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Synthesis and Characterization of Long-Chain Branched Poly(ether imide)s with A3 Comonomers
ACS Applied Polymer Materials ( IF 4.4 ) Pub Date : 2020-01-28 , DOI: 10.1021/acsapm.9b01148
Joseph M. Dennis 1 , Ryan J. Mondschein 1 , Josh D. Wolfgang 1 , Maruti Hegde 1 , Roy Odle 2 , Timothy E. Long 1
Affiliation  

The synthesis of an aromatic trisamine enabled the generation of long-chain branched poly(ether imide)s (LCB-PEIs). The nucleophilic aromatic substitution of 1-chloro-4-nitrobenzene with 1,1,1-tris(4-hydroxyphenyl)ethane resulted in tris((p-nitrophenoxy)phenyl)ethane, and a subsequent reduction afforded tris((p-aminophenoxy)phenyl)ethane (TAPE) in high yields (>90%). Introducing TAPE at low percentages with m-phenylenediamine and bisphenol A dianhydride enabled synthesis of high molecular weight, branched poly(ether imide)s with varied branch lengths. The stoichiometric imbalance and phthalic anhydride end-capping controlled molecular weights. Complementary 1H NMR spectroscopy and size exclusion chromatography (SEC) identified average branch length as a function of TAPE incorporation and provided comparisons in molecular weights and distributions. The melt viscosity and thermal stability at elevated temperatures (∼340 °C) probed the feasibility of melt processing of LCB-PEIs in comparison to linear analogues. At equivalent molecular weight and below 1.5 mol % TAPE, melt viscosities increased at low shear rates. However, increasing TAPE above 1.5 mol % decreased melt viscosities at low shear rates, suggesting a correlation of branch length and polydispersity with melt viscosity. Mechanical testing of injection-molded samples demonstrated minimal changes in tensile and impact properties with branching. The LCB-PEIs herein establish their potential role in molding processes such as blow molding that requires high melt strength and advantageous shear thinning.

中文翻译:

A 3共聚单体的长链支链聚醚酰亚胺的合成与表征

芳族三胺的合成使得能够产生长链支化聚醚酰亚胺(LCB-PEI)。用1,1,1-三(4-羟苯基)乙烷对1-氯-4-硝基苯进行亲核芳香取代反应生成三((硝基苯氧基)苯基)乙烷,随后还原得到三((氨基苯氧基) )苯基)乙烷(TAPE),收率高(> 90%)。在低百分比与引入TAPE苯二胺和双酚A二酐启用高分子量的合成的,支链的聚(醚酰亚胺)具有不同分支的长度。化学计量不平衡和邻苯二甲酸酐的封端分子量可控制。补充11 H NMR光谱法和尺寸排阻色谱法(SEC)鉴定出平均分支长度是TAPE掺入的函数,并提供了分子量和分布的比较。与线性类似物相比,在高温(约340°C)下的熔体粘度和热稳定性证明了LCB-PEI熔体加工的可行性。在当量分子量和低于1.5 mol%TAPE时,熔体粘度在低剪切速率下增加。但是,将TAPE增加到1.5 mol%以上会在低剪切速率下降低熔体粘度,这表明支链长度和多分散性与熔体粘度相关。注塑样品的机械测试表明,拉伸和冲击性能随分支的变化很小。
更新日期:2020-01-29
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