Thermoplastic Modification of Polyvinyl Alcohol for Preparing Water-Splittable Sea-Island Fiber

Polyvinyl alcohol (PVA) is a type of water-soluble polymer that is a candidate for 'sea' polymer to prepare sea-island fibers in industry. In this study, two types of polyols (sorbitol ether and neopentyl glycol) were mixed in different proportions and used to prepare thermoplastic PVA (TPVA) as a compound plasticizer. When the plasticizer was introduced, a blue shift occurred on the characteristic band of hydroxyl in the Fourier transform infrared spectroscopy (FTIR) pattern. The melting temperature (Tm) of the corresponding TPVA decreased, and their initial decomposition temperature (Td) in-creased to some degree. The addition of compound plasticizer made PVA show an improved Td up to 273.1 degrees C. Moreover, it led to an increment of the melting flow index and improved the resistance to oxidation at a temperature higher than 200 degrees C. The increased spinnability enabled TPVA in PVA-PLA sea-island fiber making. PLA superfine fibers were obtained after splitting in water at 95 degrees C for just 3 min.