Synthesis of High-Tg, Flame-Retardant, and Low-Dissipation Telechelic Oligo(2,6-dimethylphenylene ether) Resins for High-Frequency Communications

Abstract

An intrinsic flame-retardant moiety, 9,10-dihydro-9oxa-10-phosphaphenanthrene-10-oxide (DOPO), is incorporated into oligo(2,6-dimethyl-1,4-phenylene ether) (OPE), and four phosphorus-containing telechelic OPE resins are synthesized. The first is synthesized with a para phenyl methacrylate end group (OPE-PM); the second is synthesized with para and meta phenyl methacrylate end groups (OPE-OPM); the third is synthesized with a para vinyl benzyl ether end group (OPE-VBE); and the fourth is synthesized with para and meta vinyl benzyl ether end groups (OPE-OVBE). All the self-cured samples showed good flexibility, high temperature (T g = 216 to 250 °C, T d5% > 400 °C), and water resistance (0.25%). The self-cured OPE-OPM and OPE-OVBE show outstanding low dielectric values of 2.63 and 2.65 and impressive low dissipation factors of 0.0035−0.0047 at 10 GHz, respectively. The results indicate that a further crosslinking behavior in the chain end can enhance the rigidity and further enhance the dielectric properties. Most importantly, all phosphinated thermosets show excellent burning resistance, and both UL-94 VTM and microscale combustion calorimetry experiments were conducted to explain the flame-retardant behavior. We believe that this work will contribute greatly to the research related to polymeric substrate materials for 5G technology.

Study on Silicon-Containing Main Chain Type Polybenzoxazines with Both High Heat Resistance and Low Dielectric Constant

“…Figure and Table S1 show comparisons of T g s and dielectric constants of different polybenzoxazines with low dielectric constants in the references. ,− The T g and dielectric constant of a typical polybenzoxazine, poly­(BA-a), are 190 °C and 3.55, respectively . Compared with poly­(BA-a), other polybenzoxazines show lower dielectric constants and higher T g s. For example, the dielectric constant of the sample in ref is as low as 2.2, and its T g is 216 °C.…”

Graft Architectured Poly(phenylene oxide)-Based Flexible Films with Superior Dielectric Properties for High-Frequency Communication Above 100 GHz

“…Furthermore, the thermal stability of pristine PPO should be enhanced when considering the microelectronics manufacturing process . Recently, several groups modulated the structures of PPO and developed PPO-based flexible dielectric film with enhanced processability and excellent thermal and dielectric properties. ,− For example, Chen et al synthesized cross-linkable PPO by copolymerizing 2,6-dimethylphenol and 2,6-diphenylphenol and fabricated cross-linked PPO films with desired balance of flexibility and thermal resistance . Fang et al modified PPO by introducing anethole as cross-linkable side chains, allowing the fabrication of PPO films with improved thermomechanical properties and good dielectric performance at a moderate frequency (3 MHz) .…”

Esterification Oligomerization of Phosphaphenanthrene Biphenol Caused Efficient Flame Retardant Effect of Group Aggregation in Epoxy Resin

“…As one of the efficient flame retardant groups, phosphaphenanthrene group can quench free radical chain reactions in the gas phase during combustion. 12,13 6H-Dibenz(C,E)(1,2)oxaphosphorin-6-oxide (DOPO) and 2-(6-oxid-6H-dibenzo-[c,e][1,2]oxaphosphorin-6-yl)-1,4-benzenediol (DOPO-HQ) with phosphaphenanthrene structures have a considerable position in the field of flame retardant polymer materials. 14,15 Some DOPO derivatives have been reported as effective flame retardants in epoxy resin.…”

“…As one of the efficient flame retardant groups, phosphaphenanthrene group can quench free radical chain reactions in the gas phase during combustion. , 6 H -Dibenz­(C,E)­(1,2)­oxaphosphorin-6-oxide (DOPO) and 2-(6-oxid-6 H -dibenzo­[c,e]­[1,2]­oxaphosphorin-6-yl)-1,4-benzenediol (DOPO-HQ) with phosphaphenanthrene structures have a considerable position in the field of flame retardant polymer materials. , Some DOPO derivatives have been reported as effective flame retardants in epoxy resin . For example, the P–H bond of DOPO can react with a Schiff base, unsaturated double bond, , and carbonyl group to prepare curing agents of epoxy resins; the additive-type flame retardants were synthesized by combining the phosphaphenanthrene group and other groups with a flame retardant feature. − In addition, the flame retardancy of some phosphorous polyester compounds prepared by DOPO or its derivatives have been widely studied.…”