Photoreactive particle prepared from natural rubber and 1,9-nonandioldimethacrylate

Photoreactive particle was prepared by graft copolymerization of 1,9-nonandioldimethacrylate (NDMA) onto deproteinized natural rubber (DPNR) particles in latex stage. First, NDMA was mixed with α-cyclodextrin (α-CD) as a coupling agent to form an inclusion complex to stabilize a carbon-carbon double bond of NDMA as a bifunctional monomer. Second, the inclusion complex was graft-copolymerized onto natural rubber (NR) in latex stage with potassium persulfate (KPS) as an initiator, after deproteinization with urea in the presence of surfactant. A terminal vinyl group of NDMA was used for the graft copolymerization, while the other remained in the resulting polymer, due to the coupling effect of the α-CD. The products, after washing α-CD out, were characterized by FTIR, X-ray diffraction (XRD), ¹H NMR and solid-state ¹³C NMR measurements. The amount of residual carbon-carbon double bond after graft copolymerization was investigated in relation to the amount of rubber and reaction temperature.