Synthesis, polymerization, and properties of the allyl‐functional phthalonitrile

Abstract

A novel bisphthalonitrile monomer containing allyl groups (DBPA‐Ph) had been synthesized via the reaction of diallyl bisphenol A (DBPA) and 4‐nitrophthalonitrile. The chemical structure of DBPA‐Ph was confirmed by 1HNMR, 13CNMR, and FTIR spectroscopy. The curing behaviors and processability of DBPA‐Ph were studied by differential scanning calorimetry (DSC) and dynamic rheological analysis. The monomer manifested a two‐stage thermal polymerization pattern. The first stage was attributed to the polymerization of allyl groups and the second to the ring‐form polymerization of cyano groups. The result of dynamic rheological analysis indicated the monomer had wide curing window and the self‐catalyzed curing behavior. DBPA‐Ph polymers were prepared from the thermal polymerization with short curing time, showing high glass transition temperature (>350°C) and attractive thermal decomposition temperature (>430°C). The outstanding glass transition temperature, desirable thermo‐oxidative stabilities, good processability and sound process conditions could provide more applications to the DBPA‐Ph polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41203.

Properties of microinjection‐molded polypropylene/graphite composites

“…This indicates that sufficient conductive pathways are constructed within corresponding microparts when the LTEG concentration is 30 wt% (i.e., 14.9 vol%), suggesting that lower weight fractions of LTEG fillers are required to obtain enough conductive pathways within molded samples, which is consistent with the findings by Luo et al [22]. According to the literature [22][23][24][25], the in situ exfoliation of LTEG during the melt blending process is essential to the formation of conductive network in polymer composites. In addition, the average particle size of LTEG (about 180 μm) is larger than that of SG (nearly 20 μm).…”

“…6a). The result indicated that the intercalated agents can easily escape from the stacked graphite flakes of LTEG [25] during the melt blending process, thereby increasing the likelihood of forming intact conductive network within resultant composites.…”

“…7. It is clear that intact conductive pathways can be formed within the microparts due to the large particle size and, more importantly, the in situ exfoliation of LTEG during melt processing [23][24][25]. For example, Wu and Drzal [36] found that the polymer composites with larger graphite particle size showed higher thermal conductivity when compared with those with smaller graphite particles, which was attributed to the fact that samples with larger size graphite particles have less contact resistance.…”

“…Graphite, which is naturally abundant or can be synthesized from the petroleum coke or other precursor materials (i.e., synthetic graphite [SG]) [20], is known as a type of cost-effective carbon filler to enhance the transport properties of polymer matrices thanks to its low density and high thermal and electrical conductivity as well as good dispersibility [21]. Recently, it has been reported that the low-temperature expandable graphite (LTEG) is an efficient additive that can significantly enhance the overall thermal and electrical conductivity of thermoplastic polymers at a relatively lower filler concentration when compared with flake graphite (FG) [22][23][24][25]. For example, Luo et al [22] found that the percolation concentration, p c , for LTEG filled high-density polyethylene composites is about 20 wt%, which is half of that obtained from their FG-containing counterparts.…”

Branched phenyl‐s‐triazine moieties to enhance thermal properties of phthalonitrile thermosets

“…Growth in the aerospace, marine and microelectronic industries increasingly requires the development of heat‐resistant materials . Phthalonitrile (PN)‐based resins, as a class of heat‐resistant materials, have sparked great interest and attention, due to their unique properties, including outstanding thermal stability, great flame retardancy, low moisture resistance and excellent mechanical properties . A factor that has impeded the application of neat PNs is their fairly sluggish curing condition .…”