Phenolic-styrene polymers

The thermoplastic or thermoset nature of the resin in the colorant—resin matrix is also important. For thermoplastics, the polymerisation reaction is completed, the materials are processed at or close to their melting points, and scrap may be reground and remolded, eg, polyethylene, propjiene, poly(vinyl chloride), acetal resins (qv), acryhcs, ABS, nylons, ceUulosics, and polystyrene (see Olefin polymers Vinyl polymers Acrylic ester polymers Polyamides Cellulose ESTERS Styrene polymers). In the case of thermoset resins, the chemical reaction is only partially complete when the colorants are added and is concluded when the resin is molded. The result is a nonmeltable cross-linked resin that caimot be reworked, eg, epoxy resins (qv), urea—formaldehyde, melamine—formaldehyde, phenoHcs, and thermoset polyesters (qv) (see Amino resins and plastics Phenolic resins). 

The tonnage of plasticisers consumed each year exceeds the annual tonnage consumption of most plastics materials. Only PVC, the polyolefins, the styrene polymers, the aminoplastics and, possibly, the phenolics are used in large quantity. 

Benzene is an important chemical intermediate and is the precursor for many commercial chemicals and polymers such as phenol, styrene for poly-... 

Fig. 7. Bromination of phenols with styrene polymer-bound BTMA Br3...

Non-discoloring, sulfur containing phenolic antioxidant and stabilizer that provides long-term heat stability by preventing thermo-oxidative degradation. Used for the process stabilization of polyethylene wire and cable resins for polyethylene during extruder compounding. Can also be applied in styrenic polymers, polypropylene, elastomers such as EPDM and SBR and for carboxylated SBR latex, polybutadiene rubber and polyisopropene rubber. 

Mixtures of rubber latices or elastomer foams were modified with colloidal silica to give improved properties. Typical processes involved drying, gelling, or coagulating the colloidal silica within the elastomer system. Silica sols were used with phenolic, formaldehyde-based, melamine, polyester, acrylic, vinyl or styrene polymer-copolymer, polyamide, and styrene-butadiene rubber systems to provide strength to films and coatings. 

Degradation in the presence of solvents has also been applied to the conversion of other styrenic polymers, such as poly(p-methylstyrene) and poly(styrene-allyl alcohol).64,65 Figure 4.11 shows the temperature dependence of the conversion of poly(p-methylstyrene) when using phenol, 1-methyl-naphthalene and tetralin as solvents. In this case, tetralin leads to the greatest degradation below 370 °C, whereas the order is reversed above that temperature. These results indicate that the effect of the solvent in the degradation of styrenic polymers is strongly influenced by the temperature. 

Antioxidants. Certain components of heat stabilizers (polyols, phosphites) also serve as antioxidants. The protection against oxidative attack is not as great in PVC as it is in certain ethylenically unsaturated materials. However, PVC compounds may require protection in the high-temperature service as in electrical wire insulation bisphenol A is often incorporated into the plasticizer for this purpose. Impact modifiers containing unsaturation such as acrylonitrile-butadiene-styrene polymers often require antioxidant protection. Hindered phenols such as butylated hydroxytoluene are often used for this purpose, especially when outdoor applications are involved. 

Kuo, S. W., and Chang, R C. 2001. Effect of copolymer composition on the miscibility of poly(styrene-co-acetoxystyrene) with phenolic resin. Polymer 42 9843-9848. 

Prinos, A., Dompros, A., and Panayiotou, C. 1998. Thermoanalytical and spectroscopic study of poly(vinyl pyrrolidone)/poly(styrene-co-vinyl phenol) blends. Polymer 39 3011-3016. 

Naftonox BHT. SeeBHT Naftonox PS. See Phenol, styrenated Naftonox TMQ. See 2,2,4-TrimethyM, 2-dihydroquinoline polymer Naftopas Antimontrioxid, Naftopast Antimontrioxid-CP. See Antimony trioxide Naftopast Di7-P. See Zinc diethyidithiocarbamate Naftopast DH3-P. See Zinc dibutyidithiocarbamate... 

Phenol, styrenated antioxidant, ABS polymers Octyl diphenyl phosphite antioxidant, acetal resins N-(p-Ethoxycarbonylphenyl)-N -ethyl-N-phenylformamidine antioxidant, acrylic coatings Octadecyl 3,5-di-t-butyl-4-hydroxyhydrocinnamate antioxidant, acrylic food packaging Hydroquinone monomethyl ether Octadecyl 3,5-di-t-butyl-4-hydroxyhydrocinnamate Resorcinol benzoate antioxidant, acrylics Drometrizole Triisooctyl phosphite antioxidant, acrylics, ABS 2,2 -Methylenebis (4-ethyl-6-t-butylphenol) antioxidant, acrylonitrile Distearyl thiodipropionate antioxidant, adhesives... 

Styrenic Polymers Stabilization of polystyrene and its copolymers is necessary for articles expected to be exposed to solar radiation or indoor fluorescent lighting. Because of the signiflcant role played by thermal oxidation products in the effect of these sources on the polymers, thermal stabilization at the processing stage is required to reduce their sensitivity to light. The use of a phenolic antioxidant was shown to increase the retention of mechanical properties and. 

The major flame-retarded polymers in the electrical industries are polyamides, polyesters (used in electrical connectors), the epoxy and phenolic thermosetting polymers (used in PCBs), and various types of styrenics for consiuner electronics and business machine housings. 

Deprotection of the t-Boc groups is achieved by reaction with an acid, HX (Scheme 13.6). The acid is generated from photochemical decomposition of iod-onium (R2r X ) or sulfonium (R3S X ) [17]. Deprotection of the t-Boc groups results in the formation of a styrene polymer with soluble phenolic side-chain groups. Thus the photoinduced creation of a soluble polymer from an insoluble one constitutes a positive chemically amplified photoresist. 

Scheme 13.6 Deprotection of Boc-styrene polymer to yield soluble phenol groups...

Naugard P is a cost effective secondary liquid phosphite antioxidant that functions as a peroxide decprocessing stabilizer. When used in conjunction with hindered phenolic and thlodipropionate antioxidants, a synergism is seen. In addition to improved antioxidant activity of these combinations, Naugard P also inhibits discoloration of the polymer caused by some phenolic antioxidants. Polymer applications include polyolefins, styrenics and a variety of other polymers. 

Heitz synthesized polymers with two phenolic end groups by carrying out the polymerization in the presence of a biphenol. Block polyether-polycarbonate and polyether-polyester carbonates were synthesized from these blocks. Percec also prepared a bifunctional PPO by polymerization of 2,6-dimethylphenol in the presence of 2,2 -di(4-hydroxyphenyl-3, 5-dimethylpropane). Etherification of the blocks with chloromethylstyrene gave reactive oligomers that were cross-linkable. When monofunctional PPO was reacted with chloromethyl styrene the resulting styryl-substituted polymers formed comb-like structures on polymerization and could be copolymerized with vinyl monomers. Alternatively, Meijer was able to coredistribute phenol-terminated polymers with PPO to produce block copolymers. ... 

Sulfonated styrene—divinylbensene cross-linked polymers have been appHed in many of the previously mentioned reactions and also in the acylation of thiophene with acetic anhydride and acetyl chloride (209). Resins of this type (Dowex 50, Amherljte IR-112, and Permutit Q) are particularly effective catalysts in the alkylation of phenols with olefins (such as propylene, isobutylene, diisobutylene), alkyl haUdes, and alcohols (210) (see Ion exchange). Superacids. 

---