Polymer synthese

Hydrocarbon resin is a broad term that is usually used to describe a low molecular weight thermoplastic polymer synthesized via the thermal or catalytic polymerization of coal-tar fractions, cracked petroleum distillates, terpenes, or pure olefinic monomers. These resins are used extensively as modifiers in the hot melt and pressure sensitive adhesive industries. They are also used in numerous other appHcations such as sealants, printing inks, paints, plastics, road marking, carpet backing, flooring, and oil field appHcations. They are rarely used alone. 

Despite these early successes in the commercialization of acrylic polymers, no acrylic PSAs were manufactured on a larger scale until many years later. One of the primary reasons for the initial commercial failure of the acrylic PSAs was their lack of cohesive strength. Unlike the higher Tg, plastic-like polymers obtained from monomers like methylmethacrylate, polymers synthesized from alkyl acrylates typically formed sticky, cold-flowing materials with little if any utility. 

The presence of ether linkages in the polymer molecule imparts chain flexibility, lowers glass transition temperature, and enhances solubility while maintaining the desired high temperature characteristics [192]. Recently, polyether imines were prepared by the reaction of different diamines with 4,4 -[l,4-phenylene bis(oxy)] bisbenzaldehyde [184]. The polymers synthesized by the solution method were yellow to white in color and had inherent viscosities up to 0.59 dl/g in concentrated H2SO4. Some of these polyimines can be considered as... 

S. R. Sander and W. Karo, Polymer Syntheses, Organic Chemistry Monographs Vol. 29(1), Academic Press, New York, p. 367 (1974). 

Knowledge of kui/kii is also important in designing polymer syntheses. For example, in the preparation of block copolymers using polymeric or multifunctional initiators (Section 7.6.1), ABA or AB blocks may be formed depending on whether termination involves combination or disproportionation respectively. The relative importance of combination and disproportionation is also important in the analysts of polymerization kinetics and, in particular, in the derivation of rate parameters. 

Transfer agents find widespread use in both industrial and laboratory polymer syntheses. They are used to control ... 

The thiocarbonylthio group can be transformed post-polymerization in a variety of ways to produce end-functional polymers or it can be removed. The presence of the thiocarbonylthio groups also means that the polymers synthesized by RAFT polymerization are usually colored and they possess a labile end group that may decompose to produce sometimes odorous byproducts. Even though the color and other issues may be modified by appropriate selection of the initial RAFT agent, these issues have provided further incentive to develop effective methods for treatment of RAFT-synthesized polymer to transform the thiocarbonylthio groups post-polymerization. 

This book will be of major interest to researchers in industry and in academic institutions as a reference source on the factors which control radical polymerization and as an aid in designing polymer syntheses. It is also intended to serve as a text for graduate students in the broad area of polymer chemistry. The book places an emphasis on reaction mechanisms and the organic chemistry of polymerization. It also ties in developments in polymerization kinetics and physical chemistry of the systems to provide a complete picture of this most important subject. 

PAs can be divided into polymers synthesized from diamines and diacids, called AA-BB-type polymers as in (3.1) and polymers based on amino acids, called AB-type polymers as in (3.2) ... 

Figure 5.21 (a) Monomers and (b) polymers syntheses by Suzuki reaction. 

P. E. Cassidy, Thermally Stable Polymers, Syntheses and Properties, Marcel Dekker, New York, 1980. 

Because side-chain groups can be easily introduced in the polymer backbone, polymers synthesized via transition metal coupling are usually soluble in common... 

Poly(para-phenylenevinylene)s (PPVs) represent one of the most intensively investigated classes of rr-conjugated materials. Many synthetic procedures to generate unsubstituted and substituted PPVs have been developed. They include 1,6-polymerizations of 1,4-xylylene intermediates as well as several polycondensation methods. Parallel to the polymer syntheses, several series of PPV oligomers (OPVs) have been synthesized and characterized. Such model oligomers of different molecular size allow for a study of the dependence of electronic and optical properties on the length of the conjugated Ti-system. 

Ayres L, Vos MRJ, Adams P et al (2003) Elastin-based side-chain polymers synthesized by atrp. Macromolecules 36 5967-5973... 

The phase transition boundaries (phase envelope) of adamantane need to be investigated and constmcted. Predictable and diverse geometries are important features for molecular self-assembly and pharmacophore-based dmg design. Incorporation of higher diamondoids in solid-state systems and polymers should provide high-temperature stability, a property already found in polymers synthesized from lower diamondoids. 

As early as 1952, Flory [5, 6] pointed out that the polycondensation of AB -type monomers will result in soluble highly branched polymers and he calculated the molecular weight distribution (MWD) and its averages using a statistical derivation. Ill-defined branched polycondensates were reported even earlier [7,8]. In 1972, Baker et al. reported the polycondensation of polyhydrox-ymonocarboxylic acids, (OH)nR-COOH, where n is an integer from two to six [ 9]. In 1982, Kricheldorf et al. [ 10] pubhshed the cocondensation of AB and AB2 monomers to form branched polyesters. However, only after Kim and Webster published the synthesis of pure hyperbranched polyarylenes from an AB2 monomer in 1988 [11-13], this class of polymers became a topic of intensive research by many groups. A multitude of hyperbranched polymers synthesized via polycondensation of AB2 monomers have been reported, and many reviews have been published [1,2,14-16]. 

Pyrrolidinopyridine based polymers react faster with benzyl chloride than low molecular weight analogs. The polymer synthesized by cyclopolymerization of N-4-pyridyl bis(methacrylimide)... 

Thermal Analysis - Differential Scanning Calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to characterize the thermal properties of the polymers synthesized. DSC analysis was performed on a Perkin-Elmer Differential Scanning Calorimeter, Model 2C with a thermal analysis data station. Thermal gravimetric analysis (TGA) was carried out on a DuPont thermal gravimeter, Model 951. From the DSC and TGA plots of poly (N-pheny 1-3,4-dimethylene-... 

Figure 6. Novel conjugated heteroaromatic polymers synthesized by redox elimination.

Compounds XIV - XVII have potential for use in subsequent phosphazane ollgomer/polymer syntheses because of their available functionality. In fact, treatment of XVI with two equivalents of Ph2PCl in the presence of Et3N yields the P(III)-P(V)-P(III) triphosphazane XVIII quantitatively. Compounds XV and XVII are especially interesting because they are A-B type 1,4- stabilized reactive monomers (prepolymers) (14). Because A-B monomers contain both elements of functionality necessary for condensation, precise control of the reactant ratio can be maintained and products with the highest possible molecular weights can be expected (14). 

Odian, G. Principles of Polymerization, 3rd Edition. (1991) John Wiley and Sons, Inc. New York. Sandler, R. S. Karo, W. Polymer Syntheses Volume 1, 2nd edition. (1992) Academic Press, Inc, San Diego. 

Iterative procedures hold the potential of automated production as employed reliably and frequently in the case of the Merrifield synthesis. Furthermore, the specific isolation of intermediates and the precise insertion of substituents compensates the enhanced preparative effort compared to polymer syntheses. 

Types of chain polymerisations and polymers synthesized — keypoints of mechanisms, kinetics... 

It has also to be emphasised that polymers synthesized by chain polymerisation can undergo random degradation (as polypropylene for instance), while certain polymers synthesized by step polymerisation can depolymerise (e.g., polyamide 6). 

Figure 23 General structure of a hyperbranched polymer synthesized by the polymerization of AB2 monomer.

By means of genetic engineering, including cloning and site-directed mutagenesis, it has become possible for modern synthetic chemists to utilize a sufficient amount of isolated enzyme catalysts and to modify the reactivity, stability, or even specificity of enzymes. Therefore, polymerizations catalyzed by isolated enzyme are expected to create a new area of precision polymer syntheses. Furthermore, enzymatic polymerizations have great potential as an environmentally friendly synthetic process of polymeric materials. 

Ritter H (1996) Functionalized polymers via enzymatic synthesis. In Arshady R (ed) Desk references of functional polymers syntheses and applications. ACS, Washington,... 

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