POLYISOPROPYL

PVDF is among the few semicrystalline polymers that exhibit thermodynamic compatibility with other polymers,80 in particular with acrylic or methacrylic resins.81 The morphology, properties, and performance of these blends depend on the structure and composition of the additive polymer, as well as on the particular PVDF resin. These aspects have been studied and are reported in some detail in Reference 82. For example, polyethyl acrylate is miscible with polyvinylidene fluoride, but polyisopropyl acrylate and homologues are not. Strong dipolar interactions are important to achieve miscibility with PVDF, as suggested by the observation that polyvinyl fluoride is incompatible with polyvinylidene fluoride.83... 

Benzene was alkylated with crude propylene, using H2SO4 of strength from 75 to 97%. The spent acid was recycled in part. With equal moles of benzene and propylene, 25% by weight of acid based on benzene gave 35% isopropyl and 35% polyisopropyl benzene, while 100% acid gave 40% isopropyl and 50% polyisopropyl benzene. With 0.5 mole propylene per mole benzene, all the propylene was consumed and the ratio of mono- to polypropyl benzenes was independent of the acid ratio. 

The second part of this symposium, conducted jointly by the Division of Rubber Chemistry and the Division of Polymer Chemistry of the American Chemical Society, was devoted to methods for measuring the tacticity and the kinetics of polymerization of a variety of materials such as the higher aldehydes, polypropylene oxide, and 4-methylpentene-l. High resolution nuclear magnetic resonance has been particularly valuable in characterizing the structures of polyacetaldehyde and polyisopropyl acrylate. 

Polyisopropyl acrylate degradation has been examined by Grassie and Speakman [36] using a bulk technique with low temperature heating at 265 °G. The major products were reported to be carbon dioxide and propylene with small amounts of carbon monoxide and isopropylene. It was reported that no chain fragment fractions, as experienced with other primary esters, were produced. 

With poly-n-propyl acrylate a greater amount of monomer was produced than with the polyisopropyl ester and as expected from the mechanism proposed, the proportion of propane was much lower with the polymeric normal ester compared with amounts of polypropylene from the polymeric isoester. 

The predominant products resulting from degradation of the polyisopropyl acrylate were considered to be a mixture of saturated and unsaturated trimer as prominent appropriate peaks. This is indicative of ion fragments and directly comparable with similar fragments of other esters studied. 

While the aluminium chloride catalyst enables the reaction to be carried out at 80-100 C temperature, there are inherent problems with this catalyst such as, complex formation with polyisopropylated products, short catalyst life, require large amount of catalyst, it is not recycled, problem in disposing the waste catalyst complex, and polluting problems. 

Cumene Processes. Current processes now used to produce cumene are similar to those that produce ethylbenzene. Monsanto found that its ethylbenzene process was also applicable to produce cumene but with slightly different operating condition. The modified conditions are temperatures less than 135°C and pressure of about 50 psig (46). Monsanto-type processes are used at several plants. Unreacted benzene and poly-isopropyl benzenes are separated from the reaction products and then recycled to the reactor. Eventually, all of polyisopropyl benzenes react to give cumene, so overall yields are typically 97-98%. 

A combination of self-adhesive Eudragit E film with antibacterial drug-loaded polyisopropyl acrylamide microgel beads was designed as a wound dressing. The influence of microgel beads on tack properties was determined. 24 refs. 

Comparisons of isotactic, syndiotactic and atactic polymers also cause problems of explanation. For many polymers the type of tacticity appears to have little effect on Tg. Exceptions are provided by the methacrylate polymers and, in contrast to other acrylates, polyisopropyl acrylate. 

Time of flight static secondary ion mass spectroscopy (SSIMS) has been applied to perfluorinated polymers, polystyrene, polyacylacrylates (including poly cyclo-hexylmethacrylate, polybenzyl methacrylate, polyphenyl methacrylate, poly n-hexyl methacrylate, poly n-butyl methacrylate, polymethylmethacrylate, poly n-propyl methacrylate, polyisopropyl methacrylate and poly secbutyl methacrylate). Blends of polystyrene and polyvinyl chloride, bisphenol A and polystyrene, polycarbonate and polystyrene and tetramethyl bisphenol A and polycarbonate have also been studied by this technique. 

The thermal properties of polyisopropyl acrylamide, polymethacrylic acid, isopropyl acrylamide-methacrylic acid copolymers and their blends were investigated by DSC and TGA. The state of the water was studied on the basis of DSC traces of swollen samples. The Tg of the same series of materials was also measured. 64 refs. 

Table 4.1 Degradation Products and Yields of Poly- -Propyl Acrylate and Polyisopropyl Acrylate ...

---