DLTDP

A.ntioxidants. PhenoHc antioxidants, added at about 0.1—0.5 phr, are usually chosen from among butylated hydroxytoluene [128-37-0] (BHT), and Nnonylphenol [104-40-5] for Hquid stabilizer formulations and bisphenol A [80-05-7] (2,2-bis-(/)-hydroxyphenyl)propane) for the soHd systems. Low melting thioesters, dilauryl thiodipropionate [123-28-4] (DLTDP) or distearyl thiodipropionate [693-36-7] (DSTDP) are commonly added along with the phenoHcs to enhance their antioxidant performance. Usually a 3 1 ratio of thiodipropionate to phenoHc antioxidant provides the desired protection. Most mixed metal stabilizer products contain the antioxidant iagredient. 

It should be mentioned that the Food Additives Analytical Manual (FAAM) [75] provides analysts with FDA evaluated methodology (partly subjected to collaborative study) needed to determine compliance with food additive regulations, including procedures for indirect food additives, such as butylated hydroxy-anisole (BHA), butylated hydroxytoluene (BHT), t-butylhydroxyquinone (TBHQ), dilaurylthiopropionate (DLTDP), fatty acid methyl esters (FAME), sodium benzoate, sorbitol, and others. 

C12 to C20, primarily Ci6 to ( is), used as surface lubricants in the manufacture of food-contact articles. The method, which uses ethyl palmitate (Eastman Chemicals No. 1575 Red Label) as an internal standard, has been validated at 200 ppm total FAME [185]. Other FAME standards (methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linolenate) are available (Applied Science Laboratories) [116], Worked out examples of additive determinations are given in the Food Additives Analytical Manual [116], which also describes a great many of indirect food additives, such as BHA, BHT, TBHQ, l-chloro-2-propanol, DLTDP, fatty acid methyl esters, w-heptyl-p-hydroxybenzoate, propyl-gallate, sodium benzoate, sodium stearoyl-2-lactylate, sorbitol and phenolic antioxidants. EPA methods 606 and 8060 describe the CGC separation of phthalate esters (direct injection) (cf. Figure 4.2). 

Table 4.24 summarises the main features of solid-state photolysis-GC for polymer/additive analysis. Photolytic degradation products obtained from PE/1 % DLTDP and PE/1 % DSTDP, PMMA/9 % DNP and PVC/19 % DOP were examined [189]. The method has found little follow-up. 

Squirrell [469] has mentioned TLC of commercial polymer additives (Topanol OC, DLTDP, DSTDP, Ionox 330, Irganox 259/288/1010/1076, Nonox WSP, Polygard, Santonox R, Tinuvin 326/327/328, Topanol CA, UV531, Hoechst D 55, oleamide, erucamide, Ethomeen T12, stearic acid, and others). A TLC procedure has also been described for identification of... 

SEC-FUR is widely used for adhesive analysis [704,706]. Evaporative SEC-FUR has been used for the study of adhesives composed of a high-MW acrylic fraction, a medium-MW PVAc fraction, SBR in the low-MW fraction and a trace amount of dilaurylthiodipropi-onate (DLTDP) in the very low-MW region [706]. The suitability of a moving ZnSe window for SEC-FUR was demonstrated by analysing oligomers in a PS standard mixture [503]. 

LANKROMARK DLTDP AKCROS CHEMICALS FORMER LANKRO CHEMICALS... 

LOWINOX DLTDP GREAT LAKES FORMER LOWI... 

I- Topanol (1,1,3-tri ter-butyl hydroxy methyl phenyl)butane) and Nonox DLTDP (di laurylthiodipropionate) 0.1 wt% in solution II- Santonox-R (4,4 -thio-bis-(6-terbutyl... 

The PE samples were dissolved in TCB at 165°C for 1.5 hrs, then transferred to the SEC injection chamber and after 30 min injected. In the later stage of work, 0.1 wt% of two antioxidants Topanol and Nonox DLTDP were added to the mobile phase only. The chromatograms (see Figure 3 ) were collected and evaluated on Waters Data Module (see Table II ). 

Acrylic elastomer, containing only 0.1 phr Wingstay V and 0.1 phr of DLTDP 1000... 

Representative compounds of importance in polypropylene stabilization are tris( mixed nonyl phenyl) phosphite and dilauryl thiodipropionate-(DLTDP). The aryl phosphite is used in film grade resins and in other... 

CHa—CHjj—li—OR)2 + R OH R equals lauryl(DLTDP), or stearyl(DSTDP)... 

Synergism between Hindered Phenolics and DLTDP in Polypropylene Formulations. When polypropylene is inhibited separately either... 

To determine the relative effectiveness of polymeric phenolic phosphites as heat stabilizers, comparisons were made with several commonly used hindered phenolics. Formulations containing 0.4% DLTDP and 0.1% phenolic were prepared and tested for heat stability in a 300°F. forced-draft oven. Three 75-mil, 1-inch diameter discs were placed in the oven, and days to failure were noted as the time for two out of three discs to craze crumble. 

Table II. Effect of DLTDP—Phenolic Combination with Aryl Phosphite on Heat Aging of Polypropylene...

DLTDP + 0.1% tris(nonyl-phenyl) phosphite (tris) 18... 

Therefore, additional heat aging tests were conducted to investigate the possibility that hydroquinone-derived phenolic groups might function differently from the monohydric phenols and somehow contribute to the high activity of the phenolic-phosphite systems. Two substituted hydro-quinones, two polymeric phenolic phosphites based on those hydro-quinones, and combinations of the hydroquinones with triphenyl phosphite and tris(nonylphenyl) phosphite were evaluated in the oven-aging test again 0.4% DLTDP was included in the formulations. 

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