Preparation of a structured acrylic impact modifier and its application in toughening polyamide 6

Abstract

A series of poly(n‐butyl acrylate)/poly(methyl methacrylate‐co‐acrylic acid), i.e., poly(BA/MMA‐co‐AA), core‐shell structured modifiers with different contents of crosslinking agent allyl methacrylate and functional monomer were prepared, and its effects on mechanical properties of polyamide 6 (PA 6) blends were investigated. The modifiers were prepared at a solid content of 50 wt% by a seeded emulsion polymerization. Dynamic light scattering measurement showed that the particle grew without significant secondary nucleation occurring. The morphology was confirmed by means of transmission electron microscopy. Scanning electron microscopy was used to observe the morphology of the fractured surfaces. The dynamic mechanical analysis measurements indicated that the appearance of two merged transition peaks and the magnitude of the loss peak of PA 6 matrix with the addition of PBMA core‐shell modifier in the PA 6/PBMA blends were responsible for the improvement of PA 6 toughness. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

Investigation of grain competitive growth during directional solidification of single-crystal nickel-based superalloys

“…This illustrated that the misaligned grains would have great growth advantage and can overgrow the well-aligned grains under special conditions. The findings of Zhou and our previous research [14,20] had validated this discovery. In order to explore the mechanism of competitive grain growth in DS, several important relationships of grain competitive growth have been analyzed as following.…”

“…5a, there was another different result for the grain competitive growth. Grain B may be overgrown by grain A, which has been confirmed by most researchers and our previous experimental results [20]. Therefore, the two grains could overgrow each other under different conditions for this converging relationship.…”

Tunable mechanical properties of core‐shell polymers of poly(hexyl methacrylate) and poly(methyl methacrylate) by semicontinuous heterophase polymerization

“…Zhao et al prepared PBA‐poly(methyl methacrylate‐co‐acrylic acid) (PBMA) core/shell particles with narrow size distribution by semi‐continuous emulsion polymerization under monomer‐starving conditions to toughen a polyamide 6 (PA‐6) matrix, and found that the PA‐6‐PBMA blends were significantly tougher due to the good dispersion and adhesive interface between PBMA and PA‐6 .…”

Fabrication of robust polyamide 6 with local cross‐linked structure via dynamic vulcanization

“…Toughening modification of PA6 has always been a research hotspot because PA6 is sensitive to notch, which leads to low impact strength. To enhance its toughness, the utilization of tougheners is a common and effective method, such as core-shell particles, [7][8][9][10] rubbers, [11][12][13][14] and thermoplastic elastomers, [15][16][17] but the rigidity of modified PA6 is prone to be compromised. For example, with the addition of polyolefin elastomer-graft-maleic anhydride (POE-MAH), the modified PA6 showed a nearly 11-fold increase in impact strength compared to the original PA6, meanwhile, the yield stress dropped by nearly 50%.…”