Diallyl Isophthalate Research Articles

Influence of composition and irradiation of the structure and mechanical properties of compositions based on polyamide-610

A study has been made of the influence of diallyl isophthalate and triallyl isocyanurate (crosslinking additives) and talc (artificial centre of structurization), as well as the effect of irradiation, on the structure and mechanical properties of compositions based on PA-610. The effect of the additives on the character of the supermolecular structure is discussed, as well as their influence on crystallinity and on mechanical properties. The change occurring in mechanical properties under irradiation is mainly related to the formation of a three-dimensional network in the amorphous phase. Triallyl isocyanurate was found to be the most effective crosslinking agent in the case of irradiation.

Simultaneous interpenetrating polymer networks of epoxy resin/bismaleimide-allylester copolymer. I. Dynamic mechanical properties

Abstract Simultaneous interpenetrating polymer networks (SINs) were prepared from nadic methyl anhydride-cured epoxy resin and bismaleimide (BMI) coreacted with triallyltrimellitate (TAT), triallylisocyanurate (TAIC), and diallylisophthalate (DAP), under the same gelling conditions for both the epoxide resin and BMI-allylester comonomer. Dynamic mechanical properties of the SINs were measured over the temperature range from room temperature to about 300°C. The rubbery modulus and glass transition temperature (Tg) due to the cured epoxy resin considerably increased with loading of BMI-allylester copolymer. The value of Tg exhibited an asymptotic behavior at high loading, the value increasing in the order of BMI-TAT, -TAIC, and -DAP. The relative modulus in the rubber state shows that phase inversion occurs in the SINs at the concentration of 30–40 wt% BMI-allylester. The increase in Tg with loading can be explained in terms of the contributions of both an increase in crosslink density and an interaction be...

Studies of the polymerization of diallyl compounds. XLI. Discussion of substantially identical gel points among three isomeric diallyl phthalates

AbstractIn the bulk polymerization of three isomeric diallyl phthalates, diallyl phthalate (DAP), diallyl isophthalate, and diallyl terephthalate (DAT), no difference in the actual gel point was substantially observed. This interesting gelation behavior is discussed in terms of the correlation between gelation and the difference in cyclization modes, and the difference in reactivity between the uncyclized and cyclized radicals for crosslinking; the nonconsecutive addition in DAT polymerization led to a delayed gelation and the cyclized radical in DAP polymerization showed an enhanced reactivity for crosslinking.

Molar mass distribution of diallyl 3,6-endomethylene-1,2,3,4-tetrahydrophthalate prepolymer

Gel permeation chromatography was used to study the variation in molar mass distribution during benzoyl peroxide initiated polymerization of diallyl 3,6-endomethylene-1,2,3,4-tetrahydrophthalate in benzene solution. Whilst a linear polymer is formed initially, branched chains begin to predominate at higher conversions. The molar mass distribution of the obtained prepolymer was compared with those of diallyl isophthalate prepolymers and of a series of diallyl carbonates. Chromatograms of all those prepolymers bear the same character. Macromolecules with identical hydrodynamic dimensions elute at the peak maxima.

Molecular mass distribution of diallyl isophthalate prepolymer during polymerization

The change in MMD during the polymerization of diallyl isophthalate in bulk and in benzene solution in the presence of benzoyl peroxide is studied by a GPC method from low degrees of conversion (<1%) up to the formation of microgel and a crosslinked polymer. At the beginning of the process a linear polymer is formed, having the same MM both on polymerization in bulk and in solution. With increase in conversion a branched polymer is formed. The prepolymer has a wide MMD and an MM from 500 up to several million, and its nature depends on the polymerization method. In the case of polymerization in solution, gelation is observed at higher degrees of conversion than in bulk.

Effect of temperature on the structure of prepolymers of diallyl benzenedicarboxylates

The effect of bulk polymerization temperature on the structure of prepolymers of diallyl phthalate (DAP), diallylisophthalate (DAI) and diallylterephthalate (DAT) was investigated in the temperature range of 80°C–285°C. The degree of unsaturation of the prepolymers of each of the monomers unexpectedly increased with temperature in the range above 160°C. The average length of linear CC chain in the prepolymers decreased with temperature. The branching ratio for prepolymers increased with conversion of the monomer at each of the temperatures. The degree of cyclization of monomer units ( P c P ) was always arranged in the order: poly(DAP)>poly(DAI)>poly(DAT). But, contrary to expectations, at temperatures above 160°C the P c P values diminished progressively, which was attributed mainly to the diminished probability of cyclization occurring by chain transfer.

Studies of the polymerization of diallyl compounds. XXV. Gel point in the polymerization of diallyl esters of aromatic dicarboxylic acids

AbstractStudies on gelation in the radical polymerization of diallyl dicarboxylates have been conducted by Simpson,9,11 Gordon,10 and Oiwa.13 However, the results obtained have not always been consistent and are still far from full elucidations. In this paper, the gel point in the polymerization of diallyl aromatic dicarboxylates, including diallyl phthalate (DAP), diallyl isophthalate (DAI), and diallyl terephthalate (DAT) is experimentally reexamined in detail and discussed according to Gordon's theory; the discrepancy between actual and theoretical gel point conversion was quite large and was enhanced in the order DAT &gt; DAI &gt; DAP. Moreover, from detailed inquiry into the primary chain length of the prepolymer it is suggested that the intramolecular chain transfer reaction plays an important role in the polymerization of diallyl ester accompanying the intramolecular cyclization reaction. The polydispersity coefficient (Pw,0/Pn,0) of the initial prepolymer of DAP is also estimated to be 2.0 from the extrapolation of Pw/Pn to zero conversion.

Polyorganosiloxanes with linear and cyclic segments

Hydride transfer to the tricyclic siloxane compound, i.e. 1,7-dimethyl-1,7-divinyl-3,5,9,11-tetraphenyltricyclohexamethylsiloxane, from the α,ω-methylphenyl-siloxane dihydride and the α,ω-dimethylsiloxane hydride oligomers yielded polymers with linear-structure polydiorgano- and polycyclosiloxane segments. Hydride transfer reaction between diallyl isophthalate and the α,ω-dimethylsiloxane dihydride oligomers yielded polymers containing molecules with linear siloxane and aromatic segments. The glass temperatures ( T g) were determined for all the produced polymers. The larger the contents of tricyclic siloxane and also of aromatic segments in the linear siloxane chains, the larger were the T g. The TGA of the polymers showed their resistance to thermal-oxidative degradation to increase with the content of tricyclic siloxane segments and to decrease as the content of aromatic segments increased in the linear siloxane chain.

Optimum diffusion condition in the fabrication of a plastic lenslike medium

The optimum fabrication condition has been found in the preparation of a plastic lenslike medium which has a parabolic dielectric constant distribution. The maximum possible value of the focusing constant g=0.21 mm−1 was obtained for diallyl isophthalate–methylmethacrylate combination with a rod radius r0=1.5 mm.

Water permeability of poly(diallyl isophthalate) films

AbstractThe prepolymer of diallyl isophthalate is employed as a material for a moistureprotective coating which is applied in the solution form, free of radical initiator. The effect of the absence of radical initiator, temperature and time of cure, and thickness of coat is evaluated in terms of the permeability of water through the protective films of the polyphthalate. Temperature of the noncatalytic cure can be as low as 170°C, and the presence of an initiator in the coating formulation does not bring about any improvement in the moisture resistance of the films.

Studies of the polymerization of diallyl compounds. XVI. Copolymerizations of diallyl esters of aromatic dicarboxylic acids with methylallyl benzoate

AbstractRadical copolymerizations of diallyl phthalate (DAP), diallyl isophthalate (DAI), and diallyl terephthalate (DAT) with methylallyl benzoate (MABz) have been carried out in bulk at 60°C, using benzoyl peroxide as initiator.In the copolymerization of DAP with MABz the residual unsaturation of the copolymer decreased with increasing mole fraction of MABz in the feed. In the case of DAI it was nearly constant, regardless of the molar feed ratio, whereas with DAT it tended to increase with increasing mole fraction of MABz in the feed. These results were interpreted by considering the difference of the mode of cyclization in the case of DAP, DAI, and DAT.The following monomer reactivity ratios γ1 (of the uncyclized radical), γc (of the cyclized radical) and γ2 (of the MABz radical) were estimated on the basis of the cyclocopolymerization mechanism. DAP: 0,84; 0,61; 1,08; DAI: 0,76; 0,52; 1,06. For the copolymerization of DAT with MABz the apparent monomer reactivity ratios based on the general copolymer composition equation were obtained as γ1 = 0,79 and γ2 = 1,06.

Copolymerizations of Diallyl Terephthalate with Isophthalate and Allyl Benzoatet

Diallyl isophthalate (DAI) and diallyl terephthalate (DAI) were copolymerized with allyl benzoate (ABz) in bulk at 60°C, using benzoyl peroxide as an initiator.In both copolymerization systems the rate of polymerization and the degree of polymerization of the copolymers tended to decrease with an increase in the mole fraction of ABz in the feed.In the copolymerization of DAI with ABz the residual unsaturation of the copolymer was nearly constant, regardless of the feed molar ratio, while in the copolymerization of DAT with ABz it tended to increase with increasing the mole fraction of ABz in the feed.The apparent monomer reactivity ratios obtained on the basis of the general copolymer composition equation were as follows: M1, r1, r2; DAI, 0.69, 1.02; DAT, 0.77, 0.89.On the other hand, for the copolymerization of DAI with ABz the following monomer reactivity ratios(MRR) were also estimated on the basis of the cyclocopolymerization mechanirn: 7-1=0.77 (MRR of the uncyclized radical), rc=0.52 (MRR of the cyclized radical), r2=1.00(MRR of the ABz radical).These results were discussed in connection with the results of the copolymerization of diallyl phthalate with ABz5.

Reinforced Polymers for High-Temperature Microwave Applications

The rapid progress of aerospace technology relative to ultrahigh-speed aircraft has necessitated a reevaluation of electronic insulation with respect to high-temperature environments. A description of the processes that contribute to polymer degradation is presented to alert the electronic system's engineer to the possible insulation problems arising from high frequency and elevated temperatures. Glass-and quartz-fabric-reinforced polymers are evaluated for application in high-temperature microwave systems. Polyester, diallyl isophthalate, diolefin, epoxy, silicone, polyimide, and poly-benzimidazole laminating systems were investigated. The molding capabilities and laminating conditions of these materials in prepreg form are reviewed with respect to degree of porosity and production difficulty that may be encountered in molding thin, intricately designed parts. To determine the suitability of these laminates for high-temperature ure environments, consideration is given to weight loss and flexural strength as a function of temperature and thermal aging. The compatibility of these composites in microwave applications is determined by measuring their dielectric constant and dissipation actor at 1010 Hz and at various operating temperatures.

Bulk polymerization of certain allyl and acrylic monomers

A REPORT was published in 1963 on the synthesis and properties of unsaturated polyarylates containing allyl groups [lJ wMeh are capable o f giving crosslinked polymers, particularly by copolymerization with monomers. Up to now there has been no detailed information in the literature on copolymerization with any monomeric unsaturated polyesters containing allyl groups. Therefore, considering the properties of polymerization ofallyl monomers in general, prior to studying the copolymerization of unsaturated polyarylates containing allyl groups with certain monomers, it was advisable to investigate the homopolymerization of these monomers in order to determine the main :features of polymerization and evaluate comparative reactivities. We used the following monomers i~ the investigation: methyl methacrylate, styrene, ethylene glycol dimethaerylate, 2,2-di-(4-oxyphenyl)propyl(diane) diacrylate, diane dimethaerylate, diallyl phthalate, diallyl isophthalate and diallyl terephthalate (Table 1). Many detailed investigations are reported in the literature on bulk polymeriza. ¢ion of styrene and methyl methacrylate. Therefore, similar experiments with these monomers were only made to obtain the required data for comparison with other monomers which have been less investigated. Numerous papers have been published in recent years which are devoted ¢o polymerization producing crosslinked polymers. Some of these papers have important theoretical aspects since their object was the quantitative elucidat ion of gel formation, gel effect, eyclization, effect of diffusion, etc. [2-12]. However, these problems have not so far been completely elucidated and there are varying views on the mechanism and laws of three-dimensional polymerization. Of the tetra-functional monomers the glycol dimethacrylates and diacrylates [6, 10, 12-15] and diallyl phthalate [7, 11, 16-19, 21-23] have been studied in most detail. Polymerization of diallyl isophthalate and diallyl terephthalate ,[11, 16, 20], has been studied to a comparatively small extent and the polymers of bisphenol dimethacrylates and diaerylates are only described in patent literatu re [24].