POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Lin-Xuan Han,Ze-Yong Zhao,Cong Deng,Yu-Zhong Wang
Ethylene propylene diene monomer (EPDM) rubber is highly flammable, facing potential fire hazard when it is used as electric cable sheaths, automobile parts, etc. In this work, aiming to reduce fire hazard of EPDM rubber, a piperazine/alkene-containing phosphoramide oligomer poly (2-butene-1,4-dione piperazine fumaroyl phenylphosphonate) (PPFPP) was synthesized and used as charring agent to fabricate intumescent flame retardant with ammonium polyphosphate (APP). When 20 wt% APP/PPFPP (weight ratio: 3:1) was incorporated into EPDM, the flame-retarded EPDM achieved the UL-94 V-0 rating and the limiting oxygen index (LOI) of 27.0%, significantly superior to flame-retarded EPDM consisting of controlled flame retardant PPSPP without alkene and PPFA without phenyl phosphine. In cone calorimeter test, flame retardant consisting of 6.25 wt% PPFPP and 18.75 wt% APP strongly reduced the peak of heat release rate (PHRR) and the peak of smoke production rate (PSPR) of EDPM, diminished approximately by 72% and 60%, respectively. In the case of meeting flame retardancy, mechanical property of flame-retarded EPDM maintained at a high level. Different measurements confirmed that the flame-retardant mechanism of PPFPP is attributed to two aspects. The first one is ascribed to the char-forming action of PPFPP in the presence of alkene and piperazine, playing a barrier role in condensed phase; the second one is due to the gaseous action of phenyl phosphine groups originating from the pyrolysis of PPFPP. In summary, the combination of piperazine and alkene with phenyl phosphine may fabricate an efficient charring agent for the intumescent flame retardation for EPDM.
研究领域:
材料科学
·
防火材料
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Ganggang Zhang,Xinxin Zhou,Kuan Liang,Baochun Guo,Xiaolin Li,Zhao Wang,Liqun Zhang
Covalently cross-linked rubbers are indispensable in many important fields due to their unique entropic elasticity. For rubbers cross-linking, the addition of toxic curing agents, release of toxic volatile organic compounds (VOCs), and recycling of waste rubber are three important issues. A combination of green curing chemistry and efficient recycling into commercial polyolefin rubbers is of great importance. Herein, we demonstrate a facile and promising way to incorporate dynamic covalent bonds into ethylene-propylene-diene monomer (EPDM)/carbon black (CB) composites. The epoxy-functionalized EPDM (e-EPDM) was prepared using an in situ epoxidation reaction and then cured with biobased decanedioicacid (DA) through the reactions between the epoxy groups in e-EPDM and the carboxylic groups in DA. Because of the existence of exchangeable β-hydroxyl ester, the covalently cross-linked networks in e-EPDM/CB composites were able to rearrange their topological structure at high temperature, endowing the composites with recycled and reshaped abilities. More importantly, the recycled e-EPDM/CB composites still exhibit outstanding mechanical properties which can meet the needs of practical applications. This strategy may provide an efficient, green, and sustainable way to address the problems brought from rubbers cross-linking.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Mingchao Wang,Yuan Wang,Xin Chen,Li Liu,Yetao Zhang,Chen Liu
Compared to the traditional open mixing process used for the production of the rubber composites, wet mixing process is a lower shear force mixing method. This article revealed the influence of the open mixing process and the wet mixing process on the microstructure, density, mechanical properties, and ablation performance of ethylene propylene diene monomer (EPDM) rubber/fiber/hollow glass microsphere composite system. The results showed that the wet mixing process increased the fiber length by more than 300% compared to the open mixing process, while the fragmentation rate of the hollow glass beads was reduced by 94.4%, these effectively maintained the structural integrity of the fibers and the hollow glass microsphere filler. By using the wet mixing process, the density of EPDM composite materials can be reduced by about 20%, and the tensile strength and ablation resistance of these composites were also significantly improved. Compared to polyimide fiber and aramid fiber short fibers, the wet mixing process of solution-based rubber had a more significant effect on improving the length and ablation resistance of phenolic fiber and carbon fiber fibers which having poor shear strength.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2021
·Vol. 306
·期 8
·2100184
·
IF 4.367
Chengjie Li,Zun Yuan,Lin Ye
In view of the facile reaction between carboxyl groups and zinc oxide (ZnO), Zn 2+ -carboxyl salt-bonding is constructed in ethylene propylene diene monomer (EPDM) rubber system by grafting reaction of glutamic acid (Glu), serving as sacrificial unit endowed EPDM-g-Glu/ZnO sample with excellent reprocessing and recycling ability. Through reaction of ZnO/methacrylic acid (MAA), EPDM-g-Glu/zinc dimethacrylate (ZDMA) composite is further prepared by in situ formation of ZDMA, and ZDMA is rapidly polymerized to form poly-ZDMA (PZDMA) containing massive Zn 2+ -carboxyl ion pairs once vulcanized, which exhibits fuzzy interface with the matrix. Relative to EPDM/ZDMA, the higher polymerization degree of ZDMA is achieved with the reduction of the size of PZDMA clusters, demonstrating the improvement of interfacial bonding, which results in the formation of a developed crosslinking network structure for EPDM-g-Glu/ZDMA. The mechanical strength, fracture toughness, and hysteresis loss of EPDM-g-Glu/ZDMA-40% show a significant increase in comparison with EPDM/CB-40% and EPDM/ZDMA-40%, meanwhile the relatively lower compression set and slower contact stress relaxation are achieved by energy dissipation mechanism of preferential rupture of Zn 2+ -carboxyl salt-bonding before breakage of covalent bonds during compression aging process, revealing the effective enhancement of durable sealing resilience performance.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 142
·期 1
·e56315
·
IF 2.7
Faxin Du,Gen Liu,Zhangjun Yao,Shengrong Zhou,Qiuhong Wang,Chengqiang Yang,Qian Lu,Pan He,Jiaxuan Cao,Honglin Chen,Yujun Wei,Rui Han,Shuai Zhang,Guang-Zhao Li
Renowned for its oil, heat, and chemical resistance, fluoroelastomer rubber (FKM) also presents notable drawbacks, such as inferior low-temperature performance. In this study, 2,2-trifluoroethylamine (TF) and 2,4-difluorobenzylamine (DF) were grafted onto epoxidized soybean oil (ESBO) to generate two innovative plasticizers: ESBO-TF and ESBO-DF that they were specifically designed to augment the low-temperature performance of FKM. A thorough investigation into the effects of ESBO-TF/DF on FKM/EPDM blends' properties was conducted. The study demonstrated that the integration of ESBO-TF and ESBO-DF enhanced the vital properties of the FKM/EPDM blends, including elongation at break, tear strength, and, significantly, low-temperature performance. There was a noticeable decrease in the glass transition temperature ( T g ), dropping by 3.54 and 2.95°C with the incorporation of 10 phr ESBO-TF and ESBO-DF, respectively. These respective plasticizers showed positive effects on the plasticization and compatibilization of the FKM/EPDM blends, thus proposing a novel methodology for developing new plasticizers for FKM and related blends.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2021
·
IF 5.03
Qingkun Liu,Jia Li,Yunchao Jiang,Chuanbo Cong,Lixin Xu,Ying Zhang,Xiaoyu Meng,Qiong Zhou
The degradation of peroxide-cured EPDM and sulfur-cured EPDM in an acid solution (12.5 ppm H 2 SO 4 +1.8 ppm HF) was investigated, and it was found that the degradation of the two in an acid solution was different. The degradation degree of the sulfur curing system is lower than that of the peroxide curing system. During the aging process, the molecular main chain of the peroxide-cured EPDM was broken, resulting in a double bond and C=O structure. When there is a coagent TAIC in the peroxide curing system, the presence of TAIC delays the degradation time of the EPDM molecular backbone, and the hydrolysis reaction of the TAIC crosslinking point occurs preferentially, which makes the stability of EPDM improved. In addition, regardless of the presence or absence of TAIC, the peroxide-cured EPDM undergoes a crosslinking reaction in the later stage of aging, resulting in an ether-crosslinked structure, thereby improving the damaged crosslinking network. Unlike the degradation of the peroxide curing system, the breakage of the molecular backbone does not occur in the sulfur-cured EPDM, but only an internal crosslinking reaction of the curing precursor occurs, resulting in a crosslinked network dominated by polysulfide bonds, thereby increasing the crosslinking density of the EPDM during the aging process.
研究领域:
材料科学
·
高分子化学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）