Papers by Author: Hong Yan Tang

Abstract: A novel idea to prepare Polymethacrylimide (PMI) foam is presented in this paper, in which PMI foam was prepared by two steps, the butyl methacrylate (BMA)/methacrylamide (MAM) copolymer was formed using solution polymerization through free radical copolymerization, and then PMI foam was produced through the BMA/MAM copolymer foaming. Mechanism of polymerization reactions was analyzed. The BMA/MAM copolymer and PMI foam were investigated by Fourier transform infrared spectroscopy. It showed disappearance of the primary amide and appearance of the formation of PMI foam, which was in accordance with the mechanism of polymerization reactions. The polarizing micrograph showed PMI foam was highly transparent and closed cell. Differential scanning calorimetry and thermogravimetric analysis results showed PMI foam had excellent thermal stability below ~255°C because of the presence of the imide ring.

Abstract: Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.