High Impact Polymer Alloy

Abstract

We have already represented that high impact mechanism of polyketone/polyamide alloy (PK/PA) is enhanced by the moisture absorption. It was thought the high impact mechanism depends on ductility caused by the moisture absorption of the alloy. This time we have investigated the nano-meter level phase separation structure of PK/PA alloys by using a TEM, an EELS and a 3D-TEM observation. It is found that the PK rich phase and the PA rich one form their co-continuous structure. Surprisingly, the three-dimensional lamella network structure is extended in the PK rich phase. Next, we have carried out SAXS measurements to evaluate lamella network structure. Moreover, the interaction and the mobility of PK and PA molecular chain of the wet and dry polymer alloy have been investigated by using solid-state high resolution NMR techniques. It was found that the moisture absorption enhances the molecular mobility of PA, and flexibility is given to the polymer alloy. The above-mentioned results revealed that the co-continuous structure and the higher-order structure are closely related to the impact properties.

High Impact Properties of Polyketone/Polyamide-6 Alloys Induced by Characteristic Morphology and Water Absorption

“…However, a lamellar-like structure was detected even in the K90A10 alloy in the 3D-TEM image, albeit not clearly (Figure S2(c) the Supporting Information). 4,5 This indicates that PA plays an important role in forming the lamellar-like structure. The results of a previous 3D-TEM study suggested that there are characteristic spherical domains on a scale of 50-200 nm in the PK-rich alloys, K90A10 or K80A20 (Figure S2 in the Supporting Information).…”

“…The results of a previous 3D-TEM study suggested that there are characteristic spherical domains on a scale of 50-200 nm in the PK-rich alloys, K90A10 or K80A20 (Figure S2 in the Supporting Information). 4,5 Figure 4b shows that there are cocontinuous spherical domains in the K60A40 alloy. These cocontinuous spherical domains of ca.…”

“…The occurrence of a weak interaction between PK and PA was revealed by analyzing the Raman spectra. 4,5 To clarify which polymer forms the lamellar-like structure, we examined an electron energy loss spectroscopy (EELS) image of the K60A40 alloy. Figure 4c shows an EELS image that indicates the location of nitrogen atoms; the green color represents the nitrogen-rich region.…”

“…The results of our previous 3D-TEM study also showed similar lamellar-like images even for PA-rich alloys, but the images were blurred (Figure S2(a) in the Supporting Information). 4,5 The characteristic spherical and cylindrical structures as shown in Figure 4b are formed by the connection of both amorphous phases of PA and PK. The 3D-TEM images show that any numbers of PK lamellae are inserted in the cylindrical domains.…”

“…We have previously reported the relationship between impact property and water content based on Charpy impact test results, and that a weak interpolymer interaction between PK and PA surfaces was confirmed by the compositional dependence of Raman spectra. [3][4][5] Preliminary studies of the PK/PA alloys were also conducted by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). The TEM measurements revealed that the PK/PA alloys show a characteristic microstructure consisting of the PA-rich phase and a lamellar network of the PK-rich phase, which we call a cocontinuous nanolayer.…”