Synthesis and characterization of asymmetric bismaleimide oligomers with improved processability and thermal/mechanical properties

Abstract

Novel asymmetric bismaleimide (BMI) oligomers with different molecular weights and dianhydrides were designed and synthesized by 3,4′‐oxydianiline (3,4′‐ODA), 2,3,3′,4′‐oxydiphthalic dianhydride (a‐ODPA), and 2,3,3′,4′‐biphenyltetracarboxylic dianhydride (a‐BPDA). The chemical structures of BMI oligomers were confirmed by Fourier transform infrared spectrometry (FTIR) and gel permeation chromatography (GPC). X‐ray diffraction (XRD) exhibited broad peaks, suggesting amorphous structures. Heat flow curves of oligomers measured by differential scanning calorimeter (DSC) displayed wide processing window due to low glass transition temperatures (Tg). BMI oligomers exhibited high solubility in common organic solvents. Particularly, the OD‐BMI‐1 oligomer exhibited excellent solubility of more than 50 wt% in DMAc solvent. Tg value and minimum complex viscosity of OD‐BMI‐1 oligomer were only 121 °C and 8.1 Pa · s, respectively. The cured BMI resins possess high thermal and thermal‐oxidative stability. The Tg and the temperature of 5% weight loss in nitrogen were above 256 and 449 °C, respectively, and the residual weight percentages at 800 °C were all >49%. Moreover, films made of BMI resins exhibited excellent mechanical properties flexibility, as confirmed by photograph and DMA results of films. The elongation at break of the prepared films was found to be high (almost >9.6%). POLYM. ENG. SCI., 59:2265–2272, 2019. © 2019 Society of Plastics Engineers

Low Dielectric Constant Characteristics of Styrene and Maleimide Anhydride Copolymer with Modification for High Frequency Application of Printed Circuit Board

“…The SMA copolymer was synthesized using aromatic and anhydride monomer by chain polymerization under a thermally working condition. The final molecular structure could be formed with a randomly mixed copolymer or partial block polymer [20][21][22][23]26].…”

“…Therefore, the dropwise introduction of the MA was inevitable in this study to ensure there was sufficient time to modify the random SMA copolymer. In addition, the complete random copolymer of irregular carbon chain structure was formed by using individual monomers having a similar molecular reaction activity, respectively [19][20][21][22][23]26]. The irregular orientation of carbon chains was clearly identified in Table 3, as all ratios of SSS of the unmodified (0.791), acrylate modified (0.186), and bismaleimide (0.187) modified SMAs were significantly different from alternating SMA copolymers having the discrete electron donor (ST) and acceptor (MA) complex identified in the NMR 13 C peak shift analysis [11,12,14].…”

“…The very strong tendency to form alternating ST and MA or bismaleimide could have been successfully deviated by several methods, such as controlled radical polymerization (CRP), including the introduction of nitroxide, and reversible addition-fragmentation transfer (RAFT) polymerization [17,18]. Frequently, the alternation of ST and MA during copolymerization from its electron donor-acceptor complex should be avoided to enhance the miscibility of the SMA as a compatibilizer or binder for the copper clad layer (CCL) of the PCB [19][20][21][22][23].…”

Progress on Polymer Composites With Low Dielectric Constant and Low Dielectric Loss for High-Frequency Signal Transmission

“…Ping Yu et al used 3,4'-ODA), 2,3,3',4'-biphenyl tetracarboxylic dianhydride (a-BPDA) and 2,3,3',4'-Oxydiphthalicanhydride (a-ODPA) as raw materials, synthesizing a new asymmetric bismaleimide oligomers with different molecular weights and dianhydride (Yu et al, 2019). Oligomers have high solubility and solubility stability in common organic solvents.…”

Curing kinetics, thermal and erosive wear characteristics of bismaleimide blends modified by polyaryletherketone

“…Over the past few decades, various attempts have been made to improve the performances of BMI resins, including (1) linear chain extension using aromatic diamines, (2) blending with thermosetting resins, (3) synthesis of new BMI monomers with flexible or long segments in the backbone, (4) rubber toughening, (5) copolymerization of allyl-type compounds, (6) thermoplastic resin modification, and so on. [11][12][13][14][15][16] The disadvantage of the first three methods is that the glass transition temperature (T g ) and the rigidity of cured resins were lowered, however, not only the toughness of BMI resin was improved but the high heat resistance was maintain through the copolymerization with allyl compounds, which is the most reliable method to reduce the brittleness of BMI resin and improve its processing characteristics. Diallyl bisphenol A is considered to be the most popular allyl-type compounds to modify BMI resins, and remarkable achievements have been made in this regard.…”