Monthly changes in the resin yield of semi-sib families of Pinus elliottii during 2013-2015 were studied.The results showed that from April to October,the resin yield of the P.elliottii families was the lowest in Apri...Monthly changes in the resin yield of semi-sib families of Pinus elliottii during 2013-2015 were studied.The results showed that from April to October,the resin yield of the P.elliottii families was the lowest in April and the highest in July.There were significant differences between various families in terms of resin yield.The change of resin yield was closely related to temperature,and the higher the temperature was,the higher the resin yield was.P.elliottii mainly produced resin from June to September.展开更多
Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indi...Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, ^13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ℃ under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.展开更多
A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-（4-hydroxyphenyl）terahydrophthalic anhydrideimide（HTAM） was synthesized. The structural characterization of the epoxy-imide resin was conduc...A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-（4-hydroxyphenyl）terahydrophthalic anhydrideimide（HTAM） was synthesized. The structural characterization of the epoxy-imide resin was conducted by FT-IR spectra. 4,4＇-diaminodiphneylmethane（DDM） was used as a curing agent for the epoxy-imide resin. The thermal properties of the cured resin were evaluated with dynamic mechanical analyses（DMA） and thermogravimetric analysis（TGA）. The results showed that the cured resin exhibited a high glass transition temperature（Tg） of 186 ℃ when the molar amount of HTAM was 0.04 mol in the resin. The yields of the cured resin at 800 ℃ raised from 16.45% to 19.41%. The flexural properties were also measured, the flexural strength raised from 79.4 to 95.7 MPa, and the flexural modulus exhibited from 2.6 to 3.0 GPa.展开更多
Poly(butylene terephthalate)-b-poly(tetramethylene glycol) (PBT-b-PTMG) was used as rheology modifier for the epoxy resin. The segmental copolymer formed spherulites in the epoxy medium. This copolymer was very effect...Poly(butylene terephthalate)-b-poly(tetramethylene glycol) (PBT-b-PTMG) was used as rheology modifier for the epoxy resin. The segmental copolymer formed spherulites in the epoxy medium. This copolymer was very effective in endowing yield stresses to the liquid resin. The PTMG segment brought in a lowering of the dissolution temperature of the spherulites in the epoxy gel. The cured resin with PBT-b-PTMG as modifier was two-phase materials. The rheology modifier improved the mechanical properties of the cured resin as well. The flexible PTMG segments, however, were not in favour of the toughening effect of the modifier. This was attributed to the large domain size of the dispersed phase.展开更多
采用“V”字形下降式采脂法,割脂频率为1 d 1次。设置不同侧沟深度(伤及木质部2~3 mm和仅伤及韧皮部)和不同刺激剂(刺激剂D和刺激剂J)的组合处理。结果表明:不同侧沟深度对产脂量和树脂道数量均无显著影响;同一侧沟深度处理下,刺激剂D...采用“V”字形下降式采脂法,割脂频率为1 d 1次。设置不同侧沟深度(伤及木质部2~3 mm和仅伤及韧皮部)和不同刺激剂(刺激剂D和刺激剂J)的组合处理。结果表明:不同侧沟深度对产脂量和树脂道数量均无显著影响;同一侧沟深度处理下,刺激剂D和刺激剂J处理能显著增加产脂量,尤其是刺激剂J对仅伤及韧皮部的处理增脂效果最佳,增脂率达27%;添加刺激剂均能显著促进新生树脂道数量的增加,增长率在257%~398%;添加刺激剂处理能促进树脂道数量增加,但单个树脂道面积会减小。展开更多
基金Supported by National Key Research and Development Plan(2017YFD0600502)Forestry Science and Technology Planning Project of Hunan Province,China(XLK201307-2)
文摘Monthly changes in the resin yield of semi-sib families of Pinus elliottii during 2013-2015 were studied.The results showed that from April to October,the resin yield of the P.elliottii families was the lowest in April and the highest in July.There were significant differences between various families in terms of resin yield.The change of resin yield was closely related to temperature,and the higher the temperature was,the higher the resin yield was.P.elliottii mainly produced resin from June to September.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.JD-1512)
文摘Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, ^13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ℃ under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.
基金Funded by the National Natural Science Foundation of China(No.51572205)the National Natural Science Foundation of Hubei Province,China(No.2014CFB854)the Equipment Pre-Research Joint Fund of EDD and MOE(No.6141A02033209)
文摘A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-（4-hydroxyphenyl）terahydrophthalic anhydrideimide（HTAM） was synthesized. The structural characterization of the epoxy-imide resin was conducted by FT-IR spectra. 4,4＇-diaminodiphneylmethane（DDM） was used as a curing agent for the epoxy-imide resin. The thermal properties of the cured resin were evaluated with dynamic mechanical analyses（DMA） and thermogravimetric analysis（TGA）. The results showed that the cured resin exhibited a high glass transition temperature（Tg） of 186 ℃ when the molar amount of HTAM was 0.04 mol in the resin. The yields of the cured resin at 800 ℃ raised from 16.45% to 19.41%. The flexural properties were also measured, the flexural strength raised from 79.4 to 95.7 MPa, and the flexural modulus exhibited from 2.6 to 3.0 GPa.
基金The project is supported by Ford-China Research and Development Fund.
文摘Poly(butylene terephthalate)-b-poly(tetramethylene glycol) (PBT-b-PTMG) was used as rheology modifier for the epoxy resin. The segmental copolymer formed spherulites in the epoxy medium. This copolymer was very effective in endowing yield stresses to the liquid resin. The PTMG segment brought in a lowering of the dissolution temperature of the spherulites in the epoxy gel. The cured resin with PBT-b-PTMG as modifier was two-phase materials. The rheology modifier improved the mechanical properties of the cured resin as well. The flexible PTMG segments, however, were not in favour of the toughening effect of the modifier. This was attributed to the large domain size of the dispersed phase.
文摘采用“V”字形下降式采脂法,割脂频率为1 d 1次。设置不同侧沟深度(伤及木质部2~3 mm和仅伤及韧皮部)和不同刺激剂(刺激剂D和刺激剂J)的组合处理。结果表明:不同侧沟深度对产脂量和树脂道数量均无显著影响;同一侧沟深度处理下,刺激剂D和刺激剂J处理能显著增加产脂量,尤其是刺激剂J对仅伤及韧皮部的处理增脂效果最佳,增脂率达27%;添加刺激剂均能显著促进新生树脂道数量的增加,增长率在257%~398%;添加刺激剂处理能促进树脂道数量增加,但单个树脂道面积会减小。
