新型含硼苯并噁嗪的合成及其与环氧树脂共混热性能

以乙醇胺、硼酸为原料合成硼酸乙醇胺酯（BAE）,再用所得硼酸乙醇胺酯与多聚甲醛、苯酚反应,合成含硼苯并噁嗪（BAE-BOZ）。将所得BAE-BOZ高温固化,BAE-BOZ和环氧树脂E-51按照不同的质量比进行熔融共混,并经高温固化。采用FT-IR,¹H NMR 和¹³C NMR等分析了BAE-BOZ的化学结构,证明了产物为目标产物;采用DSC对BAE-BOZ的固化特性进行研究;采用TG 分析了含硼乙醇胺型苯并噁嗪poly（BAE-BOZ）和BAE-BOZ/E-51共聚物的热稳定性。结果表明：BAE-BOZ在218℃出现了固化峰;BAE-BOZ的硼含量达到8.67%,在N₂条件下,poly（BAE-BOZ）的热分解温度为302℃,在426℃时热分解速率最快,800℃的残炭率为58.08%,与未经硼改性的乙醇胺型苯并噁嗪（E-BOZ）相比,热分解温度提高40℃,残炭率提高了16.28%;BAE-BOZ/E-51共聚物的热分解温度达到343℃,热性能得到进一步提高。     

含DOPO的双酚A-单苯并(口恶)嗪合成、表征及其固化特性

以双酚A、苯胺、多聚甲醛为原料,合成了双酚A-双苯并(口恶)嗪（DBOZ）,再用其与DOPO（9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物）反应,合成了含DOPO的双酚A-单苯并(口恶)嗪（DBDO）。采用红外、核磁共振（氢谱核磁共振和碳谱核磁共振）等分析手段对DBOZ和DBDO的化学结构进行了表征;采用差示扫描量热仪对DBOZ和DBDO的固化特性进行研究,使用热重分析分析了所得聚苯并(口恶)嗪的热稳定性。结果表明：在N₂气氛中,DBOZ在205℃左右开环聚合,热分解温度为312℃,在373℃分解速度达到最快,在800℃时的残碳率为37.19%;在N₂气氛中,DBDO的热分解温度为353℃,在443℃分解速度达到最快,在800℃时的残碳率为39.60%。     

Synthesis and characterization of a novel acetylene‐ and maleimide‐terminated benzoxazine and its high‐performance thermosets

A novel acetylene‐ and maleimide‐terminated benzoxazine, 3‐(3‐ethynylphenyl)‐3,4‐dihydro‐2H‐6‐(N‐maleimido)‐1,3‐benzoxazine (MBZ‐apa), was successfully synthesized with N‐(4‐hydroxyphenyl)maleimide, paraformaldehyde, and 3‐aminophenylacetylene. The structure of the benzoxazine is confirmed by FTIR and ¹H‐NMR spectroscopies. MBZ‐apa is easily dissolved in common organic solvents. Differential scanning calorimetry (DSC) was used to study thermal cross‐linking behavior of MBZ‐apa. The DSC curve shows only a single exothermic peak due to the oxazine ring‐opening polymerization and the polymerization of the acetylene and maleimide groups occurring simultaneously in the same temperature range. Dynamic mechanical analyses (DMA) reveals that the novel polybenzoxazine exhibits high glass‐transition temperature (T_g) (ca. 348°C). The storage modulus arrives at 4.5 GPa in the range of room temperature to 330°C. The polybenzoxazine exhibits good thermal stability as evidenced by thermogravimetric analysis (TGA). Pyrolysis‐gas chromatography/mass spectrometry (Pyrolysis‐GC/MS) was employed to characterize the polybenzoxazine. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis,polymerization and thermal properties of bio-based benzoxazine resins containing imide or amide functionality

Two novel bio-based benzoxazine monomers containing imide or amide group (HPIDD-fa and HPBA-fa) were synthesized from raw materials of benzoyl chloride/phthalic anhydride, tyramine, furfurylamine and paraformaldehyde via a two-step reaction. Fourier transform infrared spectroscopy (FT-IR), proton and carbon nuclear magnetic resonance (NMR) spectroscopies were performed to characterize the structures of the benzoxazine monomers. The curing behavior was investigated by using differential scanning calorimetry (DSC) and in situ FT-IR, and the DSC results indicate that the peak curing temperatures of HPIDD-fa and HPBA-fa are centered at 248.5 and 230.1°C, respectively. In addition, thermogravimetric analysis (TGA) suggests that the newly developed bio-based benzoxazine-derived polybenzoxazines present excellent thermal stability with T_d10 (temperature at 10% weight loss) of 385 and 368°C for poly(HPIDD-fa) and poly(HPBA-fa), respectively. The current investigation suggests that our newly obtained bio-based thermosetting resins are promising materials for high-tech applications.     

Synthesis,characterization of new carboxylic acid‐containing benzoxazine and its cocuring behaviors with bisoxazoline

A new benzoxazine‐benzoic acid (BBA) was synthesized and the structure was conformed by ¹H‐NMR, ¹³C‐NMR, FTIR, etc. The cure behavior of BBA and cocure behavior of BBA with phenylene bisoxazoline (1,3‐PBO) were investigated by differential scanning calorimetry (DSC). It was found that BBA showed a single curing exothermic peak at about 217°C. However, all BBA/1,3‐PBO systems exhibited two exothermic peak. One may be attributed to the reaction between carboxyl groups of BBA and 1,3‐PBO. And the other was attributed to the ring‐opening polymerization of oxazine rings and the reaction between phenolic hydroxyl groups generated by the ring opening of benzoxazine ring and 1,3‐PBO. The curing temperature of benzoxazine containing carboxyl groups could be lowered by the copolymerization of 1,3‐PBO. Thermogravimetric analysis showed that the incorporation of ester–amide groups had a significant effect on decreasing thermal stability and char yield of the cured resin. SEM results indicated that 1,3‐PBO could toughen BBA benzoxazine resin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of a novel benzoxazine precursor containing phenol hydroxyl groups and its polymer

A novel benzoxazine precursor containing phenol hydroxyl groups was synthesized from bisphenol A, 4,4′‐diaminodiphenyl methane, and formaldehyde with a molar ratio of 2:1:4. The benzoxazine precursor was characterized with Fourier transform infrared, proton nuclear magnetic resonance, and size exclusion chromatography. The curing reaction was monitored by the gel time, differential scanning calorimetry, and Fourier transform infrared. The obtained polybenzoxazine showed high thermal stability and a high glass‐transition temperature. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and properties of a novel bio‐based benzoxazine resin with excellent low‐temperature curing ability

A novel bio‐based benzoxazine resin (diphenolic acid/furfurylamine benzoxazine resin, PDPA‐F‐Boz) was prepared by using bio‐based diphenolic acid, furfurylamine and paraformaldehyde as raw materials. The structure of DPA‐F‐Boz monomer was characterized by Fourier transform infrared spectroscopy, ¹H NMR and ¹³C NMR, and then its curing reaction and the thermal stability of the cured PDPA‐F‐Boz were analyzed. Compared with the traditional fossil‐based benzoxazine (bisphenol A/aniline benzoxazine, BPA‐A‐Boz) and the bio‐based benzoxazine (diphenolic acid/aniline benzoxazine, DPA‐A‐Boz), DPA‐F‐Boz monomer showed the lowest curing temperature, and PDPA‐F‐Boz had the highest residual char ratio at 800 °C and the lowest degradation rate at the peak temperature. Meanwhile, the total heat release, peak heat release rate and heat release capacity of PDPA‐F‐Boz were much lower than those of PBPA‐A‐Boz and PDPA‐A‐Boz. Thus, PDPA‐F‐Boz showed excellent low‐temperature curing ability and thermal stability. © 2019 Society of Chemical Industry     

Synthesis and characterization of novel main-chain benzoxazines containing cycloaliphatic and aliphatic structures and their thermal and dielectric properties

With the rapid development of ultra-large-scale integrated circuits and aerospace, the demand for materials with excellent overall performances is on the rise. In this study, we have successfully synthesized novel main-chain benzoxazine precursors ((BPA-AD/dd1)_main) containing both cycloaliphatic and aliphatic structures by employing adamantanediamine and Priamine 1074 for the first time, and their chemical structures and polymerization behaviors were characterized using Fourier transform infrared spectroscopy (FT-IR), NMR spectroscopy (¹H-NMR) and differential scanning calorimetry (DSC). The results showed that the exothermic onset of the (BPA-AD/dd1)_main shifted to lower temperatures with an increasing molar ratio of Priamine 1074. Furthermore, the thermal properties, dielectric properties, surface hydrophobicity, and tensile properties of P(BPA-AD/dd1)_main films were explored via dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), contact angle measuring instrument, an impedance analyzer and universal testing machine. The molar ratio of Priamine 1074 and 1,3-Bis(4-anilino)-adamantane (AD) significantly influenced the thermal properties, dielectric properties, and surface hydrophobicity of P(BPA-AD/dd1)_main. P(BPA-AD 0.75)_main exhibited a high T_g of 296.8°C, excellent dielectric properties (Dk = 2.58 and Df = 0.0055 @ 10 MHz), and large water contact angle as high as 105.8°, qualifying it as a potential candidate for interlayer materials in ultra-large-scale integrated circuits and resin matrix in high-performance composites.     

Preparation,characterization, and polymerization of novel maleimidobenzoxazine containing carboxylic moiety and its cocuring behaviors with epoxy resin

A novel benzoxazine containing maleimide and carboxylic moieties, 1‐[3‐(4‐carboxylphenyl)‐3,4‐dihydro‐2H‐benzo[e][1,3]‐oxazin‐6‐yl]maleimide (Mal‐Bz‐Co), was synthesized and the structure was identified by ¹H‐NMR and FTIR. Mal‐Bz‐Co exhibited good solubility in common organic solvents. The cure behavior of Mal‐Bz‐Co and cocure behavior of Mal‐Bz‐Co with o‐cresol formaldehyde epoxy resin were investigated by differential scanning calorimetry. Results indicated that Mal‐Bz‐Co showed a single curing exothermic peak at about 238.3°C. However, the maximum curing temperature (T_p) decreased to 146.1°C when Mal‐Bz‐Co cocured with o‐cresol formaldehyde epoxy resin in the molar ratio of 1 : 1. The T_p was about 92°C lower than that of Mal‐Bz‐Co. Thermogravimetric analysis showed that high‐decomposition temperature and char yield were observed for the cured resins of Mal‐Bz‐Co and Mal‐Bz‐Co/o‐CFER. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of novel polyurethanes containing dioxybenzylidenecyanoacetate,as non‐linear optical chromophores and their properties

Methyl 3,4‐di‐(2′‐hydroxyethoxy)benzylidenecyanoacetate (3) was prepared by hydrolysis of methyl 3,4‐di‐(2′‐vinyloxyethoxy)benzylidenecyanoacetate (2). Diol 3 was condensed with 2,4‐toluenediisocyanate, 3,3′‐dimethoxy‐4,4′‐biphenylenediisocyanate, and 1,6‐hexamethylenediisocyanate to yield polyurethanes 4, 5 and 6 containing the non‐linear optical (NLO) chromophore 3,4‐dioxybenzylidenecyanoacetate. The resulting polyurethanes 4–6 were soluble in common organic solvents such as acetone and DMF. T_g values of the polymers obtained from DSC thermograms were in the range 80–102 °C. Polymers 4–6 showed thermal stability up to 300 °C in TGA thermograms, and electro‐optic coefficients (r₃₃) of the poled polymer films were in the range 10–12 pm V^?1 at 633 nm, which are acceptable for NLO device applications. © 2002 Society of Chemical Industry     

Studies on the curing kinetics and thermal stability of diglycidyl ether of bisphenol‐A using mixture of novel,environment friendly sulphur containing amino acids and 4,4′‐diaminodiphenylsulfone

This article describes the curing behavior of diglycidyl ether of bisphenol‐A using Cysteine (A)/ Methionine (B)/Cystine (C)/ mixture of 4,4′‐diaminodiphenyl sulfone (DDS) and Cysteine/DDS and Methionine/DDS and Cystine in various molar ratios as curing agent. Differential scanning calorimetry was used to study the cure kinetics by recording the DSC scans at heating rates of 5, 10, 15, and 20°C/min. The peak exotherm temperature was found to be dependent on the heating rate, structure of the amino acids and on the DDS/amino acids molar ratio. A broad exotherm was observed in the temperature range of 150–245°C (EA), 155–240°C (EB), and 190–250°C (EC). Curing of DGEBA with mixture of amino acids and 4, 4′‐diaminodiphenyl sulfone (DDS) resulted in a decrease in characteristic curing temperatures. Activation energy of curing reaction is determined in accordance to Ozawa's method and was found to be dependent on the structure of the amino acids and on the ratio of 4,4′‐diaminodiphenyl sulfone (DDS) to amino acid. Thermal stability of the isothermally cured resins was evaluated using dynamic thermogravimetry in nitrogen atmosphere. No significant change has been observed in the char yield of all the samples, but it was highest in the system cured using either Cystine alone (EC‐1) or a mixture of DDS/Cystine (EC‐2, EC‐3, and EC‐4). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Development of novel functional conducting elastomer blends containing butyl rubber and low‐density polyethylene for current switching,temperature sensor,and EMI shielding effectiveness applications

A new class of functional conductive butyl rubber (IIR) with different loadings of low‐density polyethylene (PE) was prepared by roll mixing in a milling at a rotor speed of 24 rpm. To understand the filler dispersion and filler/matrix interaction, the network structure of the specimens was examined by evaluating of the crosslinking density, volume fraction of elastomer, interparticle distance among conductive phases, interfacial area per unit volume, torque rheometer, hardness, tensile strength, elongation at break, X‐ray, glass transition temperature, thermal gravemetry, differential scanning calorimetry, degree of crystallinity, and SEM microanalysis. Static conductivity, mobility carrier's concentration, number of charge carriers, and thermoelectric power as a function of PE content were investigated. The temperature dependence of the electrical conductivity as well as the conduction mechanism of IIR–PE blends were also analyzed. The isothermal resistance stability test was examined by displaying the resistance–time curve at certain temperatures. The relationship between current and DC applied voltage was measured for all samples. The self‐electrical heater with PE content of 10 wt % exhibited the highest nonlinearity. The thermal stability was tested by means of temperature–time curve at certain applied power, on and off, for two cycles. Dielectric constant and relative loss factor of the blends are reported. The applicability of the rubber system for switching current, temperature sensor, and electromagnetic shielding effectiveness (EMI) was examined. The experimental results of EMI were compared with theoretical predictions. The results of the present study indicate that these blends are suitable for switching current, temperature‐sensitive sensor, and EMI shielding effectiveness applications with good thermal stability for consumer products. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1125–1138, 2005