32 research outputs found
POLY TRI (ETHYLENEGLYCOL) DIMETHACRYLATE NETWORK OBTAINED BY FRONTAL ATOM TRANSFER RADICAL POLYMERIZATION
POLY TRI (ETHYLENEGLYCOL) DIMETHACRYLATE NETWORK OBTAINED BY FRONTAL ATOM TRANSFER RADICAL POLYMERIZATION
Frontal atom transfer radical polymerization of tri(ethylene glycol) dimethacrylate
The first frontal atom transfer radical polymerization (FATRP) has been successfully carried out using tri(ethylene glycol) dimethacrylate as a monomer. The effect of the catalyst/initiator ratio has been investigated and related to the front velocity and its maximum temperature. By comparing this new approach with classical radical polymerization routes and with conventional frontal polymerization, it was found that the so-obtained polymer is characterized by higher conversion, shorter reaction times, higher degradation temperature, and does not contain entrapped bubbles
Synthesis and characterization of unsaturated polyester resins cured by frontal polymerization
Various crosslinking agents have been used to frontally cure the unsaturated polyester derived by the reaction of maleic anhydride and 1,2-propanediol. The effect of composition of the curing mixture on the front velocity and its maximum temperature, as well as on the thermal properties of the obtained materials, is described
Frontal polymerization of diurethane diacrylates
This work deals with the preparation of poly(urethane acrylates) by using two different polymerization techniques. Namely, the classical batch procedure has been compared with frontal polymerization (FP). A thorough study on the effect of initiator type, concentration, and on the velocity of the front and its maximum temperature has been carried out. Moreover, two different synthetic ways have been studied: the one step poly(urethane acrylate) preparation starting directly from 1,6 diisocyanato hexane and 2-hydroxyethyl acrylate, and the two step procedure consisting of the synthesis of the corresponding diurethane diacrylate and of its subsequent polymerization. The first method has the advantage of being faster but some caution is necessary due to the excessive heat that is generated if the reaction conditions are not properly chosen. The second approach requires a further step but has the advantage of being more controlled. DSC analysis did not show any significant difference by comparing the thermal properties of the materials obtained by the two techniques (batch and FP). However, since FP runs are very easy and fast to be performed, FP should be seriously taken into proper account when these materials have to be prepare
La produzione di piastrelle a base di aggregati di ardesia mediante tecnologie innovative
Frontal polymerization of diurethane diacrylates
This work deals with the preparation of poly(urethane acrylates) by using two different polymerization techniques. Namely, the classical batch procedure has been compared with frontal polymerization (FP). A thorough study on the effect of initiator type, concentration, and on the velocity of the front and its maximum temperature has been carried out. Moreover, two different synthetic ways have been studied: the one step poly(urethane acrylate) preparation starting directly from 1,6 diisocyanato hexane and 2-hydroxyethyl acrylate, and the two step procedure consisting of the synthesis of the corresponding diurethane diacrylate and of its subsequent polymerization. The first method has the advantage of being faster but some caution is necessary due to the excessive heat that is generated if the reaction conditions are not properly chosen. The second approach requires a further step but has the advantage of being more controlled. DSC analysis did not show any significant difference by comparing the thermal properties of the materials obtained by the two techniques (batch and FP). However, since FP runs are very easy and fast to be performed, FP should be seriously taken into proper account when these materials have to be prepared