Long-chain alkyl groups, vinyl

Mechanical Properties of DAP Resins Cocured Microheterogeneously with Vinyl Monomers Having Long-Chain Alkyl Groups... 

DAP was cocured in bulk with vinyl monomers having long-chain alkyl groups, including vinyl laurate (VL), dioctyl fumarate (DOF), lauryl methacrylate (LMA), and stearyl methacrlate (SMA) (12). 

This type of microheterogeneous copolymerization of DAP with vinyl monomers having long-chain alkyl groups was applied further for the bulk copolymerization systems to obtain direct evidence to support the idea of the microheterogeneity of the systems beyond the gel-point conversion [82]. Also, the solution copolymerization of DAT was explored to demonstrate the incompatibility of the initially obtained precopolymer with a high content of comonomer units with DAT-enriched polymer chains [83]. 

Methods of Preparation of Hydrophobically Modified WSPs (HMWSPs). Incorporation of Hydrophobes into WSPs. Water-soluble cellulose derivatives ((hydroxyethyl)cellulose, (hydroxypropyl)cellulose, methylcellulose, etc.) or synthetic polymers containing hydroxyl groups (e.g., poly(vinyl alcohol)) can be reacted with a long-chain alkyl halide (2), acyl halide (2), acid anhydride (6), isocyanate (2), or epoxide (2, 3) under appropriate conditions to form an HMWSP. These reactions are shown in Scheme I. These postmodifications can be done in solution or in hetero-... 

It is difficult to control the stereoregularity of polymers in radical telomerization. However, the side chain ordering in the polymer can be realized if a long-chain alkyl compound is chosen as a vinyl monomer for telomerization. A preliminary example is reported with poly(octadecyl acrylate), ODA . The resultant polymer can be easily grafted onto porous silica through a terminal trimethoxy-silyl group. Toluene and tetrachloromethane are good solvents for this procedure. 

Esters of vinyl alcohol can be transformed with high bll ratios and enantiomeric excess values into corresponding a-formyl esters by using Rh[(R,S)-BINAPHOS] (Scheme 4.66) [36]. The nature of the acyl group had almost no effect on the results. The outcome of the reaction was also rather independent of temperature differences between 60 and 80 °C. Only with long-chain alkyl esters (n-heptyl) at temperature lower than 60 °C and S/C ratios of >1000 1, the rate of conversion and the enantiomeric excess values, respectively, eroded. Partial racemization of the product can be probably avoided by transformation into the corresponding... 

In addition polymerization, monomers react to form a polymer chain without net loss of atoms. The most common type of addition polymerization involves the free-radical chain reaction of molecules that have C = C bonds. As in the chain reactions considered in Section 18.4, the overall process consists of three steps initiation, propagation (repeated many times to build up a long chain), and termination. As an example, consider the polymerization of vinyl chloride (chloro-ethene, CH2 = CHC1) to polyvinyl chloride (Fig. 23.1). This process can be initiated by a small concentration of molecules that have bonds weak enough to be broken by the action of light or heat, giving radicals. An example of such an initiator is a peroxide, which can be represented as R—O—O—R, where R and R represent alkyl groups. The weak 0—0 bonds break... 

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