Blends of cellulose with nylon 6 and poly(ε‐caprolactone) prepared by a solution‐coagulation method

Abstract

AbstractConditions are described for preparing blends of cellulose with nylon 6 (Ny6) and poly(ε‐caprolactone) (PCL) from solutions in N,N‐dimethylacetamide (DMAc)– lithium chloride (LiCl) by coagulation in a non‐solvent. The binary blend films of both series, obtained over a wide composition range (10/90–90/10) from mixed polymer solutions, were characterized by wide‐angle x‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and dynamic mechanical measurements. In the two series of cellulose blends the other component (Ny6 or PCL) was crystalline at every composition, but there was some degree of disproportional reduction of the crystallinity with an increase in cellulose content. From the dynamic Mechanical testing, the cellulose/Ny6 blends were found to be almost immiscible, although the possibility of a certain level of partial miscibility in the non‐crystalline regions was admitted at high cellulose concentrations (>80 wt%). For the cellulose/PCL blends, it was found that there was evidently an amorphous phase where a limited amount of cellulose could be well mixed with PCL. A relatively large shift of the midpoint in the PCL glass transition region to the higher temperature side was noted at the compositions containing 20 and 30 wt% cellulose. This effect is discussed in relation to the requirement of an optimum balance in the density of the interacting hydroxyl and ester groups, for obtaining true miscibility of cellulosics with PCL at the molecular level.