ATRP Grafting from Cellulose Fibers to Create Block-Copolymer Grafts

Abstract

Cellulose fibers, in the form of a conventional filter paper, have been modified by reacting the hydroxyl groups on the fiber surface with 2-bromoisobutyryl bromide, followed by grafting using ATRP conditions. The papers were first grafted with methyl acrylate (MA), rendering the paper very hydrophobic as reported in an earlier work. The papers were analyzed by gravimetry, FT-IR, ESCA, and AFM. To verify that the polymerization from the surface was "living", a second layer of another, hydrophilic, polymer, 2-hydroxyethyl methacrylate (HEMA), was grafted upon the PMA layer, creating a block-copolymer graft from the fibers. After the layer of PHEMA had been attached, contact angle measurements were no longer possible, because of the absorbing nature of PHEMA-grafted layer. This indicates that a copolymer had indeed been formed on the surface. FT-IR showed a large increase in carbonyl content after the PHEMA-grafting, which further proves that a layer of PHEMA was attached to the PMA layer. This goes to show that the hydrophilic/hydrophobic behavior of a cellulose surface can be tailored by the use of "living"/controlled radical polymerization methods such as ATRP.

The preparation of graft copolymers of cellulose and cellulose derivatives using ATRP under homogeneous reaction conditions

“…This has received much less attention than the alternative approach of grafting onto the surface of solid cellulosic materials (selected 6" " relevant references are cited here 37,38,39 ). The review is arranged into sections based on the parent cellulose derivative undergoing chemical modification.…”

Addition of mechanically processed cellulosic fibers to ionomer cement: mechanical properties

“…10,11,12 Cellulosic fibers meet this need because they possess desirable intrinsic characteristics, such as low cost and density, specific resistance and high elastic modulus, and resistance to compression (or flattening); they are also rigid, non-abrasive, and non-toxic; are easily modified by chemical agents; and are entirely renewable, being the most abundant organic compound on the planet. 2,5,13,14 Considering the positive properties of cellulosic fibers and their potential to improve the mechanical properties of materials used in dentistry, here, we incorporate mechanically processed cellulose fibers into conventional restorative glass ionomer cement (GIC). We evaluate the parameters of the modified GIC, namely, the compressive strength, elastic modulus, and diametral tensile strength and stiffness, and characterize the materials by scanning electron microscopy and energy dispersive X-ray spectroscopy.…”

Surface Grafting of Paper with Photochromic Spiropyran Ether Methacrylate

“…The crystallinity index of fiber, fiber initiator, and fiber-g-PSPMA were 67.55%, 62.41%, and 61.83%, respectively. This indicated that the graft reaction occurred only at the surface of the fiber, and the structure of filter paper was not damaged during the reaction (Carlmark and Malmström 2003). …”

“…Hence, polymerization reaction carried out both from the surface of fibers and the reaction system, which were triggered from fiber initiator and the sacrificial initiator. This method also used to assess the polymer grafted on the fiber surface (Carlmark and Malmström 2003). The grafted PSPMA were analyzed by GPC and the main result is listed in Table 2.…”