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Unsaturated polyesters experimental

Cole reviews the nse of Raman spectroscopy to monitor the curing of different thermoset composite polymer systems, thongh he cautions that it is not suitable for certain materials [215]. Cruz et al. studied the effect of elevated pressure on the cure rate and the degree of cnre of unsaturated polyester and other thermoset materials [216,217]. The approach worked well, though the experimental set up required addi-... [Pg.224]

Arylcarbonyl Compounds as Initiators for Unsaturated Polyester/ Styrene Copolymerization Systems. Gel Time Determination and Reaction Curves. Ten blanks (gel time of 20 grams Vestopal A without initiator) gave a mean deviation from the average of 3.3% and a maximum deviation of 7.2%. Five measurements with l-phenyl-2-propanone as initiator gave a mean deviation from the average of 3.3% and a maximum deviation of 7.7%. An experimental error of 10% was therefore assumed and proved correct by spot checks. The exceptions (not used in the discussions) are most probably caused by the insolubility of the initiators in the reaction medium. [Pg.64]

Differential scanning calorimetry (DSC) was used in investigating the curing kinetics of the unsaturated polyester resin. For the study, we used a DuPont 1090 Thermal Analyzer, equipped with a 910 DSC Module. Indium was used for temperature and calorimetric calibrations, following the procedure described in the operating meinual of the instrximent. The experimental procedure employed is very similar to that described in the literature (8-13) cind we have discussed it elsewhere (14). [Pg.205]

An almost complete agreement between experimental and calculated (Eq. (16)) dependences of conversion on time, /S(t), is obtained for curing of epoxy [63, 114], epoxy silicone [19], silicone oligomers [20, 109], low-molecular-weight silicone rubbers [46, 105], unsaturated polyester [97, 121], melamine-formaldehyde [122], methylolpolyamide [123] and carbamide resins [122]. [Pg.245]

It is interesting to note that Eq. (28) is sufficiently general and describes well the kinetics of curing of fundamentally different systems with phase segregation like, for example, unsaturated polyester resin. This is shown in Fig. 32 where there are compared experimental data of Ref. [129] and curves calculated by Eq. (28). [Pg.250]

The experimental unsaturated polyester resins used in this study were supplied by several chemical companies since the PET chemical conversion into unsaturated polyester could not be done at the University of Texas laboratories. These resins were prepolymers with high viscosity. They were therefore diluted with styrene to reduce their viscosity and allow their further cure to a solid (polymer) upon the addition of suitable free radical initiators and promoters. The typical styrene content varied between 30 to 40% of the total resin weight, and viscosities were in the range of 100 to 1000 cps. [Pg.10]

Similar plots can be obtained from kinetic data of unsaturated polyester resins (24, 25). This behavior is independent of the identity of the nitrogen substituents of the amine or the monomer. Previous publications from this laboratory have pointed out that the a+ value of the amine ring substituent yielding maximum reactivity, i.e., minimum polymerization (or cure) time, occurs at approximately -0.2 in the cases examined (26-29). The optimum value is anticipated to be fairly insensitive to the type of monomer and experimental conditions. [Pg.363]

Figure 2.16 Unsaturated polyester molecular weight effects on the experimental T versus composition cloud point curves of a UPE resin. Study on resins of similar chemical structure and fonr molecnlar weights (620,1205,1700 and 2740 g/ mole) indicated that UPE miscibility in styrene changed in the following order 1700>1205>2740>620. Reprodnced with permission from F. Baffa and J. Borrajo, Journal of Applied Polymer Science, 2006,102, 6064 2006,... Figure 2.16 Unsaturated polyester molecular weight effects on the experimental T versus composition cloud point curves of a UPE resin. Study on resins of similar chemical structure and fonr molecnlar weights (620,1205,1700 and 2740 g/ mole) indicated that UPE miscibility in styrene changed in the following order 1700>1205>2740>620. Reprodnced with permission from F. Baffa and J. Borrajo, Journal of Applied Polymer Science, 2006,102, 6064 2006,...
In their modeling of unsaturated polyester resin formation, Beigzadeh et al. [100] and Zetterlund et al. [101] have also found the Chen-Wu relationship more useful than the rather cumbersome empirical models of Paatero et al. [102] or Leh-tonen et al. [103]. Zetterlund et al. [101] have also presented interesting experimental data on the simultaneous self- and cross-catalysis by two carboxyl groups, namely those formed by the addition of maleic and phthalic anhydride to 1,2-propanediol they show there is an anti-synergistic effect that is, the total rate reaction of the two carboxyl groups is lower than the sum of the rates of reaction of the individual acids with the same concentration and at the same temperature. [Pg.87]

UP Unsaturated polyester Reproduced with permission from M.S. Helal in Experimental Study of Mechanical Properties and Structural Applications of Polymer Concrete, University of Texas, Austin, TX, USA, 1990 [PhD Thesis], 1990, University of Texas [17] ... [Pg.52]

To analyze experimental data, Lee and Han (1987a) employed a WLF expression to describe the viscosity of unsaturated polyester ... [Pg.662]

Using Eq. (14.13), we can now predict the viscosity of unsaturated polyester during cure once information on a during cure is available to us. In order to use Eq. (14.13) to describe the variation of r/ during cure of unsaturated polyester, one must have an expression describing the kinetics of the cure reactions. Below, we present experimental methods that can be used to determine an expression for cure kinetics. [Pg.664]

The kinetic features were studied experimentally and theoretically for IPNs made of PU and unsaturated polyester (PE) [266]. In this case the PU component formed from diisocyanate, polyol, and diol consists of rigid and soft segments. The PE component was synthesized by copolymerization of unsaturated PE with styrene. The grafting of both components is possible through reaction between NCO groups with the end OH or COOH groups of the PE molecule. Such systems can be considered as grafted, which is schematically presented in Scheme 1. [Pg.151]

Other polyamides produced experimentally include polymers with active lateral groups (hydroxy, keto groups etc.), polymers with heteroatoms (sulphur and oxygen) in the polyamide-forming intermediates, polymers with tertiary amino groups in the main chain and polymers with unsaturation in the main chain. There does not, however, appear to have been any serious attempt to develop unsaturated polyamide analogues to the polyester laminating resins. [Pg.509]

The final properties depend not only on unstaturated polyester structure but also on a number of other parameters, such as the nature and proportion of unsaturated comonomer, the nature of the initiator, and the experimental conditions of the crosslinking reaction. Moreover, since polyester resins are mainly used as matrices for composite materials, the nature and amount of inorganic fillers and of reinforcing fibers are also of considerable importance. These aspects have been discussed in many reviews and book chapters and are beyond the scope of this chapter.7-9... [Pg.59]

IPNs are found in many applications though this is not always recognised. For example conventional crosslinked polyester resins, where the polyester is unsaturated and crosslinks are formed by copolymerisation with styrene, is a material which falls within the definition of an interpenetrating polymer network. Experimental polymers for use as surface coatings have also been prepared from IPNs, such as epoxy-urethane-acrylic networks, and have been found to have promising properties. [Pg.154]


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See also in sourсe #XX -- [ Pg.89 , Pg.90 ]

See also in sourсe #XX -- [ Pg.89 , Pg.90 ]




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Unsaturated polyesters

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