The chemical structure of the NR-g-CSt/MENR blend was elucidated by CP/MAS solid state13C NMR(Chemagenetics CMX 100). Measurement was conducted under astatic field strength of 2.3 T (100 MHz, 1 H) at 20 ± 1◦C. The con-tact time for CP was 1 ms with a proton 90◦pulse of 5.5 s and adecouping power of 75 kHz. The MAS speed was 3 kHz and the delaytime after acquisition of the FID signal was 4 s. The chemical shiftswere calibrated by using an external hexamethyl benzene standard.In addition, the NR-g-CSt and NR-g-CSt/MENR blends were alsoanalyzed by X-ray diffractometry (XRD) using a WI-RES-XRD-001,Philips X’Pert MPD under the following conditions: Nickel filteredCu K radiation ( = 0.15406 nm) at a current of 25 mA and a volt-age of 35 kV. The scanning rate was 4◦/min in an angle range of5–90◦(2). The molecular weights of the NR and NR-g-CSt weredetermined using a Waters liquid chromatography apparatus withUV and IR detectors. Terahydrofuran was employed as the elu-ant and a flow rate of 10 cm3/min was used. The apparatus wascalibrated by mono-dispersed polystyrene (PS) calibration stan-dards. Thermo Gravimetric Analyses (TGA) was performed usinga TGA7, PerkinElmer instrument. A 10–20 mg sample was placedin a platinum pan and analyses were carried out under nitro-gen and oxygen atmospheres (gas flow = 100 ml/min), at a heatingrate of 10◦C/min−1, in a temperature range of 50–1300◦C. Frictionforce imaging and friction force measurements were conductedin contact mode with a scanning angle of 90◦to the long axis ofthe cantilever beam at a scanning velocity of 1 Hz. A standard V-shape silicon nitride cantilever with a square-pyramidal tip (VeecoProbes, Inc.) was used. The manufacturer’s nominal values for thecantilever length and spring constant were 125 mm and 0.38 N/m,respectively. The particle sizes of the three samples (MENR, NR-g-CSt and NR-g-CSt/MENR blend latex) were also determined usinga micro-electrophoresis apparatus (Zetasizer 4, Malvern) at 25◦C,in a pH 7 medium. A known weight of the graft copolymer filmof specific dimensions (2.5 cm × 2.5 cm × 0.5 mm) was immersedin toluene, benzene oil and water for a period of 5 days at 32◦C.The sample was dried in an oven at 50◦C for 24 h and then weigheduntil a constant weight was achieved. The %swelling was calculatedfrom Eq. (2) as follows: