Stabilizer masterbatch

Bulk grafting of polyolefins with functionalized monomers can be performed by means of conventional processing equipment. Inherently stabilized polyolefins are formed when low concentrations of functionalized monomers are used [218]. Using high concentration levels of the latter, stabilizer masterbatch for blending with undoped polyolefins are created. -Functionalized polyolefins can be prepared by means of the radical grafting more successfully than via copolymerization. 

Photostabilization processes have not received much attention in the last year other than a multitude of review and specialist industrial articles. These include stabilization of polypropylene fibres, new stabilizer developments, sorting of stabilizers for polyethylene, trends in UV absorbers, " hindered piperidines (HALS) for polyacryUcs and urethanes, new stabilizers for polyolefins, enhanced service-life applications, stabilizer masterbatches for polyester, stabilizers for UV-cured acrylic overcoats for PVC and stabilization of clearcoats and various commercial packages. ... 

A range of high-performance UV stabilizer masterbatches for polyesters has been introduced by Chemiehandel SE, Switzerland, under the Sukano name. They are... 

Red Phosphorus. This aHotropic form of phosphoms is relatively nontoxic and, unlike white phosphoms, is not spontaneously flammable. Red phosphoms is, however, easily ignited. It is a polymeric form of phosphoms having thermal stabiUty up to ca 450°C. In finely divided form it has been found to be a powerful flame-retardant additive (26,45—47). In Europe, it has found commercial use ia molded nylon electrical parts ia a coated and stabilized form. Handling hazards and color have deterred broad usage. The development of a series of masterbatches by Albright Wilson should facihtate further use. 

Due to the high level of binding of stabilizing moieties in unsaturated rubbers or EPDM, masterbatches can be formed by this way and used for the stabilization... 

Oligomeric and polymeric stabilizers which have high physical persistence can be used as masterbatches and blended with unstabilized polymers using conventional techniques [243]. The concentration level of polymeric additives should be kept to limits ensuring a sufficient molar concentration of stabilizing moieties, i.e. an efficient protection of the host polymer. 

Special considerations chemical composition of filler surface affects nucleation of filler traces of heavy metals decrease thermal stability and cause discoloration siuface free energy of fillers determines interaction large difference in thermal properties of fillers and polymer may cause stress hydrotalcite is used as acid neutralizer with stabilizing packages anatase titanium dioxide decreases UV stability presence of transition metals (Ni, Zn, Fe, Co) affects thermal and UV stability calcium carbonate and talc were found to immobilize HALS stabilizers in PP with organic masterbatches such as ethylene diamine phosphate V-0 classification can be obtained with 20-25 wt%, at the same time tensile strength and impact strength are substantially reduced... 

Numerous articles of a general interest have appeared on photocatalytic chemistry. These include nanoparticles, protection of buildings, antibacterial properties, ageing of pigment blends, modified titanium dioxides, photocatalytic paints, stabilization of pigmented systems, sensitization of acid dyes " and clay masterbatches. Anatase has been found to have a detri-... 

Tests of the light stabilizing activity of monomeric HAS and the corresponding homo- and copolymers reveal mostly better properties of the monomers if physical persistence is not the decisive testing factor [8]. This was found e.g. in comparison of the functionalized urethane 182 and its copolymers with styrene or methyl methacrylate [303], The macromolecular architecture is expressed very distinctly. For example, a PP photografted HAS-functionalized acrylate was more efficient than the respective monomer or homopolymer. Another observation performed with A-(2,2,6,6-tetramethyl-4-piperidyl)methacry-lamide, piperidyl acrylate and methacrylate, their homopolymers and copolymers with dodecyl methacrylate and octadecyl acrylate revealed that the stabilizing effect in PP was in favour of copolymers [304]. Similar HAS-functionalized monomers were copolymerized with styrene. In this case, the copolymers were substantially less efficient in PS than the monomers. Masterbatches of PP-bound HAS prepared by reactive processing imparted a comparable effectivity as conventional HAS when tested at an equimolar basis [298]. 

Stabih [Henkel KGaA] Stabilizer/lu-bricant masterbatches. 

For stabilization of polyolefins in contact with copper, it is often mandatory to combine a metal deactivator with an antioxidant. Metal deactivators in actual use are essentially N,N -bis-[3-(3, 5 -di-te t-butyl-4 -hydroxy-phenyl)propionyl]-hydrazine and NJV -dibenzaloxalyldihydrazide. The latter compound requires predispersion in a masterbatch because of its insolubility in polyolefins. This is not needed, however, for the former compound, which at commonly used concentrations is molecularly dispersed in polyolefins after processing. The required additive concentrations range from 0.05 to 0.5% depending on the polymer, the nature of the insulation (solid, cellular), whether the cable is petrolatum filled, and on service conditions. 

Masterbatches, concenttates, and the NDB example also address worker health and safety, a major concern when handling polymer additives. In their raw forms, for example some light stabilizers and antadds can be skin irritants, while fine particulates from common additives can create respiratory problems or the risk of explosion. Using non-combustible, non-dusting versions of these additives is just one approach, along with adequate ventilation, fume-exttaction, dust-collection, static-dissipation, and other common factory protections,... 

Chem. Descrip. Rutile titanium dioxide, stabilized with Al Uses Pigment for plastics (PS and copolymers, polyolefins, plasticized PVC), elastomers, linoleum, masterbatches, food-contact coatings/pa-per... 

PE-g-MAH/MMT masterbatch-based nanocomposites. These trends for the EVA-based nanocomposites further attest to the effectiveness of the PO-g -MAH in stabilizing OLS filler networks. 

Hyperdispersants are low-molecular-weight block copolymers designed to separate filler and pigment particles from each other, disperse them more readily in hquid systems, and stabilize these dispersions for more efficient use of the sohd particles. One block is designed to be attracted to the surface of the solid particle, the other block to be attracted into the plasticizer, polyolefin, or other matrix being used for the masterbatch, and also into the final matrix polymer in the finished product. The exact nature of these block copolymers is still a secret of their developers and producers. 

In terms of functions, the emphasis is now on improvement of film processing, anti-static additives, special effect pigments, multi-functional fillers, and stabilizing systems for engineering plastics. Many of the new developments in individual additives are now being offered at the same time in safe, convenient technical masterbatch formulations. 

Partial substitution of Ti02 pigments with double the quantity of ZnS does not impair brightness, pigment dispersion, or melt flow index of a masterbatch, but reduces friction and abrasion and increases temperature stability. It can thus act as a processing aid, especially in linear LDPE. 

Table 9.3 Typical UV stabilizing systems in masterbatch form"...

The new additive masterbatches are products that are free of nickel quenchers, improving the stability of polyethylene films and developed specifically for horticultural films likely fo be contaminated by pesticides. They will provide protection for up to four years, even in high-radiation areas such as the Mediterranean. 

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