Filler treatment

In addition to the considerations based on morphology that have been analyzed above, further strategies for improving mechanical properties are similar to those employed in binary systems, and include filler treatment, addition of compatibilizers, and functionalization of the polymers. These are briefly reviewed below. 

In the case of segregated and encapsulated morphologies, it is important to note that since the fillers reside preferentially in one of the two phases, the actual filler loading contained in that particular phase is increased. For example, in a 70/30 polymer blend assuming that 5 wt% of a filler is introduced and resides in the dispersed phase, its actual concentration in the dispersed phase would be 15 wt%. The increase in filler loading inevitably results in filler aggregation, which can be very detrimental. The issue of filler treatment becomes therefore even more important in these systems. 

---

Table 2. Composition of some typical fatty acid blends of the type used for filler treatment...

In the following section, a new technique of surface modification of fillers and curing agents will be discussed plasma polymerization. This technique allows for surface coating of powders, whereby the chemical structure of the coating is determined by the monomer used for the process. The morphology of the substrate is preserved, which is an important precondition for filler treatment. The polarity of the functional groups can be chosen to fit the matrix of the polymer wherein it will be applied. 

Nevertheless, with regard to filler treatment and limestone impregnation, it is still considered difficult to coat calcium carbonate with silicone. As shown in Table 1, the commercial monomeric silanes that are used for coating the surfaces of fillers nowadays are not effective for coating calcite [19, 20, 21]. The idea that the production of a silicone-coated surface is difficult may result from the misconception that attachment of high silicone polymers to calcium carbonate is equally problematic. The issue of attachment of silicone to the mineral surfaces has still not been finally resolved [62]. 

The specific surface area depends on filler treatment. The treatment of carbon based materials is one of such examples (Figure 5.12). Surface oxidation increases the specific surface area of carbon fibers. 

It is difficult to conclude from the data in Table 10.1 whether the filler addition increases or decreases crystallinity. The lack of a clear pattern in the results is caused by differences in filler treatment and processing which cause the development of different structures as the material crystallizes. These points will be further discussed in the next paragraphs. 

Chem. Descrip. Methyl trimethoxy silane CAS 1185-55-3 EINECS/ELINCS 214-685-0 Uses Pigment and filler treatment in solv. and water-based systems primer reduces pigment separation and floating improves disp. adhesion promoter... 

Chem. Descrip. Phenyl trimethoxy silane CAS 2996-92-1 EINECS/ELINCS 221-066-9 Uses Surf, treatment, pigment/filler treatment in primers, water repellents, paints, inks, and adhesives reactive intermediate tor silicone resin synthesis and org. resin modification adhesion promoter Properties Low-vise, liq. sp.gr. 1.05 vise. 1.7 cSt flash pt. (CC) 29 C 100% act. 

Uses Reactive intermediate in the synthesis of silicone-organic copolymers for protective coatings provides a water repellent protective coating for wood, masonry, and metal substrates also for mold release agents, filler treatments (hydrophobic surf.)... 

CAS 58160-99-9 EINECS/ELINCS 261-145-5 Uses Adhesion promoter for water-sol./water-disp. resins incl. vinyl and acrylic latexes, epoxies, and phenolic binder dispersions for sealants, adhesives, coatings, insulation binders finish forwoven fiberglass filler treatments coupling agent for glass fiber sizes Properties Lt. straw clear liq. sol. in water insol. in toluene, ethyl ether, CCL reacts with acetone sp.gr. 1.076 vise. 4 cSt flash pt. (PMCC) > 66 C... 

Chem. Descrip. Bis-(3-[triethoxisily0 propyl)-tetrasulfane CAS 40372-72-3 EINECS/ELINCS 254-896-5 Uses Coupling agent for polysulfide and styrene-butadiene polymers, butyl polymers, for adhesives, coatings, filler treatment, foundry, inks, rubber, sealants, and textile applies. 

Uses Crosslinker, adhesion promoterfor RTV silicone sealants improves adhesion to PVC and other substrates crosslinker in polymer modification coupling agent for adhesives, coatings, inks, sealants, rubber filler treatment in thermoset/thermoplastic resins fiberglass textiles foundry crude oil extraction ManufJDistrib. ABCR Aldrich Gelest Trade Names Silquest Y-11597... 

GP-179 Silicone Resin GP-596 SWcone Resin Sol n. GP-667 Silicone Resh Sol n. GP-740 Silicone Resin Sol n. Silquest A-1106 Silquest A-2120 filler treatmerfl, paints Dow Coming Z-6124 Silane filler treatment, primets Dow Coming Z-6124 Silane filler treatment, water repellents Dow Coming Z-6124 Silane filler, ABS... 

Ariffin, A., Mansor, A.S., Ariff, Z. M., Jikan, S.S., Ishak, Z.A.M. (2008). Effect of filler treatments on rheological behaviour of calcium carbonate and talc-filled polypropylene hybrid composites /. Appl. Polym. Sci, 108, 3901-3916... 

---