Compatibility of poly(ϵ‐caprolactone) (PCL) and poly(styrene‐co‐acrylonitrile) (SAN) blends. I. Blends containing SAN with 24 wt% acrylonitrile

Abstract

SynopsisPolymer blends of poly(ecapro1actone) (PCL) and poly(styrene-co-acrylonitrile) (SAN), containing 24 wt 9% acrylonitrile (AN), were prepared, and their transition behavior was examined by thermal analysis and dynamic mechanical testing. The blends were judged to be compatible on the basis of the presence of a single, compositionally dependent glass transition. The results of thermal treatment upon blend glass transition behavior and the dependence of thermal history upon the crystallization of semicrystalline PCL were also studied. The crystallization of PCL from SAN/PCL blends was found to be retarded by the presence of SAN, and crystalline PCL was found to exist only in blends containing a high PCL concentration. Blends which do not contain crystalline PCL were transparent, and their glass transition behavior can be correlated by the Gordon-Taylor equation. Phase separation, which was characterized by lower critical solution temperature (LCST) behavior, was found to occur when blends were heated to elevated temperatures. SUMMARYPolymer blends of PCL and SAN, which contains 24 wt 96 AN, show a single glass transition by both DSC and dynamic mechanical measurements over the entire blend composition range. This is evidence that the amorphous phase in these blends is a single phase containing a mixture of both polymers. The glass transition of blends was found to be dependent on the thermal treatment of the samples, i.e., on the extent of crystallization of PCL from the compatible blend. Crystallization of PCL in a blend extracts material from the amorphous regions and hence changes the composition in the amorphous phase. For samples free of PCL crystals, the glass transition temperatures were able to be correlated as a function of composition by the Gordon-Taylor equation.Crystallization of PCL is retarded and the T, of PCL is depressed by the addition of SAN in the blend. The onset temperature of a PCL crystallization exotherm on a DSC thermogram, T,, for the reheating scan after quenching from the molten state, increases with increasing SAN concentration in the blends. These results provide further evidence to confirm compatiblity for this blend.A liquid-liquid-type phase separation at high temperature because of the existence of a LCST was also observed for this compatible system. The cloud point curve was found to be skewed toward high PCL concentrations due to differences in the molecular weight of blend components. A preliminary phase

Effect of the type of SAN in SAN/CPE blend: Morphology, mechanical, and rheological properties

“…Therefore, it is very imethylene-propylene-diene terpolymer. portant for the development of rubber-modified SAN can readily blend with a number of other polymers to find how to improve the impact polymers including poly(1-caprolactone), 3,4 polystrength without deterioration of the other propcarbonate, [5][6][7][8][9] poly(vinylidenefluoride), 10 nylon, …”

Biodegradable polymer blends and composites: An overview

“…PCL/SAN blends. Various works reporting prepa ration and application of PCL/SAN polymer blends have been documented since 1982 [84][85][86][87]. The com patibility of PCL/SAN polymer blends has been inves tigated by various research groups.…”

“…The com patibility of PCL/SAN polymer blends has been inves tigated by various research groups. Chiu and Smith [84] have reported compatibility of PCL/SAN blends over the entire range of blend compositions using DSC and a dynamic mechanical analyzer. They have found that PCL is compatible with SAN containing AN con tents which are greater than 8 wt % but less than 28 wt %.…”

Mechanical Properties of Styrene Acrylonitrile and Chlorinated Polyethylene Blends: Effect of Chlorine Content

“…CPE can be blended as impact modifier for brittle SAN to improve mechanical properties. Many studies have been reported to improve the compatibility that results the final mechanical properties of SAN by blending with other polymers including nylon [5], poly(phenylacrylate) [6], polyvinyl chloride (PVC) [7,8], poly carbonate [3,9], poly(caprolactone) [10][11][12], polypropylene [13]. Compatibility is a technical term defining the property profile of the blend in view of a certain application and, it is a function of the interaction of polymer molecules in the blend and can be detected using various methods including mechanical and interfacial measurements.…”