Effect of Residual Maleic Anhydride in PP-g-MAH on the Thermo-Oxidative Aging Properties of RGF-PP

A high number of technical elastomer products contain plasticizers for tailoring material properties. Some additives used as plasticizers pose a health risk or have inadequate material properties. Therefore, research is going on in this field to find sustainable alternatives for conventional plasticizers. In this paper, two modified bio-based plasticizers (epoxidized esters of glycerol formal from soybean and canola oil) are of main interest. The study aimed to determine the influence of these sustainable plasticizers on the properties of acrylonitrile–butadiene rubber (NBR). For comparison, the influence of conventional plasticizers, e.g., treated distillate aromatic extract (TDAE) and Mesamoll® were additionally investigated. Two types of NBR with different ratios of monomers formed the polymeric basis of the prepared elastomers. The variation of the monomer ratio results in different polarities, and therefore, compatibility between the NBR and plasticizers should be influenced. The mechanical characteristics were investigated. In parallel, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were performed and filler macro-dispersion was determined. Bio-based plasticizers were shown to have better mechanical and thermal properties compared to conventional plasticizers. Further, thermo-oxidative aging was realized for 500 h, and afterwards, mechanical characterizations were done. It was observed that bio-based plasticizers have almost the same aging properties compared to conventional plasticizers.

Download Full-text

The UV aging properties of maleic anhydride esterified starch/polylactic acid composites

Journal of Wuhan University of Technology-Mater Sci Ed ◽

10.1007/s11595-017-1698-3 ◽

2017 ◽

Vol 32 (4) ◽

pp. 971-977 ◽

Cited By ~ 4

Author(s):

Yingfeng Zuo ◽

Yiqiang Wu ◽

Jiyou Gu ◽

Yanhua Zhang

Keyword(s):

Maleic Anhydride ◽

Polylactic Acid ◽

Uv Aging ◽

Aging Properties

Download Full-text

Thermo-Oxidative Degradation of Thick-Walled Rubber Materials Studied by IR-Technique and Computed X-Ray Tomography Scanning

Rubber Chemistry and Technology ◽

10.5254/1.3538239 ◽

1990 ◽

Vol 63 (1) ◽

pp. 23-31 ◽

Cited By ~ 11

Author(s):

Bengt Mattson ◽

Bengt Stenberg ◽

Sture Persson ◽

Erik Östman

Keyword(s):

Oxidative Degradation ◽

Attenuated Total Reflection ◽

Low Permeability ◽

Conventional System ◽

X Ray ◽

Oxidative Aging ◽

Aging Properties ◽

Thermal Stability Of ◽

Tomography Scanning ◽

Thermo Oxidative Degradation

Abstract Natural rubber cylinders vulcanized with two different systems, TMTD, which is an efficient vulcanizing system (EV system) and S/CBS, which is a conventional system, have been studied with respect to thermo-oxidative aging gradients, by the ATR-IR-technique (attenuated total-reflection infrared spectroscopy), computed x-ray tomography scanning and swelling. Observed aging processes are dominated by the formation of an oxidized layer whose low permeability to oxygen protects the interior of the material from oxidative aging processes as long as it is intact. The time to the formation of the oxidized layer is the major reason for the differences in the aging gradients. The oxidized layer is formed rapidly in the conventional system, whereas the formation is inhibited by dithiocarbamates in the EV system. Oxygen therefore diffuses into the EV materials, giving deeper oxidative aging than in the conventional materials at the same temperature. The conclusion drawn from the results of this study is that an earlier formation of an oxidized layer is advantageous with respect to thermo-oxidative aging of the bulk. Although it must be stated that, due to the better thermal stability of an EV system and to the poor mechanical properties of an oxidized layer, no objection is here raised to the accepted view that an EV system has superior aging properties.

Download Full-text

Sustainable lignin to enhance asphalt binder oxidative aging properties and mix properties

Journal of Cleaner Production ◽

10.1016/j.jclepro.2019.01.238 ◽

2019 ◽

Vol 217 ◽

pp. 456-468 ◽

Cited By ~ 15

Author(s):

Shams Arafat ◽

Narendra Kumar ◽

Nazimuddin M. Wasiuddin ◽

Ekugbere O. Owhe ◽

Joan G. Lynam

Keyword(s):

Asphalt Binder ◽

Oxidative Aging ◽

Aging Properties

Download Full-text

Investigation of UV Absorber Residue Improving Aging Properties of Bitumen

Materials Science Forum ◽

10.4028/www.scientific.net/msf.847.413 ◽

2016 ◽

Vol 847 ◽

pp. 413-417 ◽

Cited By ~ 2

Author(s):

Li Gao ◽

Jian Ying Yu ◽

Min Wu ◽

Li Hui Xue

Keyword(s):

Aging Process ◽

Retention Rate ◽

Modified Bitumen ◽

Uv Aging ◽

Oxidative Aging ◽

Uv Absorber ◽

Aging Index ◽

Modify Bitumen ◽

Aging Properties ◽

Aging Resistance

Ultraviolet (UV) absorber residue was used to modify bitumen. Effects of UV absorber residue on thermo-oxidative and UV aging properties of bitumen were evaluated by conventional physical properties and SARA (saturates, aromatics, resins and bitumenenes) analysis. The results showed that the viscosity aging index (VAI) and softening point increment (SPI) of bitumen decreased significantly due to introduction of the UV absorber residue, and the ductility retention rate (DRR) was evidently higher compared to the pristine bitumen. SARA show that UV absorber residue can effectively restrain the gelatinization of bitumen resulted from aging. As a consequence, the UV absorber residue modified bitumen displays enhanced aging resistance properties, which can be attributed to the physical sorption of activated carbon to lighter components in the thermo-oxidative aging process and the absorption of UV absorption residue to the ultraviolet light in the process of UV aging.

Download Full-text

Carboxylic Rubbers from Scrap Vulcanized Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3542715 ◽

1957 ◽

Vol 30 (2) ◽

pp. 689-704

Author(s):

Joseph Green ◽

E. F. Sverdrup

Keyword(s):

Maleic Anhydride ◽

Epoxy Resins ◽

Unsaturated Compound ◽

Low Cost ◽

Critical Concentration ◽

Carboxyl Groups ◽

Metallic Oxides ◽

Vulcanized Rubber ◽

Synthetic Rubber ◽

Aging Properties

Abstract Scrap vulcanized rubber has been used principally for the manufacture of reclaimed rubber, which exhibits properties inherent in the original polymers of the scrap. Little has been found in the literature on the utilization of scrap vulcanized rubber as a low-cost starting material for controlled polymer synthesis. In the present investigation scraps containing natural and Type S synthetic rubbers have been modified to produce chemically different polymers possessing properties not usually associated with the initial elastomers. The authors believe that reactions with vulcanized rubber are not usually the same as reactions with the raw polymers and in this work the physical means of accomplishing the reaction are different. In 1938 Bacon and Farmer reported that when masticated raw natural rubber and maleic anhydride were dissolved in a solvent and the solution was heated in the presence of benzoyl peroxide, the ingredients reacted, yielding a variety of tough, fibrous, or resinous products. When vulcanized natural and Type S synthetic rubber scraps were reclaimed in a Reclaimator (a specially designed extruder type plasticator, made by the U. S. Rubber Reclaiming Co., Inc.) in the presence of a critical concentration of certain activated unsaturated compounds, a reaction occurred between the unsaturated compound and the scrap vulcanized rubber. With maleic anhydride, the resulting product was a carboxylated and replasticized rubber. This elastomer exhibited vulcanizing versatility via the carboxyl groups—i.e., curing with bivalent metallic oxides, diamines, glycols, epoxy resins, and diisocyanates. The polarity imparted by the carboxyl groups and the degree of crosslinking of the polymer appear responsible for its oil resistance, a property not normally present in a tire reclaim. The blocking of the double bonds, either by reaction at the double bond or by steric hindrance, added to the good aging properties anticipated with nonsulfur vulcanizates.

Download Full-text

Investigation on Thermo-Oxidative Aging Properties of Asphalt Binder with Hindered Phenolic Antioxidant

Journal of Testing and Evaluation ◽

10.1520/jte20160289 ◽

2017 ◽

Vol 46 (2) ◽

pp. 20160289 ◽

Cited By ~ 2

Author(s):

W. Wu ◽

L. Li ◽

J. Yu ◽

S. Xu ◽

C. Zhang ◽

...

Keyword(s):

Asphalt Binder ◽

Phenolic Antioxidant ◽

Oxidative Aging ◽

Aging Properties

Download Full-text

N-(Morpholinothio)Imides as Curing Agents in Semiefficient Vulcanization Systems

Rubber Chemistry and Technology ◽

10.5254/1.3535762 ◽

1978 ◽

Vol 51 (4) ◽

pp. 764-774 ◽

Cited By ~ 1

Author(s):

P. N. Son ◽

R. A. Krueger

Keyword(s):

Poor Performance ◽

Appreciable Effect ◽

Thermally Stable ◽

Maximum Increase ◽

Oxidative Aging ◽

The Poor ◽

Aging Properties ◽

Curing Agents ◽

Low Levels ◽

Free Sulfur

Abstract It is well known that both the thermal and oxidative aging characteristics of vulcanizates can be improved by using an efficient vulcanization (EV) or semi-EV system. These desirable aging properties are attributed to the presence of mono- and disulfidic crosslinks in the vulcanizates cured by EV or semi-EV systems. In contrast to a polysulfide crosslink, mono- and disulfide crosslinks are more thermally stable and undergo minimal crosslink modification during aging. One way to achieve such desirable properties is to cure a stock with 2-benzothiazyl 4-morpholino disulfide (BMD) and low levels of sulfur. However, the BMD cure system lacks the scorch protection required for many applications. Moreover, neither N-(cyclohexylthio)phthalimide (CTP) nor N,N′-bis(cyclohexylthio)oxanilide (BCTO) shows an appreciable effect on the scorch time of BMD cure systems. This is true regardless of the level of sulfur used, as shown in Figure 1. The maximum increase in scorch time with 1.00 part CTP was only 35%, and this occurred only when three parts of BMD and no free sulfur was used. When 2.00 parts sulfur was used, scorch time was extended only 18%. Likewise, BCTO did not respond well in BMD cure systems. The poor performance of these retarders in BMD cure systems prompted us to design a cure system in which BMD can be formed during vulcanization.

Download Full-text

Study on the Aging Resistance of Polyurethane Precursor Modified Bitumen and its Mechanism

Sustainability ◽

10.3390/su13179520 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9520

Author(s):

Liang Zhang ◽

Pengfei Li ◽

Guanfeng Hu ◽

Sufeng Zhang ◽

Bin Hong ◽

...

Keyword(s):

Mechanical Performance ◽

Thermoplastic Elastomers ◽

Modified Bitumen ◽

Uv Aging ◽

Oxidative Aging ◽

Temperature Performance ◽

Mechanical Methods ◽

Aging Properties ◽

Aging Resistance ◽

The Impact

As an environmentally friendly alternative for the production of high-performance modified asphalt by chemical reactions, a liquid-state polyurethane-precursor-based reactive modifier (PRM) was developed and employed in the asphalt modification. In contrast to the traditional solid bitumen modifier, for example, rubber and thermoplastic elastomers, the PRM as a liquid modifier has more significant advantages in reducing energy consumption and improving asphalt performance, which has attracted widespread attention. However, the aging resistance and its mechanism are not clear. In view of this, the aging performance of two PRM-modified bitumen (PRM-70 and PRM-90), under the short-term thermo-oxidative aging, long-term thermo-oxidative aging, and ultraviolet (UV) aging conditions, was investigated through chemical and mechanical methods. The results show that the PRM-90 is more susceptible to the thermos-oxidative aging and UV aging. The use of low-penetration-grade bitumen and ensuring an adequate reaction are beneficial to enhance the aging resistance of PRM-modified bitumen. The impact of aging on high-temperature performance of PRM-modified bitumen is great, followed by the low-temperature performance and the anti-fatigue performance. The mechanic-relevant rheological aging index (RAI) and fracture energy index (FEI) are recommended to evaluate aging properties for PRM-modified bitumen. This study not only provides support for further research on the relationship between the aging properties and mechanical performance of PRM-modified bitumen, but also provides a reference for conducting mechanism analysis.

Download Full-text

Relationships between the Structures of Natural Rubber Vulcanizates and Their Thermal and Oxidative Aging

Rubber Chemistry and Technology ◽

10.5254/1.3547279 ◽

1970 ◽

Vol 43 (3) ◽

pp. 651-663 ◽

Cited By ~ 27

Author(s):

E. J. Blackman ◽

E. B. McCall

Keyword(s):

Fatigue Life ◽

Fatigue Resistance ◽

Main Chain ◽

Fatigue Behavior ◽

Fatigue Properties ◽

Release Agent ◽

Oxidative Aging ◽

Aging Properties ◽

Natural Rubber Vulcanizates ◽

Sulfur Containing

Abstract Accelerated sulfur NR vulcanizate networks are known to contain poly-, di- and monosulfidic crosslinks, sulfur-containing main chain modifications including cyclic sulfides and pendent accelerator groups, and extra-network material, primarily vulcanization residues. Both oxidative and non-oxidative aging characteristics of the vulcanizate can be improved by use of an efficient or EV curing system. These systems utilize either a high accelerator to sulfur ratio or an accelerator in conjunction with a sulfur release agent to insert predominantly mono- and disulfidic crosslinks, and produce a minimum of main chain modifications. The resulting vulcanizates have excellent aging properties, but fatigue life is poor in comparison to that of a conventional vulcanizate. With a compromise between the conventional and EV curing systems, namely use of intermediate accelerator to sulfur ratios or mixtures of sulfur and sulfur donor, vulcanizates with good fatigue properties and improved aging characteristics can be obtained. Since the most obvious difference between EV and conventional vulcanizate networks is the per cent of monosulfidic crosslinks, it has been assumed that monosulfide crosslinks are responsible for the poor fatigue resistance of EV systems. Recently, it was found that a zinc dimethyldithiocarbamate (ZDC) EV system gave an NR gum vulcanizate having fatigue resistance equal to that of a conventional sulfenamide accelerated compound. The main features of the network are a high percentage of monosulfide crosslinks and extensive main chain modification. In this paper, the aging and fatigue behavior of black filled substituted phenylenediamine protected NR ZDC accelerated systems is examined. The ZDC EV vulcanizate has imaged fatigue resistance equal to that of a conventional sulfenamide accelerated vulcanizate, but oxidative aging is very poor. By decreasing the ZDC/sulfur ratio, a vulcanizate structure equivalent in every measurable way to that of a conventional sulfenamide accelerated system is obtained. Unaged fatigue properties of the two compounds are similar. However, oxidative aging resistance of the ZDC compound is again very poor, and fatigue life of an air aged specimen is virtually zero. It is concluded that fatigue life is not necessarily a function of the crosslink type distribution. Accelerator residues and possibly main chain modifications play an important role insofar as oxidative and non-oxidative aging characteristics are concerned.

Download Full-text