Polyolefins, functionalization

Phosphites Tris-(p-nonylphenyl) phosphite (X) No Widely used in conjunction with conventional stabilisers (q.v.) in PVC. Some types appear to be useful heat and light stabilisers in polyolefins. Function primarily as peroxide decomposers rather than chain-breaking antioxidants. 

Scheme 12 Polyolefin functionalization by carbene insertion catalyzed by Tp Cu (NCMe)...

MAH is one of the monomers most often used for polyolefins functionalization. It is characterized by an extremely low capacity to homopolymerization, and this fact is explained by the steric features of its structure. The reactivity of MAH to macroradicals, however, is comparatively low. From the chemistry viewpoint, a steric hindrance and a lack of electron density in the double bond explain the low reactivity of MAH, which in MAH is symmetrical owing to the presence of two carbonyl groups. Attempts have repeatedly been made to work out procedures for increasing the chemical activity of MAH. Three methods have been proposed to activate the double bonds in MAH (i) to perform a grafting reaction for MAH in presence of an electron-donating monomer, for example, styrene, which is capable of forming a charge transfer complex (CTC) with MAH (ii) substitution... 

Table 10.5 Dependence of Properties of Initial Polyolefins, Functionalized (PP/LDPE)-g-IA Blends and Unmodified PP/LDPE Blends on the Ratio of Polymer Components.

Surface-initiated anionic polymerization provides an alternative approach to polyolefin-functionalized CNTs that would have potential applications in the reinforcement of widely used polyolefins such as PE and PP. 

Montell Polyolefins, Functional Chemicals, Three Little Falls Centre, 2801 Centerville Road, PO Box 15439, Wilmington, DE 19850-5981, USA Montell Polyolefins, Woluwe Garden, Woluwedal 24, B-1932 Zaventem, Belgium tel +32-2-71 5-8164 fax +32-2-715-8264 Morton International Inc, Morton Plastics Additives, 2000 West Street, Cincinnati, OH 45215-3431, USA tel +1-513-733-2100 fax +1-513-733-213 3 Multibase Inc, 3835 Copley Road, Copley, OH 44321, USA tel +1-216-867-5124 fax +1-216-666-7419... 

Aglietto, M., Alterio, R., Bertani, R., Galleschi, F., and Ruggeri, G. (1989) Polyolefins functionalization by carbene insertion for polymer blends. Polymer, 30, 1133-1136. 

Copolymerization presents a one-step, simple, and convenient way of polyolefin functionalization [34], It implies the use/development of highly versatile catalytic systems able to (co)polymerize a large variety of monomers. In this context, we studied the effect of polymer chain tfansfer in a coordination copolymerization process. 

Amin SB, Marks TJ (2008) Versatile pathways for in-situ polyolefin functionalization with heteroatoms catalytic chain transfer. Angew Chem Int Ed Engl 47(11) 2006-2025. doi 10.1002/anie.200703 310... 

Figure 10.11 Synthetic route to precision polyolefins functionalized with phosphonic acids and sulfonic acid esters.

During recent decades, transition metal complexes have been central in the catalysis of many new and existing organic reactions. Some of these complexes have been successfully adopted for polymer fimctionahzation. In this review article, we summarize the recent progress of polyolefin functionalization catalyzed by transition metal complexes. The sections are con-veniendy divided according to polyolefin structure. We discuss modifications of poly olefins containing (i) alkene C—H bonds such as those in PBD, (ii) aromatic C—H bonds such as those in PS, and (iii) saturated C—C and C—H bonds such as those in PE. A number of excellent review articles and books have extensively discussed the chemical modifications of... 

Blends of PA6 and LDPE were compatibilized by melt mixing with various polyolefins functionalized with glycidyl methacrylate (LDPE-g-GMA, SEBS-g-GMA, E-GMA) [102, 103], acrylic acid (EAA), and maleic anhydride (LDPE-g-MA, SEBS-g-MA) [104,105]. The compatibilized blends showed a neat improvement of phase dispersion and interfacial adhesion when compared to PA6/LDPE binary blends (Fig. 10.23). The... 

Hindered amines, such as 4-(2,2,6,6-tetramethylpiperidinyl) decanedioate, serve as radical scavengers and will protect thin Aims under conditions in which ultraviolet absorbers are ineffective. Metal salts of nickel, such as dibutyldithiocarbamate, are used in polyolefins to quench singlet oxygen or elecbonically excited states of other species in the polymer. Zinc salts function as peroxide decomposers. 

In order for a soHd to bum it must be volatilized, because combustion is almost exclusively a gas-phase phenomenon. In the case of a polymer, this means that decomposition must occur. The decomposition begins in the soHd phase and may continue in the Hquid (melt) and gas phases. Decomposition produces low molecular weight chemical compounds that eventually enter the gas phase. Heat from combustion causes further decomposition and volatilization and, therefore, further combustion. Thus the burning of a soHd is like a chain reaction. For a compound to function as a flame retardant it must intermpt this cycle in some way. There are several mechanistic descriptions by which flame retardants modify flammabiUty. Each flame retardant actually functions by a combination of mechanisms. For example, metal hydroxides such as Al(OH)2 decompose endothermically (thermal quenching) to give water (inert gas dilution). In addition, in cases where up to 60 wt % of Al(OH)2 may be used, such as in polyolefins, the physical dilution effect cannot be ignored. 

Compared with more common plastics used as packaging materials, the compound does have some disadvantages, such as a high water vapour permeability and limited heat resistance, losing dimensional stability at about 70°C. It is also substantially more expensive than the high-tonnage polyolefins. Last but not least its biodegradability means that it must be used in applications that will have completed their function within a few months of the manufacture of the polymer compound. 

A long-standing goal in polyolefins is the synthesis of polymers bearing polar functional groups such as acrylate, esters, or vinyl ethers, etc [24,40]. These copolymers might endow polyolefins with useful properties such as adhesiveness, dyeability, paintability, and print-ibility. Advances have recently been made in polymerizing polar monomers with cationic metallocene catalysts... 

T. C. Chung, New utilities of metallocene catalysts and borane reagents in the functionalization and block/graft reactions of polyolefins, MetCon 95 Proceedings, USA, May 1995. 

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