含有双酚A链段的聚氨酯网络研究

首先合成与表征了一种含有双酚A结构的多元醇,通过添加这种多元醇至聚氧化丙烯聚醚多元醇中合成了含有双酚A链段的聚氨酯网络。通过DSC、FTIR和SEM等方法考察了这类聚氨酯网络的结构形态,研究结果表明,PU网络中的双酚A链段与聚氧化丙烯链段不相容,而且破坏了PU硬段的有序化结构。在聚氧化丙烯聚醚多元醇中添加5－10phr双酚A结构的多醇就能显著地提高聚氨酯网络的拉伸强度、弹性模量和断裂伸长率。     

Effects of Bisphenol A and Its Alternatives,Bisphenol F and Tetramethyl Bisphenol F on Osteoclast Differentiation

Bisphenol A (BPA) is a typical environmental endocrine disruptor that exhibits estrogen-mimicking, hormone-like properties and can cause the collapse of bone homeostasis by an imbalance between osteoblasts and osteoclasts. Various BPA substitutes, structurally similar to BPA, have been used to manufacture ‘BPA-free’ products; however, the regulatory role of BPA alternatives in osteoclast differentiation still remains unelucidated. This study aimed to investigate the effects of these chemicals on osteoclast differentiation using the mouse osteoclast precursor cell line RAW 264.7. Results confirmed that both BPA and its alternatives, bisphenol F and tetramethyl bisphenol F (TMBPF), were nontoxic to RAW 264.7 cells. In particular, tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell staining and activity calculation assays revealed that TMBPF enhanced osteoclast differentiation upon stimulation of the receptor activator of nuclear factor-kappa B ligand (RANKL). Additionally, TMBPF activated the mRNA expression of osteoclast-related target genes, such as the nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CtsK). Western blotting analysis indicated activation of the mitogen-activated protein kinase signaling pathway, including phosphorylation of c-Jun N-terminal kinase and p38. Together, the results suggest that TMBPF enhances osteoclast differentiation, and it is critical for bone homeostasis and skeletal health.     

微波条件下双酚A向食品模拟物的迁移研究

采用气相色谱-质谱联用法研究了微波条件对食品接触材料中双酚A在水、乙酸（3%,体积分数）、乙醇（10%,体积分数）、橄榄油4种食品模拟物中迁移行为的影响。在微波加热下,食品快速升温并能将热量传递给外部包装,从而加速包装材料中双酚A向食品的迁移。研究了不同微波温度、时间和功率下双酚A在4种食品模拟物中的迁移规律,结果表明：微波对双酚A迁移有显著影响,迁移量随着微波温度、时间和功率的增加而增加。在相同加热温度和时间条件下,微波加热方式中双酚A在4种食品模拟物种的迁移量均高于水浴加热。     

In situ FTIR and DSC investigation on cure reaction of liquid aromatic dicyanate ester with different types of epoxy resin

Cure reactions of a liquid aromatic dicyanate ester [1,1′‐bis(4‐cyanatophenyl) ethane, DiCy] associated with a liquid cycloaliphatic epoxy ester (3,4‐epoxycyclohexylmethyl‐3,4‐epoxycyclohexane‐carboxylate, EPC) and with liquid bisphenol A epoxide [2,2‐bis(4‐glycidyloxyphenyl)propane, EPA] were studied through a cross‐reference between in situ FTIR and DSC dynamic scanning. DiCy can act here as a latent catalyst to cure EPC and EPA resins. Reaction mechanisms were found to be different for both curing systems (EPC/DiCy and EPA/DiCy). Two significantly separated exotherms were observed in the DSC thermograms in each system. The reaction mechanism of the EPA/DiCy system was found to follow mainly Bauer pathways. We postulate a new sequence of the mechanism in this system due to the presence of an oxazoline structure during the progression of the curing process. In the curing system of EPC/DiCy, however, another five principle reaction paths, rather than Bauer pathways, are suggested: (1) polycyclotrimerization of DiCy, (2) formation of oxazoline, (3) insertion of EPC into cyanurate, (4) formation of tetrahydro–oxazolo–oxazole, and (5) ring cleavage and reformation of oxazoline to form the insertion structure of cyanurate. The lower temperature peak in the DSC thermogram is primarily contributed by the former three reaction paths, whereas the higher temperature peak can mainly be attributed to the reaction paths 4 and 5. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2934–2944, 2000     

Synthesis and characterization of poly(aryl ether imide)s containing electroactive perylene diimide and naphthalene diimide units

The synthesis and polymerization of two new electroactive bisphenols derived from 3,4,9,10‐perylenetetracarboxylic dianhydride and 1,4,5,8‐naphthalenetetracarboxylic dianhydride with 2‐(4‐aminophenyl)‐2‐(4‐hydroxyphenyl)propane, respectively, are described. Copolymerization using the two new bisphenols and 4,4′‐isopropylidenediphenol with bis(4‐fluorophenyl)sulfone and 4,4′‐difluorobenzophenone, afforded a series of soluble electrochromic poly(aryl ether imide)s with glass‐transition temperatures ranging from 160 to 315 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3467–3475, 2000     

Synthesis and characterization of new soluble polyesters derived from various cardo bisphenols by solution polycondensation

A series of new polyesters was prepared from terephthaloyl (or isophthaloyl) chloride acid with various cardo bisphenols on solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 150 °C. These polyesters were produced with inherent viscosities of 0.32–0.49 dL · g⁻¹. Most of these polyesters exhibited excellent solubility in a variety of solvents such as N,N‐dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidinone, m‐cresol, and o‐chlorophenol. The polyesters containing cardo groups including diphenylmethylene, tricyclo[5.2.1.0^2,6]decyl, tert‐butylcyclohexyl, phenylcyclohexyl, and cyclododecyl groups exhibited better solubility than bisphenol A–based polyesters. These polymers showed glass transition temperatures (T_g's) between 185 °C and 243 °C and decomposition temperatures at 10% weight loss ranging from 406 °C to 472 °C in nitrogen. These cardo polyesters exhibited higher T_g's and better solubility than bisphenol A‐based polyesters. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4451–4456, 2000     

Self‐decelerated crystallization in blends of polyhydroxyether of bisphenol A and poly(ethylene oxide) upon isothermal crystallization

The growth of spherulites of poly(ethylene oxide) in blends with poly(hydroxyether of bisphenol A) was investigated. In a very narrow range of crystallization temperatures, the spherulite growth deviates from the usual constant growth rate regime in a systematic manner in which the growth rate decreases with time. This is explained by local and overall changes in the composition with the proceeding crystallization that are due to the competition between the crystallization and diffusional chain displacement rates, respectively. These kinetic phenomena and processes can quantitatively be described by a suitable analysis of the experimental findings. Deceleration is predominantly caused by a slowing of the chain motion by the glass‐transition temperature being approached (i.e., vitrification) and, to a lesser extent, by dilution. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1250–1257, 2000     

Attempt to control monomer sequences in copolycondensations of IPA,TPA, BPA,and PHB

Copolycondensations of IPA, TPA, BPA, and PHB were studied to investigate how PHB, which can form mesogenic segments, should be incorporated into the amorphous IPA/TPA–BPA polyester to obtain the thermotropic copolyester, unlike other copolymerizations studied so far by randomly introducing nonmesogenic components into the liquid crystalline polyesters. Random and controlled copolycondensations were attempted to regulate the segment length of mesogenic PHB units by stepwise addition of BPA and PHB through the two- and three-stage reactions using TsCl/DMF/Py as a condensing agent. Thermotropic copolyesters with ca. 40 mol % PHB could be obtained by a three-stage reaction, despite that more than 70 mol % PHB is needed to prepare by usual random copolymerization with PHB. The segment length of the PHB unit was indirectly studied from IPA/TPA–BPA oligomer distribution at initial reaction by means of GPC and from the NMR analysis of the resulting copolymers. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2371–2377, 1999     

Phosphonyl/hydroxyl hydrogen bonding–induced miscibility of poly(arylene ether phosphine oxide/sulfone) statistical copolymers with poly(hydroxy ether) (phenoxy resin): Synthesis and characterization

High molecular weight bisphenol A or hydroquinone‐based poly(arylene ether phosphine oxide/sulfone) homopolymer or statistical copolymers were synthesized and characterized by thermal analysis, gel permeation chromatography, and intrinsic viscosity. Miscibility studies of blends of these copolymers with a (bisphenol A)‐epichlorohydrin based poly(hydroxy ether), termed phenoxy resin, were conducted by infrared spectroscopy, dynamic mechanical analysis, and differential scanning calorimetry. All of the data are consistent with strong hydrogen bonding between the phosphonyl groups of the copolymers and the pendent hydroxyl groups of the phenoxy resin as the miscibility‐inducing mechanism. Complete miscibility at all blend compositions was achieved with as little as 20 mol % of phosphine oxide units in the bisphenol A poly(arylene ether phosphine oxide/sulfone) copolymer. Single glass transition temperatures (T_g) from about 100 to 200°C were achieved. Replacement of bisphenol A by hydroquinone in the copolymer synthesis did not significantly affect blend miscibilities. Examination of the data within the framework of four existing blend T_g composition equations revealed T_g elevation attributable to phosphonyl/hydroxyl hydrogen bonding interactions. Because of the structural similarities of phenoxy, epoxy, and vinylester resins, the new poly(arylene ether phosphine oxide/sulfone) copolymers should find many applications as impact‐improving and interphase materials in thermoplastics and thermoset composite blend compositions. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1849–1862, 1999     

Magnetic sorbent modified by humate for the extraction of alkylphenols,bisphenol A and estradiol

A sorbent has been synthesized from magnetite nanoparticles and a humic acid extracted from sapropel. The sizes of the sorbent nanoparticles and their magnetic core are 218–302 and 14 nm, respectively, the saturation magnetization is 35 emu g^–1. The sorbent provides 87–95% recoveries of alkylphenols, bisphenol A and estradiol with enrichment factors of 1550–1815.