Polybutylene terephthalate polymerization

In addition to the desired polymerization reaction, the dialcohol reactants can participate in deleterious side reactions. Ethylene glycol, used in the manufacture of polyethylene terephthalate, can react with itself to form a dialcohol ether and water as shown in Fig. 24.4a). This dialcohol ether can incorporate into the growing polymer chain because it contains terminal alcohol units. Unfortunately, this incorporation lowers the crystallinity of the polyester on cooling which alters the polymer s physical properties. 1,4 butanediol, the dialcohol used to manufacture polybutylene terephthalate, can form tetrahydrofuran and water as shown in Fig. 24.4b). Both the tetrahydrofuran and water can be easily removed from the melt but this reaction reduces the efficiency of the process since reactants are lost. 

Apart from ZHS and ZS, little work has generally been undertaken on tin-based Are retardants in nonhalogen polymer systems. However, certain tin(II) compounds have shown excellent flame-retardant and smoke-suppressant properties when incorporated at levels of 20-30% into aromatic polyesters, specifically polybutylene terephthalate (PBT). Hence, tin(ll) oxide, tin(II) oxalate, and tin(II) phosphate have been shown to markedly increase flame retardancy in PBT, whereas, interestingly, tin(IV) oxide is almost totally ineffective in the same polymeric substrate. 

Polybutylene Terephthalate (PBT). With the expiration of the original PET patents, manufacturers pursued the polymerization of other polyalkene teiephthalates, particularly polybutylene terephthalate (PBT). The polymer is synthesized by reacting terephthalic acid with butane 1,4-diol to yield the structure shown in Fig. 2.16. 

FIGURE 9.7 Linear PBT molecule polymerized by reacting butanediol with terephthalic acid. Conventional commercial production of polybutylene terephthalate (PBT) involves a condensation reaction between dimethyl terephthalate and 1,4-butane diol. 

Terephthalate polyester ter- o(f)- tha lat, pa-le- es-tor n. Any polymeric ester of ter-ephthalic acid (1,4-benzene dicarboxylic acid), but in particular the three commercially important thermoplastic resins, polyethylene terephthalate, polybutylene terephthalate, and poly-cyclohexylene dimethylene terephthalate. 

The microwave susceptors in this initial study have been carbon black, magnetite, lead zirconate titanate, and silicon carbide. The polymeric matrix for these trials has been mainly high density polyethylene, which is a nonpolar polymer without any absorption of microwave radiation. Other thermoplastic matrixes like polyamide 6 (PA6), polybutylene terephthalate (PBT) and metallocene polypropylene (m-PP) have been used as reference material. 

El Fray and Altstadt [12] used MTA to study the relationship between morphological features of semi-crystalline and multi-block polymeric materials and their thermal properties. Samples of semi-crystalline polybutylene terephthalate and its copolymer were crystallised from the melt showing a spherulitic morphology. The surface of the spherulitic shapes was subjected to L-TA at selected regions of different thermal conductivity (at the centre of the spherulite and at its outer surface). This reveals information, which cannot otherwise be obtained. 

The promise of large-scale low-cost fermentations from renewable resources, especially corn, has spurred interest in the United States to develop chemical production for large-volume chemicals using bio-based processes. Succinic acid can be converted by hydrogenation to 1,4-butanediol, which has a world market in excess of 500,000 metric tons. Butanediol is used to produce polybutylene terephthalate (PBT) resins that have desirable mechanical and thermal properties and are a high-performance version of polyethylene terephthalate resins (PET). Also, 1,4-butanediol is a precursor of tetrahydrofuran, which can be polymerized to polytetrahydrofuran (PTHF). Gamma butyrolactone (GBL) can also be derived from 1,4-butanediol, and much of GBL is used to manufacture the solvent N-methyl-2-pyrrolidone (Szmant 1989). 

The majority of fiber-forming polymers, like common plastics, are based on petrochemical sources. Polymeric fibers can be produced from the following materials polyamide nylon, polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) polyesters, phenol-formaldehyde (PF), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and polyolefins (polypropylene (PP) and polyethylene (PE)) among others. Because of the different chemical structures of fiber-forming polymers, their applications vary widely according to the temperature and chemical conditions which they can withstand. For example, polyethylene melts into a viscous liquid at temperatures equal to or less than that of a domestic dryer and therefore its application in a product that will require normal laundering is not possible. However, its fibers can be used in making disposable non-woven products. ... 

The chemical pretreatment methods mentioned are mostly used for TPOs, but in some cases can also be effective when used on polyamide (PA), polybutylene terephthalate (PBT), or other crystalline polymers, as well as some blends like poly(phenylene oxide)/polyamide (PPO/PA), are flamed. As a possible future trend, research is currently underway (plasma polymerization) attempting to combine a pretreatment for adhesion and to provide the surface conductivity on necessary on plastic parts for acceptable electrostatic application (15). 

Polyethylene terephthalate [25038-59-9] (8) is a polyester produced by the condensation polymerization of dimethyl terephthalate and ethylene glycol. Polyethylene terephthalate sutures are available white (undyed), or dyed green with D C Green No. 6, or blue with D C Blue No. 6. These may be coated with polybutylene adipate (polybutilate), polyydimethylsiloxane, or polytetrafiuoroethylene [9002-84-0]. The sutures are distributed under the trade names Ethibond Exel, Mersdene, Polydek, Silky II Polydek, Surgidac, Tevdek II, Polyester, and Tl.Cron. 

MC MDI MEKP MF MMA MPEG MPF NBR NDI NR OPET OPP OSA PA PAEK PAI PAN PB PBAN PBI PBN PBS PBT PC PCD PCT PCTFE PE PEC PEG PEI PEK PEN PES PET PF PFA PI PIBI PMDI PMMA PMP PO PP PPA PPC PPO PPS PPSU Methyl cellulose Methylene diphenylene diisocyanate Methyl ethyl ketone peroxide Melamine formaldehyde Methyl methacrylate Polyethylene glycol monomethyl ether Melamine-phenol-formaldehyde Nitrile butyl rubber Naphthalene diisocyanate Natural rubber Oriented polyethylene terephthalate Oriented polypropylene Olefin-modified styrene-acrylonitrile Polyamide Poly(aryl ether-ketone) Poly(amide-imide) Polyacrylonitrile Polybutylene Poly(butadiene-acrylonitrile) Polybenzimidazole Polybutylene naphthalate Poly(butadiene-styrene) Poly(butylene terephthalate) Polycarbonate Polycarbodiimide Poly(cyclohexylene-dimethylene terephthalate) Polychlorotrifluoroethylene Polyethylene Chlorinated polyethylene Poly(ethylene glycol) Poly(ether-imide) Poly(ether-ketone) Polyethylene naphthalate Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde copolymer Perfluoroalkoxy resin Polyimide Poly(isobutylene), Butyl rubber Polymeric methylene diphenylene diisocyanate Poly(methyl methacrylate) Poly(methylpentene) Polyolefins Polypropylene Polyphthalamide Chlorinated polypropylene Poly(phenylene oxide) Poly(phenylene sulfide) Poly(phenylene sulfone)... 

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