentamine (TEPA) as radical initiators at 30°C. By grafting with various MMA feeds and initiator concentration of 6.6×10−5 mol/g-rubber, the highest grafting efficiency and conversion were achieved at MMA of 15 wt.% per kg of rubber, 68% and 90%, respectively. The structure of grafted copolymers was characterized by 1H NMR, FTIR-ATR, and GPC, and thermal properties were investigated through DSC and TGA measurements. These showed that graft copolymers were more stable and rigid than DPNR. Storage modulus (G′) of graft copolymer was found to double that of DPNR, which contributed to the formation of graft copolymer. After sulfur vulcanization, the mechanical properties of DPNR-graft-PMMA, such as tensile strength, tear strength, and hardness, were improved significantly. Curing behaviors of the graft copolymers were found to be remarkably better than virgin DPNR.


1975 ◽  
Vol 13 (12) ◽  
pp. 725-729 ◽  
Author(s):  
J. H. G. M. Lohmeyer ◽  
G. Kransen ◽  
Y. Y. Tan ◽  
G. Challa

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Fatima Zohra Sebba ◽  
Seghier Ould Kada ◽  
Mohamed Benaicha ◽  
Nerjesse Nemiche

AbstractIn this study, 2-oxopropylmethacrylate-terminated poly(N-vinyl-2- pyrrolidone) is produced by cationic polymerization using HClO4 as an initiator. Termination (end capping) step is accomplished using 2- hydroxypropylmethacrylate (2HPMA) and the polymer product has different chain lengths of molecular weight averages ranging from 672 to 3049 g/mol. The study also synthesised amphipathic graft copolymers having hydrophobic poly(α- methylstyrene) as a backbone chain and hydrophilic poly(N-vinyl-2-pyrrolidone) (PVP) as side chains of various lengths. The copolymer synthesis was accomplished by free radical copolymerization of ω-oxopropylmethacrylate PVP in the presence of α-methyl styrene initiated with benzoyl peroxide. Measurements of the dynamic viscosity of the polymer solution (20% weight of macromonomers in ethanol) show that the viscosity is proportional to the average molecular weights M̅n . However, a reverse behaviour of the viscosity variation with regard to M̅n is observed for graft copolymer samples. The viscosity variation with respect to the graft copolymer mass must be due to steric effects, which are strongly pronounced in grafted copolymer chains. Appearance of the number of side chains attached to poly(α-methylstyrene) backbone reveals that the grafting reaction has occurred with good efficiency.


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