Determination of Small-Amount Polypropylene in Imported Recycled Polyethylene/Polypropylene Blends by Fourier Transform Infrared SpectroscopyShujun Dai, Chuan Luo, Chao Zhang, Hao Wang, Yin Zhang and Lifeng YuanE3S Web Conf., 261 (2021) 02067DOI: https://doi.org/10.1051/e3sconf/202126102067