REACTIVE FILLER

Solutions of the two recipes were blended in varying proportions to provide tie coats of continuously varying composition. The patent shows an example of eight plies or layers of graded composition between the rubber and the metal substrate. Because of the high fraction of reactive filler, the material closest to the metal substrate would be the most rigid and polar. The stiffness and polarity... 

By far the most important phenolic resins are those made from phenol and formaldehyde. They exhibit high hardness, good electrical and mechanical properties, and chemical stability. Very often they are used in combination with (reactive) fillers like sawdust, chalk, pigments etc. 

Zinc oxide is a reactive filler commonly used in rubber vulcanization. The crosslink density of rubber can be doubled by reaction of ZnO with HCl. Only a few specific fillers have the catalytic activity to promote crosslinking but fillers can take part directly in crosslinking processes initiated by an external source such as y-radialion. Generally, fillers reduce the effect of radiation. But y-rays are not screened by the filler so the protection given by fillers comes from reduction in chain mobility which lessens the probability of photoconversion. 

U.S. Pat. No. 7,041,716 [74] describes a thermoplastic composite comprising a polyolefin such as polyethylene or polypropylene in an amount of 20-90% by weight, a cellulose filler such as wood flour in an amount of 30-80% by weight, a basic reactive filler such as glass fibers in an amount of 5-25% by weight, and a carboxylic acid anhydride graft polyolefin such as maleic anhydride grafted polypropylene in an amount of 1-5%. 

Elemental sulfur is altered by chemical, allotropic, or me-chanical means. Of the chemical modifiers the Thiokol family of additives are some of the most effective modifiers available. By control of the time-temperature history of sulfur in the liquid and solid phases, it is possible to control the allotropic modification of sulfur and its mechanical properties. Mechanical modification of sulfur with non-chemically reactive filler materials such as aggregates and fibers yields materials with properties different from those of the parent materials. 

Calcium oxide Reactive filler able to react with CaCl ... 

Wood is not abrasive to equipment like inorganic fillers/fibers, but certain desired properties can only be obtained with additions of mineral fillers such as talc (for lubricity and strength), calcium carbonate, calcium oxide, alumina, wollastonite (for scratch and wear resistance), or even Portland cement, as a reactive filler supplying strength and fire retardancy. 

Densely packed cementitious materials are commonly also called also DSP materials, which is an acronym for Densified Systems containing homogeneously arranged ultrafine Particles. The alternative term reactive powder concrete is also used. In principle these are cementitious materials formed by the Itydration of densely packed particles of an inoiganic binder in combination with ultrafine particles of a second, less reactive or non-reactive filler. Some additional particulate materials may also be present. 

The primary role of MgO in unsaturated polyesters is as a reactive filler/thickening agent in SMC/BMC manufacturing. Incorporation of up to 5% MgO in the formulation allows the production of a tack-free sheet within a few days at room temperature. The sheets can then be easily handled prior to the high-temperature molding step. The increased viscosity assists dispersion uniformity and improves the flow characteristics of the compound prior to the onset of the cross-linking reaction. 

Keywords functional precursors miniemulsion nanopaiticles polymer composites reactive fillers... 

A following step was the copolymerization, using a second monomer, which enables the introduction of a secondary functionality into the emulsion bead. This leads to reactive fillers, which can be varied in composition and concentration of accessible functional groups at the particle... 

With this versatile reaction method we established an easy preparation scheme for reactive fillers with a broad variety of funetionahties in adjustable concentration on the particle surface. 

The presented three step method of inorganic particle preparation, consequent functionalization and finally embedding into a miniemulsion copolymerization system offers an easy way to prepare core shell particles with a wide range of functionalities at the surface. Those products inherit a high potential as reactive filler materials in advanced polymers composites. 

Intrinsically fillers can be divided into two types, reactive and inert. Reactive fillers will react with their environment. A good example of this is gibbsite (aluminium hydroxide), which will react with both acidic and basic substances. Aluminium hydroxide also loses its water of crystallisation at around 200 °C and this enables it to provide fire retardancy in polymer formulations. The silicate minerals (kaolin, mica, talc, quartz, etc.), are, in classical chemical terms, virtually inert, only being attacked by very strong acids and alkalis. The carbonate minerals and the hydroxide minerals are very reactive to acids. 

Chemical attack may also be caused by some reactive fillers, leading to etching and progressive erosion. 

M-Cure 204 also functions as a "reactive filler" in conventional epoxy coatings to increase adhesion to a variety of substrates. 

Single reactive fillers of a typical intumescent system comprising pentaerythritol, melamine, and ammonium polyphosphate, as well as mixtures of these active components, were studied by DSC. The tests on binary and ternary mixtures were performed in weight ratios of 1 1 and 1 1 2,... 

The plastic endblocks phase regions, called domains , are shown in sphere-like form. Other forms are discussed later. These domains act as crosslinks between the ends of the rubber chains, serving to lock the rubber chains and their inherent entanglements in place. The system acts like a conventionally vulcanized rubber that contains dispersed reactive filler particles. 

SBS and SIS Thermoplastic Rubbers (Harlan, 1977 Chu, 1986) - Styrene-butadiene s rene and styrene-isoprene-s rene are thermoplastic rubber block copolymers. They were larst marketed commercially in 1965. The polymers have rubbery midblocks of butadiene or isoprene molecules and two plastic end blocks of styrene molecules. The polymers have the modulus and resilience of vulcanized butadiene and isoprene at room temperature and act as thermoplastics at higher temperatures. When SBS or SIS molecules are combined in the solid phase, a two-phase structure is formed by the clustering of the styrene endblocks. The plastic endblock regions are called domains which act as crosslinks between the ends of the rubber chains (butadiene or isoprene) locking them in place. The block copolymers act like a typical vulcanized rubber that is filled with dispersed reactive filler particles. 

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